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Gene Flow, Divergence, and Morphological Differentiation in Birds on the Islands of Trinidad and Tobago

Permanent Link: http://ufdc.ufl.edu/UFE0025110/00001

Material Information

Title: Gene Flow, Divergence, and Morphological Differentiation in Birds on the Islands of Trinidad and Tobago
Physical Description: 1 online resource (63 p.)
Language: english
Creator: Wright, Natalie
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: antshrike, bananaquit, bird, divergence, flycatcher, genetic, hummingbird, island, morphology, thrush, tobago, trinidad
Zoology -- Dissertations, Academic -- UF
Genre: Zoology thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: While island floras and faunas have long been studied by evolutionary biologists, the characteristics that help organisms thrive on islands as opposed to continents and why some taxa differentiate on islands and others do not are still unknown. The act of island colonization itself selects for certain taxa, such as volant birds, to be overrepresented in island faunas, and thus adaptations for life on islands are difficult to tease apart from characters useful in island colonization. I studied insular adaptations and genetic divergence in landbirds on the continental islands of Trinidad and Tobago. Having once been connected to continental South America, these islands are home to organisms that are remnant populations of continental species rather than island colonists. Tobago is more insular than Trinidad, having fewer species and being smaller, farther from the continent, and isolated longer. I measured skeletal and plumage characters in seven species of landbird from Tobago, Trinidad, and continental South America: Glaucis hirsuta, Amazilia tobaci, Thamnophilus doliatus, Mionectes oleagineus, Coereba flaveola, Turdus albicollis, and Turdus nudigenis. I sequenced the ND2 region of the mitochondrion in individuals from Trinidad and Tobago for five of these species. In general, birds from more insular locations had shorter wings, tails, bills, and legs than did conspecifics from less insular localities. For example, the wings of Amazilia tobaci are longest on Tobago, shorter on Trinidad, and shortest in Venezuela. Additionally, flight muscles and associated skeletal elements are smaller on Tobago than in conspecifics on Trinidad. These differences may be related to fewer species of potential competitors and predators in more insular locales. Molecular data indicate none of the five species are dispersing regularly across the 40 km between Trinidad and Tobago. Amazilia tobaci and Mionectes oleagineus are highly divergent morphologically and genetically, whereas Coereba flaveola has differentiated genetically but not morphologically. Thamnophilus doliatus differs greatly in morphology between Trinidad and Tobago, but exhibits lower levels of genetic divergence than the above species, while Turdus nudigenis, likely a recent colonist of the islands, exhibits the lowest measures of genetic divergence and the fewest morphological differences between Trinidad and Tobago.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Natalie Wright.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Steadman, David W.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-08-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0025110:00001

Permanent Link: http://ufdc.ufl.edu/UFE0025110/00001

Material Information

Title: Gene Flow, Divergence, and Morphological Differentiation in Birds on the Islands of Trinidad and Tobago
Physical Description: 1 online resource (63 p.)
Language: english
Creator: Wright, Natalie
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: antshrike, bananaquit, bird, divergence, flycatcher, genetic, hummingbird, island, morphology, thrush, tobago, trinidad
Zoology -- Dissertations, Academic -- UF
Genre: Zoology thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: While island floras and faunas have long been studied by evolutionary biologists, the characteristics that help organisms thrive on islands as opposed to continents and why some taxa differentiate on islands and others do not are still unknown. The act of island colonization itself selects for certain taxa, such as volant birds, to be overrepresented in island faunas, and thus adaptations for life on islands are difficult to tease apart from characters useful in island colonization. I studied insular adaptations and genetic divergence in landbirds on the continental islands of Trinidad and Tobago. Having once been connected to continental South America, these islands are home to organisms that are remnant populations of continental species rather than island colonists. Tobago is more insular than Trinidad, having fewer species and being smaller, farther from the continent, and isolated longer. I measured skeletal and plumage characters in seven species of landbird from Tobago, Trinidad, and continental South America: Glaucis hirsuta, Amazilia tobaci, Thamnophilus doliatus, Mionectes oleagineus, Coereba flaveola, Turdus albicollis, and Turdus nudigenis. I sequenced the ND2 region of the mitochondrion in individuals from Trinidad and Tobago for five of these species. In general, birds from more insular locations had shorter wings, tails, bills, and legs than did conspecifics from less insular localities. For example, the wings of Amazilia tobaci are longest on Tobago, shorter on Trinidad, and shortest in Venezuela. Additionally, flight muscles and associated skeletal elements are smaller on Tobago than in conspecifics on Trinidad. These differences may be related to fewer species of potential competitors and predators in more insular locales. Molecular data indicate none of the five species are dispersing regularly across the 40 km between Trinidad and Tobago. Amazilia tobaci and Mionectes oleagineus are highly divergent morphologically and genetically, whereas Coereba flaveola has differentiated genetically but not morphologically. Thamnophilus doliatus differs greatly in morphology between Trinidad and Tobago, but exhibits lower levels of genetic divergence than the above species, while Turdus nudigenis, likely a recent colonist of the islands, exhibits the lowest measures of genetic divergence and the fewest morphological differences between Trinidad and Tobago.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Natalie Wright.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Steadman, David W.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-08-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0025110:00001


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GENE FLOW, DIVERGENCE, AND MORPHOLOGICAL DIFFERENTIATION IN BIRDS ON THE ISLANDS OF TRINIDAD AND TOBAGO By NATALIE A. WRIGHT A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2009 1

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2009 Natalie A. Wright 2

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To Mom, who instilled in me a love of nature Dad, who encouraged me to chase my dreams, and Mr. Campbell, who taught me th e elegance of evolutionary biology 3

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ACKNOWLEDGMENTS I thank all collectors and prep arators of museum specimens, without whom work of this kind would be impossible. I thank Andrew Kr atter for teaching me how to prepare bird specimens, James Dean of the Smithsonian Nation al Museum of Natural History for access to specimens, and Andrew Kratter, David Stead man, EricaRose Egan, Jessica Oswald, Amy Schwarzer, Howard Nelson, and Ellie Nelson fo r assistance in the field. David Steadman, Rebecca Kimball, Ed Braun, Carol Chaffee, Jena Chojnowski, Kin-Lan Han, and Jordan Smith provided much appreciated and insightful commen ts on earlier versions of this manuscript. EricaRose Egan provided assistance with DNA data collection. Laboratory work was funded with grants from the Frank Chapman Memorial Fund of the American Museum of Natural History and from the University of Florida Department of Zoology. 4

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TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4 LIST OF TABLES................................................................................................................. ..........6 LIST OF FIGURES.........................................................................................................................7 ABSTRACT.....................................................................................................................................8 CHAPTER 1 AVIAN MORPHOLOGICAL DIFFERENTIATION ON THE CONTINENTAL ISLANDS OF TRINIDAD AND TOBAGO..........................................................................10 Introduction................................................................................................................... ..........10 Island Adaptations...........................................................................................................10 Trinidad and Tobago.......................................................................................................11 Methods..................................................................................................................................14 Results.....................................................................................................................................16 Flight Apparatus..............................................................................................................16 Wings and Legs...............................................................................................................18 Bill Size...........................................................................................................................19 Tail Length.................................................................................................................... ..19 Body Mass.......................................................................................................................20 Discriminant Function Analysis......................................................................................20 Discussion...............................................................................................................................22 2 GENE FLOW AND DIVERGENCE IN LANDBIRDS ON THE ISLANDS OF TRINIDAD AND TOBAGO..................................................................................................33 Introduction................................................................................................................... ..........33 Methods..................................................................................................................................36 Results.....................................................................................................................................37 Discussion...............................................................................................................................38 APPENDIX 1 SPECIMENS USED............................................................................................................... 43 2 SKELETAL MEASUREMENTS..........................................................................................58 LIST OF REFERENCES...............................................................................................................59 BIOGRAPHICAL SKETCH.........................................................................................................63 5

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LIST OF TABLES Table page 2-1 Morphological characters of species on Tobago relative to Trinidad................................42 2-2 Measures of genetic divergen ce between Trinidad and Tobago........................................42 6

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LIST OF FIGURES Figure page 1-1 Sternal keel lengths of birds on Trinidad and Tobago.......................................................27 1-2 Ulna lengths of A) Amazilia tobaci and B) Thamnophilus doliatus..................................29 1-3 Tarsometatarsus lengths for A) Glaucis hirsuta B) Thamnophilus doliatus, C) Mionectes oleagineus and D) Coereba flaveola ...............................................................30 1-4 Rostra lengths of A) Glaucis hirsuta B) Thamnophilus doliatus, and C) Mionectes oleagineus ..........................................................................................................................31 1-5 Tail lengths of A) Glaucis hirsuta B) Amazilia tobaci, and C) Coereba flaveola ............32 7

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Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science GENE FLOW, DIVERGENCE, AND MORPHOLOGICAL DIFFERENTIATION IN BIRDS ON THE ISLANDS OF TRINIDAD AND TOBAGO By Natalie A. Wright August 2009 Chair: David W. Steadman Major: Zoology While island floras and faunas have long been studied by evolutionary biologists, the characteristics that help organi sms thrive on islands as opposed to continents and why some taxa differentiate on islands and othe rs do not are still unknown. The act of island colonization itself selects for certain taxa, such as volant birds, to be overrepresented in island faunas, and thus adaptations for life on islands are difficult to t ease apart from characters useful in island colonization. I studied insular adaptations and ge netic divergence in landb irds on the continental islands of Trinidad and Tobago. Having once been connected to continental South America, these islands are home to organisms that are remnant populations of cont inental species rather than island colonists. Tobago is more insular than Trinidad, having fewer species and being smaller, farther from the continent, and isolated longer. I measured skeletal and plumage character s in seven species of landbird from Tobago, Trinidad, and continental South America: Glaucis hirsuta Amazilia tobaci Thamnophilus doliatus, Mionectes oleagineus, Coereba flaveola Turdus albicollis and Turdus nudigenis. I sequenced the ND2 region of the mitochondrion in individuals from Trinidad and Tobago for five of these species. 8

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9 In general, birds from more insular locations ha d shorter wings, tails, bills, and legs than did conspecifics from less insular lo calities. For example, the wings of Amazilia tobaci are longest on Tobago, shorter on Trinidad, and shortest in Venezuela. Additionally, flight muscles and associated skeletal elements are smaller on Tobago than in conspecifics on Trinidad. These differences may be related to fewer species of potential competitors and predators in more insular locales. Molecular data indicate none of the five spec ies are dispersing regularly across the 40 km between Trinidad and Tobago. Amazilia tobaci and Mionectes oleagineus are highly divergent morphologically and genetically, whereas Coereba flaveola has differentiated genetically but not morphologically. Thamnophilus doliatus differs greatly in morphology between Trinidad and Tobago, but exhibits lower levels of geneti c divergence than the above species, while Turdus nudigenis, likely a recent colonist of the islands, exhibits the lowest measures of genetic divergence and the fewest morphological di fferences between Trinidad and Tobago.

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CHAPTER 1 AVIAN MORPHOLOGICAL DIFFERENTIATION ON THE CONTINENTAL ISLANDS OF TRINIDAD AND TOBAGO Introduction Island Adaptations For as long as biologists have been studying evolution, they have been intrigued by island avifaunas (e.g., Darwin 1859, Wallace 1881). Birds on islands often differ from their continental relatives in predictable ways, presumably as ad aptations to insular selection pressures. For example, many insular birds have lost dispersal abilities through the evolution of flightlessness (Steadman 2006) or an apparent reluctance to cross water (Mayr and Diamond 2001), which may be related to a reduction in ove rall energy expenditure on islands in the absence of native mammalian predators (McNab 2002). Islands are characterized by having species -impoverished floras and faunas, which potentially allow each species acces s to a larger share of resour ces. Indeed, evidence suggests that many insular bird species occupy wider ecological niches than their continental relatives (e.g., Grant 1965, Grant 1998, Keast 1970, Scott et al. 2003, Schlotfeldt and Kleindorfer 2006). These niche expansions are sometimes correlated with specific morphological changes, such as a larger bill for feeding on a wider range of food items and/or longer legs for a greater variety of foraging and perching capabilities (Grant 1965, Grant 1968, Feinsinger and Swarm 1982, Clegg and Owens 2002). For non-avian vertebrates, much attention has also been given to the island rule, which describes the trend on islands fo r large animals to become smaller and small animals larger (Van Valen 1973, Lomolino 1985). Th is rule has been widely debated for mammals (e.g., Meiri et al. 2006), but has been assumed not to apply to birds (Grant 1965, Gaston and Blackburn 1995) unt il recently (Clegg and Owens 2002, Robinson-Wolrath and Owens 2003). 10

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Most of our understanding of intraspecific insular adaptations has been based on data collected as part of behavior al and ecological studies, and thus morphological information necessarily comes from measurements taken on live birds (e.g., Grant 1965, Feinsinger and Swarm 1982, Clegg et al. 2002, Schlotfeldt and Kleindorfer 2006). These characters have been limited to a few measurements, such as bill propo rtions, tarsus length, body mass, tail length, and wing chord, the latter two of which may be problema tic because of variati on in feather wear and molt. Potentially important characters, such as those related to the flight muscles, individual wing and leg elements, and the trunk skeleton, have been overlooked because they cannot be measured on live birds. Nothing is known about how flight muscles, for example, might change in response to insular selection pressures. To investigate how a wider range of morphological characters might differ in birds on different is lands, I used museum skeletal specimens and associated data rather than measurements taken on live birds. Trinidad and Tobago The nearby islands of Trinidad (4578 km2) and Tobago (298 km2) offer an excellent opportunity to study insular adapta tions in birds. The two islands are not oceanic; they were connected to the South American continent during the late Pleisto cene glacial interval from ca. 30,000 until 11,000 (Trinidad) and 14,000 (Tobago) years ago (Comeau 1991, Rohling et al. 1998). Thus the starting point for the accumulati on of insular adaptations is known. Another result of this land connection is that the avifa unas of Trinidad and Tobago are primarily subsets of that of nearby Venezuela (ffrench 1991, H ilty 2003) rather than communities of island colonists. As a result, potent ial confounding effects of selec tion for colonization ability are removed from the effects of insular selection pres sures. Furthermore, because dispersal need not be invoked to account for the presence of my st udy species on either Trinidad or Tobago, it is unlikely that a founder effect was involved during establishment of the insular populations. 11

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Finally, the prehistoric record of birds on Trinidad and Tobago over the past several thousand years has disclosed very little extirpation, unlik e in the nearby oceanic islands of the Lesser Antilles (Pregill et al. 1994, Steadman and Stokes 2002, Steadman and Jones 2006, D. W. Steadman pers. comm. ). Insular traits of species s hould be more pronounced in the sm aller, more isolated islands with fewer species than on larger islands clos er to a continent (Lomolino 2005). Compared to Trinidad, Tobago is much smaller (298 km2 vs. 4578 km2), lies farther from continental South America (115 km vs. 11 km), has been isolated from the continent longer (14,000 vs. 11,000 years), and has far fewer species of resident landbirds (99 vs. 251). Therefore, Tobago should sustain species with more pronounced insular traits than Trinidad. This has been noted from an ecological rather than morphologi cal standpoint in two species of birds. The Barred Antshrike, Thamnophilus doliatus, which has undergone a habitat nich e expansion on Tobago, occurs at all heights in both closed-canopy fore st and secondary growth on Tobago, but is restricted to the understory of secondary growth on Trinidad a nd the continent (Keeler-Wolf 1986). Likewise, the Copper-rumped Hummingbird, Amazilia tobaci uses a wider variety of flower nectar on Tobago relative to Trinidad during the three driest a nd most resource-limited months of the year (Feinsinger and Swarm 1982). Both of these niche e xpansions appear to be in response to the presence of fewer potential competitors on T obago than Trinidad and the South American continent. Inspired by these two ecological studies, I investigated morphologica l insular adaptations in seven species of bird common to Trinidad, Tobago, and continental So uth America, including two hummingbirds, (Rufous-breasted Hermit Glaucis hirsuta and Copper-rumped Hummingbird Amazilia tobaci ), two suboscine passerines (Barred Antshrike Thamnophilus doliatus and 12

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Ochre-bellied Flycatcher Mionectes oleagineus ), and three oscine passerines, (White-necked Thrush Turdus albicollis, Bare-eyed Thrush Turdus nudigenis and Bananaquit Coereba flaveola ). These species differ greatly in their inferre d overwater dispersal abilities and degree of plumage differentiation between Trinidad and Tobago. No species of antbird (Thamnophilidae), including Thamnophilus doliatus is found on oceanic islands, and even major rivers appear to be barriers to dispersal in this group (Bates et al. 2004, Hayes and Sewlal 2004). Tobago contains an endemic subspecies, Thamnophilus doliatus tobagensis which differs from T. d. fraterculus on Trinidad in plumage coloration (ffrench 1991) While some species of hummingbirds and flycatchers can be excellent overwater dispersers, neither Amazilia tobaci nor Mionectes oleagineus occurs on any oceanic island, and Glaucis hirsuta is found on only one oceanic island, Grenada (Raffaele et al. 1998). The subspecies Amazilia tobaci tobaci is endemic to Tobago, whereas A. t. erythronata which differs from A. t. tobaci in plumage coloration, occurs on Trinidad. Tobago populations of neither G. hirsuta nor M. oleagineus are classified as subspecies distinct from thos e on Trinidad (ffrench 1991). Thrushes in general are excellent overwater dispersers (Voelk er et al. 2007), and Turdus nudigenis occurs on four oceanic islands, but Turdus albicollis does not inhabit any. The Bananaquit, Coereba flaveola is widespread and common on nearly every island in the Caribbean (Raffaele et al. 1998), and thus presumably is excelle nt at overwater colonization. There are no recorded intraspecific plumage differences between Trinidad and Tobago in T. nudigenis, T. albicollis or C. flaveola and for each of these the same subspecies occurs on both islands (ffrench 1991). Species th at regularly disperse between Trinidad and Tobago would not be expected to exhibit as many (if any) mor phological differences between populations, because regular gene flow should prevent such differences from evolving. 13

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Methods Complete skeletal specimens and skin specimen s with partial skeletons were prepared for birds collected in Trin idad and Tobago in July 2007 and Ju ly 2008. Before specimen preparation, the mass, wing chord, tail length, and exposed culmen length were measured, and notes on molt and feather wear were recorde d. During preparation, the pectora lis major and supracoracoideus muscles from one side of the body were extrac ted from the carcass and weighed fresh. Two tissue samples (liver, heart, and muscle) were taken from each specimen and frozen immediately. Data on gonads, bursa presence, skull ossifica tion, body molt, and fat were recorded during specimen preparation. Skin and skeletal specimens tissue samples, and associated data were deposited in the Florida Museum of Natural History, with rep licates for each tissue specimen deposited in the Louisiana State Univer sity Museum of Natural Science. The combined masses of each pectoralis major and supracoracoideus were multiplied by two to obtain a total mass of the pectoral flight muscles. Within an individual, the pectoral muscles on either side of the body are of equal si zes, so this should not bi as the data (Kratter, Steadman, and Wright, unpublished data). I then divided the total flight muscle mass of each individual by its body mass, obtaining a valu e that is the percent of the total body mass contributed by the pectoral flight muscles, hereafter called the relative flight muscle size. The pectoralis major and supracoracoideus flight musc les and sternum (including keel) together make up what I hereafter refer to as the flight apparatus. I supplemen ted the samples collected in 2007 and 2008 with other specimens from the Florida Museum of Natura l History and the Smithsonian National Museum of Natural History (see Appe ndix A for a list of all specimens). Using prepared skeletal material, I took the followi ng measurements: craniu m length, rostrum length, rostrum width, rostrum depth, coracoid length, total sternum length, ster num width, keel length, keel depth, humerus length, width of the head of the humerus, ulna length, carpometacarpus 14

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length, femur length, femur shaft width, tibiota rsus length, and tarsometatarsus length (see Appendix B for detailed descriptio ns of these measurements). Data analysis, including t-tests, ANOVAs, and regressions, was conducted using the statistical package SPSS. Discriminant functi on analyses (DFA) were conducted with the statistical package JMP using a linear method w ith stepwise variable selection to determine which morphological characters were most important in differentiating groups. Variables were added to the model until the addition of characters reduced the sample size available and failed to improve the models predictive abilities. Not a ll morphological measurements could be taken for each individual and some characters are missing for a majority of specimens that were not specifically prepared for this project (e.g., rostrum length, wing chord) in some species; consequently, including certain characters in the DFA greatly re duced the sample size. When including a character reduced the sample size fo r any location by half or more, I removed that character from the analysis. To correct for the potentially confounding effects of body size on morphology, I divided each measurement by the femur length. This me thod has the potential to be problematic, however, because some of the study species exhibit interisland diffe rences in femur length; thus using femur lengths to correct for body size may dr ive or obscure differen ces in size-corrected measurements of other elements. Because none of my study species exhibits significant interisland differences in coracoid length, I also divided each morphological measurement by the coracoid length to correct for body size. Because neither method of body size correction significantly changed the results for linear m easurements, I present these data as raw measurements. 15

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Results Flight Apparatus The pectoral flight muscles and associated skel etal structures of the sternum (total length, keel length, and keel depth) are smaller in females than in males for all species except Turdus albicollis (Figure 1-1). Within each sex, individuals collected on Trinidad have larger flight apparatuses than those from Tobago in Glaucis hirsuta, Amazilia t obaci, Thamnophilus doliatus, Mionectes oleagineus, and Coereba flaveola (Figure 1-1). The data for sternum length, keel depth, and relative flight muscle size exhibit trends similar to those for keel length, which is strongly correlated with pect oral flight muscle mass (e.g., Amazilia tobaci regression: R2 = 0.802, p<0.001). Consequently, below I only discuss th e results for keel length measurements. Both female and male Glaucis hirsuta collected on Trinidad have significantly longer keels than in individual s of the same sex from Tobago (t-t est, females: p = 0.033; males: p = 0.002; Figure 1-1A). Males on con tinental South America have si gnificantly smaller keels than on Trinidad (Tamhanes T2, p<0.01, n=12, 14) and exhibit no significant difference from males on Tobago (Tamhanes T2, p=0.75, n=12, 13). G. hirsuta females on continental South America exhibit no significant difference in keel length from Trinidad (Tamhanes T2, p=0.8) or Tobago (p=0.99), but the sample is small (n=3). Individuals of Amazilia tobaci also have significantly longer keels on Trinidad than on Tobago (t-tes t, females: p<0.001; males: p = 0.007; Figure 11B), and females have significantly shorter keel s than males (t-test, p<0.001). Samples from Venezuela are too small for analysis of se xes separately (female n=1, male n=2). Thamnophilus doliatus females have shorter keels than males (t-test, p<0.001; Figure 11C). Males have longer keels on Trinidad than on Tobago (t-test, p = 0.002), whereas females exhibit no significant difference in keel length between the two islands (t-test, p = 0.29). T. doliatus on continental South America have longer keels than on Tobago (Tamhanes T2, males: 16

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p=0.013, n=5, 8; females: p=0.072, n= 4, 8) but exhibit no significan t difference from those on Trinidad (Tamhanes T2, males: p=0.99, n=5, 17; females: p=0.99, n=4, 2). Individuals of Mionectes oleagineus have significantly longer keels on Trinidad than Tobago in both females (t-test, p = 0.001; Figure 1-1D) and males (t-t est, p = 0.048). Individual s on continental South America exhibit no significant difference in keel length from those on Trinidad (Tamhanes T2, females: p=0.85, n=7, 9; males: p=0.90, n=12, 6) or Tobago (females: p=0.12, n=7, 4; males: p=0.61, n=12, 5). The keels of males are longer than in females regardless of location (t-test, p<0.001). Coereba flaveola females exhibit longer keels on Trin idad than Tobago (t-test, p<0.01; Figure 1-1E), whereas males show no significant in terisland difference (t-t est, p = 0.12). Females have significantly shorter keels on Tobago than other Caribbean islands (Tamhanes T2, p=0.032, n=9, 15), but exhibit no significant differ ences between Tobago and continental South America (Tamhanes T2, p=0.8, n=9, 7) or betw een Trinidad and other Caribbean islands (Tamhanes T2, p=1.0, n=8, 15) or continental South America (Tamhanes T2, p=0.54, n=8, 7). Males exhibit no significant di fference among Trinidad, Tobago, other Caribbean islands, and continental South America (ANOVA, p=0.41; n=16, 12, 26, 11). C. flaveola females have significantly shorter keels than males, re gardless of location (t-test, p<0.001). Neither females (t-test, p = 0.83) nor males (t-test, p = 0.506) of Turdus albicollis exhibit interisland differences in keel length, and male s and females do not differ significantly in keel length (t-test, p>0.25; Fi gure 1-1F). Likewise, T. albicollis on continental South America do not differ significantly in keel length from Tr inidad (Tamhanes T2, males: p=0.91, n=14, 4; females: p=0.97, n=5, 5) or Tobago (Tamhanes T2, males: p=0.43, n=14, 5; females: p=0.28, n=5, 3). Turdus nudigenis males have significantly longer ke els than females (t-test, p<0.001; 17

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Figure 1-1G), but males exhibit no interisland di fference in keel length (t-test, male: p = 0.18). Female Turdus nudigenis is the only group in my study in which the keel is shorter on Trinidad than on Tobago, although this sample is extremely small (p = 0.025; n = 2, 2). T. nudigenis on continental South America do not differ significan tly in keel length from Trinidad (Tamhanes T2, males: p=0.91, n=6, 10; females: p=0.34, n=3, 2) or Tobago (Tamhanes T2, males: p=0.70, n=6, 8; females: p=0.70, n=3, 2). Wings and Legs When measured in a variety of ways, the wings of Amazilia tobaci and Thamnophilus doliatus are shorter in individuals collected on Trinidad and continental South America than in conspecifics from Tobago (Figure 1-2). Wing ch ords are shorter on Trinidad than on Tobago in A. tobaci (t-test, p<0.001, n = 22, 20) and male T. doliatus (t-test, p = 0.014, n = 16, 8). Within A. tobaci the humeri, ulnae, and carpometacarpi of individuals from Venezuela and Trinidad are shorter than those from Tobago (ANOVA, humerus: p = 0.001, n = 3, 24, 23; ulna: p<0.001; carpometacarpus: p<0.001, n = 3, 15, 15). Individuals of T. doliatus from Trinidad and the South American continent have shor ter ulnae than conspecifics from Tobago (ANOVA, p = 0.005). The other four study species exhibit no significa nt interisland differences in wing lengths. Birds from Lesser Antillean islands and Toba go tend to have longer legs and feet than conspecifics from Trinidad and continental Cent ral and South America (F igure 1-3). Individuals of Glaucis hirsuta from Trinidad and Tobago have longer tib iotarsi and tarsometatarsi than those from continental South America (ANOVA, tibio tarsus: p <0.001, n = 17, 19, 20; tarsometatarsus: p<0.001). Individuals of Thamnophilus doliatus have longer femora and tarsometatarsi on Tobago than on Trinidad or continental S outh America (ANOVA, femur: p = 0.004, n = 16, 20, 8; tarsometatarsus: p = 0.005). Individuals of Mionectes oleagineus from Tobago have longer femora than those from Trinidad or contin ental South America (ANOVA, femur: p<0.001, n = 9, 18

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15, 20). The tibiotarsi and tarsometatarsi of M. oleagineus are longer on Tobago than those on Trinidad, which are longer than in indivi duals from continental South America (ANOVA, tibiotarsus: p<0.001, n = 9, 11, 19; tarsometatarsus: p<0.001). Individuals of Coereba flaveola from Tobago, Trinidad, and elsewhere in the Caribbean have longer femora than those from contin ental South America (ANOVA, p = 0.003, n = 22, 25, 46, 20). The tibiotarsi and tarsometatarsi of C. flaveola are shorter on Trinidad and Tobago than elsewhere in the Caribbean, alt hough longer than in specimens fr om continental South America (ANOVA, tibiotarsus: p<0.001, n = 19, 16, 43, 20; tarsometatarsus: p<0.001). Amazilia tobaci Turdus nudigenis, and T. albicollis do not exhibit significant interi sland differences in lengths of leg elements. Bill Size Bills are longer on Tobago than on Trinidad for three of the study species (Figure 1-4). The rostra of both Glaucis hirsuta and Thamnophilus doliatus are longer on Tobago than on Trinidad, and longer on Trinidad than con tinental South America (ANOVA, p<0.001). In Mionectes oleagineus the rostrum is longer on Tobago than on Trinidad and continental South America (ANOVA, p = 0.001). The bills of the other four study species do not differ significantly among populations. Tail Length Three species have longer ta ils on Tobago than on Trinidad (Figure 1-5). The tails of Glaucis hirsuta are longer on Tobago than on Trinidad (t-test, p = 0.001), as are those of Amazilia tobaci (t-test, p<0.001). Coereba flaveola has shorter tails on Trinidad than on Tobago, and shorter tails on Tobago than on other Caribbean islands (ANOVA, p<0.001). The other four study species exhibit no signi ficant interisland differe nces in tail length. 19

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Body Mass There is no significant di fference in body mass between Glaucis hirsuta on Trinidad and Tobago (t-test, p = 0.751, n = 25, 23; male: p = 0.757, n = 13, 12; female: p = 0.622, n = 12, 11). Male Amazilia tobaci has greater body mass on Trinidad th an on Tobago (t-test, p = 0.053, n = 8, 9), although female A. tobaci exhibits no significant interisland difference in body mass (t-test, p = 0.507, n = 16, 14). In Thamnophilus doliatus body mass is greater on Tr inidad than Tobago (ttest, male: p = 0.011, n = 17, 8; female: p = 0.023, n = 2, 8). Female Mionectes oleagineus also has greater body mass on Trinidad than on Tobago (t-test, p = 0.010, n = 9, 4), whereas males show no such significant difference (t-test, p = 0.249, n = 3, 5). Coereba flaveola exhibits no significant difference in body mass between Trinid ad and Tobago in males (t-test, p = 0.909, n = 15, 12) or females (t-test, p = 0.203, n = 8, 9), nor does Turdus albicollis (t-test, p = 0.165, n = 9, 8; male: p = 0.179, n = 4, 5; female: p = 0.849, n = 5, 3) or Turdus nudigenis (t-test, p = 0.900, n = 11, 11; male: p = 0.576, n = 9, 9; female: p = 0.402, n = 2, 2). Discriminant Function Analysis Discriminant function analysis (DFA) found the three populations of Glaucis hirsuta to be significantly different (South America n= 15, Trinidad n=11, Tobago n=16; p<0.001), and correctly classified 95.2 % of individuals to location, misclassifying one Trinidad individual as being from South America and one South Ameri ca specimen as grouping with Trinidad. The model featured 12 characters rostrum length (p<0.01), humerus length (p=0.055), keel depth (p=0.064), femur length (p=0.071), ulna length (p =0.11), keel length (p=0 .13), cranium length (p=0.15), coracoid length (p=0.21), carpometacar pus length (p=0.39), ta rsometatarsus length (p=0.52), tibiotarsus length (p =0.55), and sternum length (p=0.87) In this model and in all results to follow, including additional characters did not improve the accu racy of the model and reduced the sample size. 20

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Amazilia tobaci populations on Trinidad, Tobago, and Venezuela are significantly different (Trinidad n=15, Tobago n=14, Venezu ela n=3; p<0.001). The DFA model correctly classified 96.9% of A. tobaci individuals to location, misclass ifying one specimen from Trinidad as grouping with Venezuela. Five characters, ulna length (p<0.001), femur length (p=0.036), keel length (p=0.076), carpometacarpus length (p=0.185), and keel depth (p=0.205), were included in the model. Populations of Thamnophilus doliatus on Trinidad, Tobago, and South America are significantly different (Trinidad n=11, Toba go n=12, South America n=5; p<0.001), and DFA correctly classified 96.5 % of individuals to location, grouping one Trinidad individual with South America. This model included 10 charac ters coracoid lengt h (p<0.01), keel depth (p=0.014), tibiotarsus length (p=0.079), car pometacarpus length (p=0.093), humerus length (p=0.11), femur length (p=0.23), ulna length (p= 0.27), keel length (p=0.62), tarsometatarsus length (p=0.7), and st ernum length (p=0.24). For Mionectes oleagineus DFA correctly classified 91% of individuals to location (South America n=18, Trinidad n=6, Tobago n=9), with th ree South America individuals grouping with Trinidad, and found the populations to be significantly different (p<0.001). Four characters, tibiotarsus length (p<0.001), carpometacarpus le ngth (p<0.01), coracoid length (p=0.138), and femur length (p=0.52), were included in the model. For Coereba flaveola DFA correctly classified 88.7% of individuals to location (South America n=16, Trinidad n=12, Tobago n=10, other Caribbean island n=33) and found the four populations to be significantly di fferent (p<0.001). One Trinidad specimen was misclassified as being from Tobago, two Trinidad individuals were grouped with South America, two Tobago individuals grouped with Trinidad, and one and two South Ameri can individuals grouped with 21

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Tobago and Trinidad, respectively. Twelve characte rs contributed to the model tarsometatarsus (p<0.001), coracoid (p<0.001), ulna (p<0.001), cranium length (p<0.01), humerus length (p=0.023), sternum length (p=0.048), keel length (p=0.096), femur length (p=0.14), carpometacarpus (p=0.33), rostrum length (p=0.59) keel depth (p=0.96), and tibiotarsus length (p=0.99). The DFA model failed to find significan t differences between populations of Turdus albicollis on Trinidad, Tobago, and South America (Trinidad n=5, Tobago n=5, South America n=17; p=0.17). The model correctly classified 85 .2% of individuals to location. The characters keel length (p=0.046), keel depth (p=0.094), ulna length (p=0. 16), tarsometatarsus length (p=0.24), carpometacarpus length (p=0.30), sternu m length (p=0.45), femur length (p=0.49), tibiotarsus length (p=0.54), humerus length (p =0.86), and coracoid length (p=0.90) were included in the model. Turdus nudigenis populations on Trinidad, Tobago, and South America are significantly different under the DFA model (Trinidad n=7, Tobago n=8, South America n=8; p=0.024). The model correctly classified 100% of individuals to location. Ulna length (p=0.027), coracoid length (p=0.051), tarsometatarsus length (p=0.12), humerus length (p=0.13), carpometacarpus length (p=0.21), keel length (p=0.44), tibiotars us length (p=0.50), keel depth (p=0.76), and sternum length (p=0.89) contributed to the model. Discussion In general, birds on Tobago are characteri zed by having smaller flight apparatuses yet longer wings, legs, tails, and bills than conspecifics on Trinidad or cont inental South America. Not all study species follow each of these trends although all species with significant interisland differences in any of these characters follow this pattern, with the single exception of female Turdus nudigenis having smaller flight apparatuses on Trinidad than Tobago. (Note that the 22

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sample of 2 individuals from each island is ex tremely small). None of the six species has significantly shorter wings, legs, tails, or bills on Tobago than on Trinidad. Glaucis hirsuta Amazilia tobaci Thamnophilus doliatus, Mionectes oleagineus, and female Coereba flaveola have significantly la rger flight muscles on Trinidad than Tobago. Larger flight muscles provide greater power, whic h is most important for birds during periods of take-offs or short bursts of speed during sust ained flight (Gill 2007). Quick take-offs are important in avoiding predation, and bursts of speed during flight may be used in territorial battles, reaching food resources before competito rs (e.g., trapline hummin gbirds, Gill 1985), and courtship displays as well as in avoiding predati on. No literature exists on interisland differences in territory size or courtship habits on Trinidad vs. Tobago, and these potential differences would not explain flight muscle diffe rences in non-displaying females. Feinsinger and Swarm (1982) observed that A. tobaci on Trinidad and Tobago spends similar amounts of time in aggressive encounters, implying that this species does not ex hibit interisland differe nces in territoriality. While reduced interspecific competition on Tobago relative to Trinidad has been documented for two of my study species, Amazilia tobaci (Feinsinger and Swarm 1982) and Thamnophilus doliatus (Keeler-Wolf 1986), no evidence suggests th at intraspecific competition or total competition for resources is reduced on Tobago relative to Trinidad. There are, however, important differences in real or potentia l predation pressures between Trinidad and Tobago. Fifteen species of diurnal or crepuscular forest raptors occur regularly on Trinidad, including species that regularly take birds (e.g., Short-tailed Hawk Buteo brachyurus and Ferruginous Pygmy-owl Glaucidium brasilianum; ffrench 1991, Kratter, pers. comm.). Only two species of diurnal forest raptors are found on Tobago: Broad-winged Hawk, Buteo platypterus and Great Black Hawk, Buteogallus urubitinga neither of which is likely to 23

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prey regularly on small birds (ffrench 1991, Kratter, pers. comm .). Amazilia tobaci tends to perch in more exposed areas and vocalize more often on Tobago than Trinidad (Feinsinger and Swarm 1982), as would be expected in response to lower predation pressure. The lower predation pressure on Tobago birds may have allowed th em to reduce energy e xpenditure by decreasing metabolically expensive flight muscles. These di fferences in flight muscle size, previously undocumented in birds, may reflect a preliminary st ep in the loss of disp ersal abilities commonly observed in insular species. Longer legs ( Glaucis hirsuta, Thamnophilus doliatus Mionectes oleagineus and Coereba flaveola ) and bills (G. hirsuta T. doliatus and M. oleagineus ) on Tobago than on Trinidad and continental South America are likely related to hab itat and foraging niche expansions on Tobago relative to Trinidad and th e continent. Longer legs allow use of a greater variety of perches (Grant 1965). Larger bills allow birds to eat larger food items (Grant 1965) or, in nectarivores, drink from larger flowers (Fei nsinger and Swarm 1982) and may be related to an increase in either the mean food size or in the range of sizes of food consumed. Such habitat and foraging niche expansions have been documented for Amazilia tobaci (Feinsinger and Swarm 1982) and T. doliatus (Keeler-Wolf 1986) and are related to the presence of fewer species of hummingbird and forest insectivore co mpetitors, respectively, on Tobago. Whether G. hirsuta M. oleagineus, or C. flaveola have expanded their habitat or foraging niches on Tobago relative to Trinidad has not been studied, but such a situation seems probable, given that far fewer species of hummingbirds, flycatchers, and n ectarivorous passerines occur on Tobago than on Trinidad (ffrench 1991). Longer wings on Tobago than Trinidad or continental South America ( Amazilia tobaci and Thamnophilus doliatus ) and longer tails on Tobago than Trinidad ( Glaucis hirsuta A. tobaci 24

PAGE 25

and Coereba flaveola ) could be related to a variety of factors. Longer wings and tails could provide more lift and greater maneuverabilit y, respectively, compensating for these birds smaller flight muscles. Longer wings in hummi ngbirds are associated with a reduction in territoriality and increase in generalist foraging (Feinsinger and Colwell 1978), and in A. tobaci could be an indication of reduced need for terr itory defense against other species on Tobago in association with a wider foraging niche. The th ree species in this st udy with longer tails on Tobago than Trinidad are all nectarivores; perh aps reduced territoriality and more generalized foraging are involved here as well. Alternativel y, longer wings and tails on Tobago could be the result of interisland differences in sexual selection pressures; such differences have not been noted or studied for any of the species. Wing leng ths have been used regularly as proxies for overall body size (Grant 1965, 1968), but longer wings and tails on T obago are not indicative of greater total body size, because when my study sp ecies differ significantly in body mass between Trinidad and Tobago, it is the Trinid ad populations that are larger. Two species, Turdus albicollis and T. nudigenis do not exhibit sign ificant interisland differences in any morphological character exam ined, with one exception (described above), and Turdus albicollis populations are not signi ficantly different in overall morphology (when analyzed with DFA). There are several possible explanations for this finding. These thrushes may regularly disperse overwater, and such interisland gene flow should prevent the accumulation of differences between populations. One or both species could be a recent colonist to Trinidad and Tobago, and therefore have not been isolated long enough for differences to have evolved. Alternatively, the thrushes, unlike as app ears to be the case for the other study species, could be experiencing similar selection pr essures on Trinidad and Tobago, preventing morphological divergence. 25

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This is the first study to suggest that smaller flight apparatuses are ch aracteristic of volant birds on small islands. The other morphological diffe rences I found among birds of the continent, Trinidad, Tobago, and oceanic Caribbean islands (longer wings, tails, legs, and bills in the more insular populations) have all been previously su ggested as possible avian adaptations to island life (Mayr and Vaurie 1948, Gran t 1965, Clegg and Owens 2002), al though Grant (1965) did not find evidence supporting the idea that longer wing s and tails are characteri stic of island birds, and they have been largely overlooked since. This study highlights the value of examining a greater number of morphologi cal characters, incl uding those that cannot be a ssessed in live birds. The driving force behind the observed morphological differences among birds of continental South America, Tr inidad, Tobago, and other Caribbean islands could be species impoverishment. Far more species of both pot ential predators and competitors exist on continental South America and Trinidad than on Tobago, and more such species inhabit Tobago than oceanic Caribbean islands (ffrench 1991, Ra ffaele et al. 1998, Hilty 2003) These patterns in species richness, in turn, are li kely related to island size and temporal and geographic isolation. Other Caribbean islands of similar sizes should have fewer resident species of birds because they have been geographically isolated from the Ameri can continents for their entire existence, in comparison to Trinidads 11,000 years and Toba gos 14,000 years. Similar morphological trends may be present in other avian species on Trinid ad and Tobago, or even among oceanic Caribbean islands that vary notably in si ze and isolation. Studies on other island systems are needed to understand not only how widespread these morphol ogical patterns are, but also improve our understanding of the factors behind them. 26

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A. B. C. D. Figure 1-1. Sternal keel lengths of birds on Trinidad and Tobago. A) Glaucis hirsuta B) Amazilia tobaci C) Thamnophilus doliatus, D) Mionectes oleagineus E) Coereba flaveola F) Turdus albicollis and G) Turdus nudigenis. 27

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E. F. G. Figure 1-1. Continued 28

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A. B. Figure 1-2. Ulna lengths of A) Amazilia tobaci and B) Thamnophilus doliatus. 29

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A. B. C. D. Figure 1-3. Tarsometat arsus lengths for A) Glaucis hirsuta B) Thamnophilus doliatus, C) Mionectes oleagineus and D) Coereba flaveola 30

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A. B. C. Figure 1-4. Rostra lengths of A) Glaucis hirsuta B) Thamnophilus doliatus, and C) Mionectes oleagineus 31

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32 A. B. C. Figure 1-5. Tail lengths of A) Glaucis hirsuta B) Amazilia tobaci, and C) Coereba flaveola

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CHAPTER 2 GENE FLOW AND DIVERGENCE IN LANDB IRDS ON THE ISLANDS OF TRINIDAD AND TOBAGO Introduction Birds vary greatly in their ove rwater dispersal abilities, in cluding flightless birds that cannot cross water, such as the flightless rails found on oceanic islands worldwide (Steadman 2006), volant taxa that find major rivers to be ba rriers to dispersal, such as many suboscine passerine groups (Bates et al. 2004), and species that are regu larly seen flying overwater among islands, such as some Melanesian pigeons and doves (Mayr and Diamond 2001). In species that are poor overwater dispersers, gene flow among populations on different is lands is unlikely, and consequently, these populations are likely to diverge genetically and morphologically. This divergence increases the intraspe cific diversity of the group, a nd, consequently, the biological diversity of the area as a whole. The converse is true for birds th at are good overwater dispersers with regular gene flow, preventing the accumula tion of genetic or morphological differences. Thus, different dispersal abilities may partiall y explain among-taxa differences on islands in terms of species number, morphological di fferentiation, and genetic divergence. Most studies of avian divergence on isla nds have focused on either morphology (e.g., Grant 1968, Scott et al. 2003) or molecular evol ution (e.g., Kirchman and Franklin 2007, Seutin et al. 1994), but not both. No one has studied both morphological and mo lecular divergence in multiple avian species on the same islands to be tter understand these patterns. The few projects that have examined both molecular and phenotyp ic patterns of divergence in island birds typically focused on just one species and used few morphological characte rs (e.g., Illera et al. 2007, Phillimore et al. 2008). These studies have found complex relationships between molecular divergence and morphological distin ctiveness among island p opulations. Sometimes patterns of morphological and gene tic variation are concordant; in other cases (even within the 33

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same study system), they are not. These complex and often contradicting patterns are unexplained. The nearby islands of Trinidad (4578 km2) and Tobago (298 km2) offer an excellent opportunity to investigate insular differentiation in birds. The two islands are not oceanic; they were connected to the South American continent dur ing the late Pleistocene glacial interval from ca. 30,000 until 11,000 (Trinidad) and 14,000 (Tobago) years ago (Comeau 1991, Rohling et al. 1998) and are now separated by 30 km of water. Thus the starting po int for the potential accumulation of morphological and genetic differe nces is known. Another result of this land connection is that the avifaunas of Trinidad a nd Tobago are primarily subsets of that of nearby Venezuela (ffrench 1991, Hilty 2003) rather than communities of island colonists. Consequently, many poorly dispersing species of birds occur on Trinidad and Tobago, in cluding representatives that are never found on oceanic islands, such as motmots (Momotidae), ov enbirds (Furnariidae), antbirds (Thamnophilidae), and manakins (Piprid ae). Additionally, becaus e overwater dispersal and colonization are not needed to explain the presence of birds on these islands, it is unlikely that a founder effect was invol ved in establishing avian popula tions on Trinidad and Tobago. I studied five species of bird common to Trinidad, Tobago, and continental South America that differ greatly in their inferred overwater dispersal abilities: one hummingbird Copper-rumped Hummingbird Amazilia tobaci ; two suboscine passerines Barred Antshrike Thamnophilus doliatus, and Ochre-bellied Flycatcher Mionectes oleagineus ; and two oscine passerines Bare-eyed Thrush Turdus nudigenis, and Bananaquit Coereba flaveola An extensive morphological study of these taxa on Tr inidad and Tobago is re ported in Chapter 1. No species in the antbird family (Thamnophilidae), including Thamnophilus doliatus, is ever found on oceanic islands, and even major rivers appear to be barriers to dispersal in this 34

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group (Bates et al. 2004, Hayes and Sewlal 2004 ). Tobago sustains an endemic subspecies, Thamnophilus doliatus tobagensis which differs morphological ly (ffrench 1991, Chapter 1, Table 2-1) and ecologically (Keeler-Wolf 1986) from T. d. fraterculus of Trinidad. While both hummingbirds and flycatchers can be excellent overwater dispersers with some species migrating long distances overwater, neither Amazilia tobaci Mionectes oleagineus or any of their congeneric species occurs on any oceanic island. The subspecies Amazilia tobaci tobaci is endemic to Tobago, whereas A. t. erythronata which differs morphol ogically (ffrench 1991; Table 2-1) and ecologically (F einsinger and Swarm 1982) from A. t. tobaci occurs on Trinidad. The Tobago population of M. oleagineus is not classified as a subs pecies distinct from that on Trinidad (ffrench 1991), although th e two populations differ in plumage coloration (Kratter, pers. comm., Wright, pers. observation) and othe r morphological characters (Table 2-1). In contrast, thrushes can be ex cellent overwater dispersers, and Turdus nudigenis occurs on four oceanic islands. There are no intraspecific differences in plumage (ffrench 1991), flight muscle size, sternal keel le ngth, leg length, bill size, wing le ngth, tail length, or body mass (Table 2-1) between Trinidad and Tobago in T. nudigenis but discriminant function analysis found the two populations to be significantly differ ent, correctly sorting 1 00% of individuals to island (Chapter 1). The subspecies T. n. nudigenis occurs on Trinidad, Tobago, and the South American mainland (ffrench 1991, Hilty 2003). The Bananaquit, Coereba flaveola is widespread and common on nearly every island in the Caribbean, and thus presumably is excellent at overwater colonization, ye t it exhibits striking interisland differences in plumage coloration (Raff aele et al. 1998). It has been the focus of many biogeographic studies (e.g., Seu tin et al. 1994, Bellemain et al 2008), which have revealed a complex history of multiple colonizations events, including colonization of continental South 35

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America from the West Indi es (Bellemain et al. 2008). Coereba flaveola does not differ in plumage coloration between Trinidad and T obago (ffrench 1991), but does differ in some morphological characters (Table 2-1). Methods To examine interisland genetic divergen ce, I used museum specimens collected on Trinidad and Tobago during Florida Museum of Natural History (FLMNH) expeditions in 2002, 2007, and 2008. All voucher specimens and most tissu es are housed at FLMNH, with replicate tissues in the Genetic Resource collection at Lo uisiana State University Museum of Natural Science (see Appendix A for a comple te list of all specimens used). DNA was extracted from frozen muscle tissue samples using a PureGene DNA Purification Kit. The ND2 gene of the mitoc hondrion was amplified in all study species under standard PCR conditions, with an annealing te mperature of 52oC. After visualization of DNA via gel electrophoresis, Polyet hylene Glycol Precipitation was used to clean DNA for sequencing. Sequencing was conducted using an Applied Biosys tems Prism 3100-Avant genetic analyzer. Sequences were edited using Sequenche r 4.1 (Gene Codes Corp.). Sequences were then aligned using MacClade 4.0. The total lengths of the aligned ND2 region used in analyses were: Amazilia tobaci : 978 bp, Thamnophilus doliatus: 987 bp, Mionectes oleagineus : 921 bp, Coereba flaveola : 977 bp, and Turdus nudigenis: 991 bp. Mitochondrion-rich breast muscle tissue was used to decrease the chance of amplifying nuclear copies of mitochondrial genes. The identity of each gene was confirmed using BLAST (NCBI) to compare sequences to those of conspecifics or congeners in GenBank. The absence of double peaks in the electropherograms and lack of insertions, deletions, and stop codons suggests that the sequences are of mitochondrial or igin rather than nuclear pseudogenes. 36

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Analyses were performed using DnaSP (L ibrado and Rozas 2009). For each species I calculated: the average number of nucleotide differences between Trinidad and Tobago (Tajima 1983); the number of haplotypes on each island, the number of shared haplotypes, and the number of fixed differences betw een Trinidad and Tobago (Hey 1991); hd, haplotype diversity (Nei 1987); Jukes and Cantor corrected nucleo tide diversity (Lynch and Crease 1990); dxy, the mean nucleotide substitutions per site between Trinid ad and Tobago (Nei 1987); a 2 test of significance of haplotype difference (Nei 1987, Hudson et al. 1992a); and FST, a measure of the proportion of genetic variation between relative to within populations (Hudson et al. 1992b). Results The average number of nucleotide differences between Amazilia tobaci on Trinidad (n=14) and Tobago (n=15) is 1.49. Four haplotypes we re found on Trinidad and two on Tobago, with no haplotypes shared and one fixed difference betw een the islands. Based on this pattern of haplotype distribution, A. tobaci on Tobago is significantly different from Trinidad ( 2=29, df=5, p<0.001). Other measures of genetic differentiati on are high, indicating gene flow is very low (Table 2-2). Thamnophilus doliatus averages 1.67 nucleotide differen ces between Trinidad (n=7) and Tobago (n=4). Trinidad and Tobago share no hapl otypes, with five haplotypes found on Trinidad and two on Tobago, and with no fixed differences. The difference between the two populations is not significant ( 2=11, df=6, p=0.088), and both haplotype and sequenced-based estimates indicate that T. doliatus on Trinidad and Tobago are genetically different (Table 2-2), with little gene flow between the two islands. The average number of nucleotide differences between Mionectes oleagineus on Trinidad (n=4) and Tobago (n=5) is 1.44. Four haplotypes were found on Trinidad, and only one on Tobago, which was not found on Trinidad. Mionectes oleagineus exhibits one fixed difference 37

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between the islands, and the genetic difference between the Trinidad and Tobago populations is not significant ( 2=9.0, df=4, p=0.061). Other measures i ndicate high genetic differentiation (Table 2-2), with little disp ersal between the islands. Coereba flaveola has an average of 2.36 nucleotide di fferences between Trinidad (n=14) and Tobago (n=14). Populations of C. flaveola on Trinidad (four hapl otypes) and Tobago (10 haplotypes) share no haplotypes, but exhibit no fixed differe nces. The two populations are significantly different ( 2=24.4, df=12, p=0.018; Table 2-2). Turdus nudigenis averages 2.39 nucleotide differen ces between Trinidad (n=4) and Tobago (n=5). The two islands share one haplotype, with three haplotypes found on each island. Populations on Trinidad are not significan tly genetically different from Tobago ( 2=6.3, df=4, p=0.18). Other measures indicate some genetic di fferentiation between the islands (Table 2-2). Discussion All five study species exhib it both genetic and morphological (Chapter 1) differentiation between the islands of Trinidad and Tobago, but differ in the degree to which their two populations have diverged. Amazilia tobaci on Tobago differs from A. tobaci on Trinidad in five of seven morphological characters (Table 2-1), and, of the five study species, exhibits the greatest levels of genetic differentia tion between the islands (Table 2-2). Thamnophilus doliatus has the greatest number of morphological differences between Trinidad and Tobago (six of seven characters in Table 1). While leve ls of genetic divergence between T. doliatus populations are not as high as those of A. tobaci Mionectes oleagineus or Coereba flaveola the data indicate fairly high genetic structuring and lo w levels of dispersal (Table 2-2). Mionectes oleagineus on Tobago is significantly different from those on Trinidad for five of seven morphological characters (Table 2-1), agreeing with th e genetic data, which indicate high levels of differentiation be tween the islands (Table 2-2). Coereba flaveola differs in fewer 38

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morphological characters than do A. tobaci T. doliatus or M. oleagineus (Table 2-1), but exhibits greater genetic differentiation and lo wer gene flow between the two islands than T. doliatus, and has levels of gene tic divergence and dispersal similar to those of M. oleagineus (Table 2-2). Of the five study species, Turdus nudigenis is the least different between Trinidad and Tobago, whether by genetic or morphologi cal measurements (T ables 2-1, 2-2), and experiences the greatest amount of interisland dispersal. While Thamnophilus doliatus and Turdus nudigenis exhibit estimates of genetic divergence lower than those the other thr ee study species, the values obtained for T. doliatus and T. nudigenis are indicative of genetic differentiation between Trinidad and Tobago. Lower levels of genetic divergence compared to the other study species coul d be evidence of more regular dispersal between Trinidad and Tobago, but ther e are also other possi ble explanations. The populations simply may not have experienced many new mutations or differential losses of alleles in the rather short time (14,000 years) th e islands have been se parated. Alternatively, a species with lower measures of genetic dive rgence between Trinidad and Tobago could be a more recent colonist of the islands. This is plausible for Turdus nudigenis which seems to have recently colonized several other West Indian is lands (Raffaele et al. 1998), but less likely for Thamnophilus doliatus, for which there is no eviden ce of any island colonization. Both the morphological and genetic ev idence strongly suppo rt the idea that Amazilia tobaci and Mionectes oleagineus do not disperse regularly between Trinidad and Tobago. Molecular data suggest that Coereba flaveola does not disperse regul arly between the islands; the morphological data are equivocal. Th e morphological evidence suggests that Thamnophilus doliatus does not disperse regularly between Trin idad and Tobago, although the molecular data 39

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do not. Both the molecular and morphol ogical data support the hypothesis that Turdus nudigenis disperses at least occasionally between Trinidad and Tobago. The discordance between morphol ogical and molecular data for Thamnophilus doliatus could be explained by interisland di fferences in natural selection pr essures. Low levels of regular gene flow, as seems to be the case for T. doliatus would not overcome strong differential selection for certain morphological characters on Trinidad and Tobago. Conversely, a lack of morphological differentiation between Coereba flaveola on Trinidad and Tobago, despite molecular divergence, could be the result of similar selection pressures on the two islands. Alternatively, in C. flaveola drift may be driving molecular differentiation more quickly than morphological divergence. Despite the excellent overwa ter dispersal abilities of Coereba flaveola evidenced by its presence on almost every Caribbean island (Raffaele et al. 1998), this and ot her studies (Seutin et al. 1994, Bellemain et al. 2008) ha ve found strong genetic struct uring among different island populations. In their phylogeography studies, Seutin et al. (1994) and Be llemain et al. (2008) found that the history of C. flaveola in the Caribbean is marked by quick range expansions followed by long periods of divergence on separate islands. Together, these molecular studies and the remarkable plumage differences across its range (Raffaele et al. 1998) suggest that while C. flaveola is excellent at colonizing islands, once established it does not disperse regularly across water. Mionectes oleagineus is a widespread lowland forest bi rd with little apparent phenotypic differentiation across its range (ffrench 1991, Hilty 2003) but deep molecular phylogenetic divergences (Miller et al. 2008). It is capable of long-distance di spersal across unsuitable habitat, having diversified across the Andes multiple times and is likely currently experiencing gene 40

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flow across the Andes (Miller et al. 2008). It seems counterintuitive for the 30 km of water between Trinidad and Tobago to be a barrier to gene flow in such a species, or for many morphological differences to have arisen in th ese populations. Perhaps th e reason lies in that, while unfamiliar and potentially da ngerous, montane habitat is not ne cessarily deadly for a forest bird dispersing across it. Ocean crossings, however, offer no way for birds such as M. oleagineus to rest without drowning. Previous research has suggested that water presents a greater barri er to dispersal for forest species than for birds occupying open ha bitat (Mayr and Diamond 2001, Hayes and Sewlal 2004). This does not appear to be the case for my study species. Mionectes oleagineus which in Trinidad and Tobago is f ound only in forests (Wright pers. obs.), exhibits measures of genetic divergence comparable to those in Coereba flaveola which is common in a variety of habitats, including meadows, cities, forests, and along beaches (Wright pers. obs. ffrench 1991, Raffaele et al. 1998). Amazilia tobaci which exhibits the greatest measur es of genetic divergence of the study species, is found primarily in forest habitat, but also in edge habi tat and open areas with nectar-producing plants (Wright pers. obs.). Due to difficulty acquiring tissues and specimens from Venezuela, this study is restricted to avian dispersal across the 30 km stretch of water between Trinidad and Tobago. To fully understand the dispersal capabilitie s of these birds, however, samp les from the northern coast of Venezuela (at one point just 11 km from Trinidad) should be included. Additionally, a particularly interesting compar ison would be to examine gene tic and morphological divergence between Trinidad and Tobago populations of non-volan t vertebrates, such as rodents, squamates, or amphibians. 41

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42 Table 2-1. Morphological characters of species on Tobago relative to Trinidad; ns = not significantly different. Adapted from Chapter 1, except for plumage coloration, which is based on ffrench (1991) and Wright ( pers. obs ). Species Flight muscles Leg length Bill length Wing length Tail length Body mass Plumage coloration Amazilia tobaci smaller ns ns longer longer smaller Less copper on back Thamnophilus doliatus smaller longer longer longer ns smaller lighter Mionectes oleagineus smaller longer longer ns ns smaller Darker chest Coereba flaveola Smaller (females); males ns ns ns ns longer ns No difference Turdus nudigenis Larger (females); males ns ns ns ns ns ns No difference Table 2-2. Measures of genetic di vergence between Trinidad and Tobago. Species Shared haplotypes Hd (Trinidad, Tobago) (Trinidad, Tobago) dxy FST Amazilia tobaci 0 0.49, 0.34 0.00056. 0.00035 0.0015 0.70 Thamnophilus doliatus 0 0.90, 0.50 0.0016, 0.0010 0.0019 0.29 Mionectes oleagineus 0 1.00, 0.00 0.0022, 0.00 0.0022 0.50 Coereba flaveola 0 0.59, 0.90 0.00071, 0.0019 0.0024 0.47 Turdus nudigenis 1 0.83, 0.80 0.0037, 0.00081 0.0028 0.20

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APPENDIX A SPECIMENS USED Institution Number Species Locality 1 Locality 2 Collector / Preparator FLMNH 42599 Amazilia tobaci Trinidad Aripo Savannahs, 2 km E Cumuto A. W. Kratter FLMNH 42667 Amazilia tobaci Trinidad Aripo Savannahs, 2 km E Cumuto D. W. Steadman FLMNH 45864 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45879 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45888 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45891 Amazilia tobaci Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45894 Amazilia tobaci Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45899 Amazilia tobaci Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45915 Amazilia tobaci Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 45920 Amazilia tobaci Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 45925 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 45943 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45952 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45957 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45975 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45988 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46002 Amazilia tobaci Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46004 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46009 Amazilia tobaci Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46027 Amazilia tobaci Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright 43

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FLMNH 46046 Amazilia tobaci Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. C. Schwarzer FLMNH 46055 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. C. Schwarzer FLMNH 46367 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 46378 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 46379 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 46386 Amazilia tobaci Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46405 Amazilia tobaci Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46411 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 46413 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 46440 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46464 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46484 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W J. A. Oswald FLMNH 46485 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W J. A. Oswald FLMNH 46518 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W E. A. Egan FLMNH 46522 Amazilia tobaci Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W E. A. Egan FLMNH 46527 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46533 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46536 Amazilia tobaci Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46566 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W E. A. Egan FLMNH 46573 Amazilia tobaci Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W D. W. Steadman NMNH 344146 Amazilia tobaci Venezuela Yacua Paria H. Beatty NMNH 344147 Amazilia tobaci Venezuela Yacua Paria H. Beatty NMNH 344148 Amazilia tobaci Venezuela Yacua Paria H. Beatty NMNH 555688 Amazilia tobaci Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington 44

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NMNH 555689 Amazilia tobaci Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 555690 Amazilia tobaci Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 562505 Amazilia tobaci Trinidad N of Simla P. Houde NMNH 562506 Amazilia tobaci Trinidad Morne Bleu P. Houde NMNH 612949 Amazilia tobaci Trinidad Simla P. Houde NMNH 612950 Amazilia tobaci Trinidad Morne Bleu P. Houde FLMNH 30682 Coereba flaveola Jamaica Kingston A. Cruz FLMNH 30683 Coereba flaveola Jamaica Worthy Park A. Cruz FLMNH 30684 Coereba flaveola Jamaica Captive FLMNH 30685 Coereba flaveola Cayman Islands Grand Cayman D. W. Johnston FLMNH 30686 Coereba flaveola Cayman Islands Grand Cayman D. W. Johnston FLMNH 30687 Coereba flaveola Cayman Islands Grand Cayman D. W. Johnston FLMNH 30688 Coereba flaveola Tobago Scarborough E. L. Woolfenden FLMNH 30689 Coereba flaveola Trinidad Waller Field T. G. Aiken FLMNH 30690 Coereba flaveola Bahamas Grand Bahama B. W. Cooper FLMNH 30692 Coereba flaveola Honduras Brus Laguna FLMNH 30693 Coereba flaveola Costa Rica Isla San Andres D. R. Paulson FLMNH 30694 Coereba flaveola Puerto Rico Aquadilla A. Cruz FLMNH 38217 Coereba flaveola Cayman Islands Grand Cayman D. W. Johnston FLMNH 40068 Coereba flaveola Bahamas Grand Bahama K. Oliver FLMNH 40113 Coereba flaveola Bahamas Turks & Caicos D. W. Steadman FLMNH 40114 Coereba flaveola Bahamas Turks & Caicos D. W. Steadman FLMNH 40117 Coereba flaveola Bahamas Turks & Caicos D. W. Steadman FLMNH 42572 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W M. K. Hart FLMNH 42637 Coereba flaveola Trinidad Aripo Savannahs, 2 km E Cumuto A. W. Kratter FLMNH 42666 Coereba flaveola Trinidad Aripo Savannahs, 2 km E Cumuto D. W. Steadman FLMNH 42670 Coereba flaveola Trinidad Aripo Savannahs, 2 km E Cumuto D. W. Steadman FLMNH 45866 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45883 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45892 Coereba flaveola Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45898 Coereba flaveola Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45902 Coereba flaveola Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45916 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter 45

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FLMNH 45919 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 45927 Coereba flaveola Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 45941 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45960 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45964 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45969 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45972 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45977 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 45995 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46008 Coereba flaveola Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46023 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46026 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46028 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46052 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. C. Schwarzer FLMNH 46369 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 46370 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 46390 Coereba flaveola Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46427 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46435 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46436 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46439 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46461 Coereba flaveola Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46472 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W J. A. Oswald FLMNH 46492 Coereba flaveola Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald 46

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FLMNH 46496 Coereba flaveola Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46511 Coereba flaveola Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W J. A. Oswald FLMNH 46521 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W E. A. Egan FLMNH 46526 Coereba flaveola Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W E. A. Egan FLMNH 46532 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46534 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46537 Coereba flaveola Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 46549 Coereba flaveola Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan NMNH 289798 Coereba flaveola Colombia Magdalena, Santa Marta H. H. Smith NMNH 289825 Coereba flaveola Colombia Magdalena, Santa Marta H. H. Smith NMNH 344275 Coereba flaveola Venezuela Yacua Paria H. Beatty NMNH 346090 Coereba flaveola Brazil Mato Grosso, Tres Barras, Rio Paraguay A. Daveron NMNH 347196 Coereba flaveola Colombia El Dificil M. A. Carriker NMNH 347197 Coereba flaveola Colombia El Dificil M. A. Carriker NMNH 347198 Coereba flaveola Colombia El Dificil M. A. Carriker NMNH 347199 Coereba flaveola Colombia Ocana, Santander M. A. Carriker NMNH 492407 Coereba flaveola Ecuador R. G. McLean NMNH 492408 Coereba flaveola Ecuador R. G. McLean NMNH 500452 Coereba flaveola Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500453 Coereba flaveola Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500454 Coereba flaveola Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500455 Coereba flaveola Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500532 Coereba flaveola Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 502809 Coereba flaveola Jamaica Trelawny Parish, Quickstep D. W. Steadman, J. C. Barber NMNH 502811 Coereba flaveola Jamaica Trelawny Parish, Quickstep D. W. Steadman, J. C. Barber NMNH 553095 Coereba flaveola Jamaica Portland Parish, Hardwar Gap D. W. Steadman, J. C. Barber NMNH 553097 Coereba flaveola Jamaica Portland Parish, Hardwar Gap D. W. Steadman, J. C. Barber NMNH 553098 Coereba flaveola Jamaica Portland Parish, Hardwar Gap D. W. Steadman, J. C. Barber NMNH 553493 Coereba flaveola Bahamas Grand Bahama S. L. Olson, C. A. Meister, H. F. James 47

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NMNH 553570 Coereba flaveola Jamaica St. James, Anchovy A. C. Downer NMNH 555557 Coereba flaveola Bahamas San Salvador S. L. Olson NMNH 555571 Coereba flaveola Bahamas San Salvador S. L. Olson NMNH 555572 Coereba flaveola Bahamas San Salvador S. L. Olson NMNH 555575 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555576 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555577 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555578 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555579 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555580 Coereba flaveola Bahamas San Salvador S. L. Olson, G. K. Pregill, H. F. James NMNH 555693 Coereba flaveola Tobago St. John, Charlotteville L. Eastman NMNH 558992 Coereba flaveola Jamaica Trelawny Parish, Quickstep Davis, Pregill, Hilgartner NMNH 558993 Coereba flaveola Jamaica Trelawny Parish, Quickstep Davis, Pregill, Hilgartner NMNH 558994 Coereba flaveola Jamaica Trelawny Parish, Quickstep Davis, Gordon, Hilgartner, Moore, D. W. Steadman NMNH 559237 Coereba flaveola Jamaica Trelawny Parish, Quickstep M. Stephenson, D. W. Steadman NMNH 559238 Coereba flaveola Jamaica Trelawny Parish, Quickstep M. Stephenson, D. W. Steadman NMNH 561312 Coereba flaveola Brazil Sao Paulo, Taubate H. M. Alvarenga NMNH 562516 Coereba flaveola Trinidad Cumuto P. Houde NMNH 562517 Coereba flaveola Trinidad Arima, N of Simla P. Houde NMNH 562655 Coereba flaveola Panama Bocas del Toro, Bastimentos Island S. L. Olson, J. P. Angle NMNH 611633 Coereba flaveola Panama Bocas del Toro, Isla Colon J. P. Angle, J. P. Dean, R. W. Dickerman NMNH 611634 Coereba flaveola Panama Bocas del Toro, Isla Colon, LaGruta J. P. Angle, J. P. Dean, R. W. Dickerman NMNH 612432 Coereba flaveola Panama Bocas del Toro, Isla Cristobal, bocatorito NMNH 612433 Coereba flaveola Panama Bocas del Toro, Tierra Oscura 48

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NMNH 612593 Coereba flaveola St. Vincent St. Andrew, Indian Bay, SE Kingstown T. J. Parsons NMNH 612594 Coereba flaveola St. Vincent St. George, Indian Bay, SE Kingstown T. J. Parsons NMNH 612595 Coereba flaveola St. Vincent St. George, Indian Bay, SE Kingstown T. J. Parsons NMNH 612596 Coereba flaveola St. Vincent St. George, Indian Bay, SE Kingstown T. J. Parsons NMNH 612597 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612598 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612599 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612600 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612601 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612603 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612604 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 612606 Coereba flaveola St. Vincent St. Andrew, Vermont, NE Vermont Nature Trail T. J. Parsons NMNH 613517 Coereba flaveola Panama Bocas del Toro, Cayo Agua, near Punta Limon S. L. Olson, T. J. Parsons NMNH 613518 Coereba flaveola Panama Bocas del Toro, Cayo Agua, near Punta Limon S. L. Olson, T. J. Parsons NMNH 622311 Coereba flaveola Guyana Wiwitau Mt., E Rupununi Savannah NMNH 622895 Coereba flaveola Guyana Kako River, Makwaima Savannah NMNH 623194 Coereba flaveola Guyana Barima River, East Bank, Washikura River NMNH 623202 Coereba flaveola Guyana Barima River, East Bank, Washikura River FLMNH 39577 Glaucis hirsuta Guyana Potaro-Siparuni FLMNH 42600 Glaucis hirsuta Trinidad Aripo Savannahs, 2 km E Cumuto A. W. Kratter FLMNH 45858 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45861 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45897 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45900 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45912 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter 49

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FLMNH 45917 Glaucis hirsuta Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 45981 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46012 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46014 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46062 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. C. Schwarzer FLMNH 46389 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46422 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46476 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W J. A. Oswald FLMNH 46477 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W J. A. Oswald FLMNH 46491 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46523 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W E. A. Egan FLMNH 46545 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan FLMNH 46550 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan FLMNH 46577 Glaucis hirsuta Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W D. W. Steadman NMNH 344137 Glaucis hirsuta Venezuela Yacua Paria H. Beatty NMNH 344138 Glaucis hirsuta Venezuela Carapito H. Beatty NMNH 344139 Glaucis hirsuta Venezuela Yacua Paria H. Beatty NMNH 555682 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 555683 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 555684 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 560156 Glaucis hirsuta Trinidad Oropouche River lower, Bermudez Ranch P. Houde NMNH 562547 Glaucis hirsuta Panama canal zone, Gamboa, along Charles River S. L. Olson, J. P. Angle NMNH 621395 Glaucis hirsuta Guyana NW, Baramita NMNH 623201 Glaucis hirsuta Guyana Barima River, East Bank, Washikura River FLMNH 26702 Glaucis hirsuta Trinidad Arima Valley E. Wing FLMNH 42587 Glaucis hirsuta Trinidad 1.5 km W Morne Bleu A. W. Kratter FLMNH 42624 Glaucis hirsuta Trinidad Arena Forest, 5 km S San Raphael A. W. Kratter 50

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FLMNH 42635 Glaucis hirsuta Trinidad Arena Forest, 5 km S San Raphael A. W. Kratter FLMNH 42682 Glaucis hirsuta Trinidad Aripo Savannahs, 2 km E Cumuto D. W. Steadman FLMNH 45875 Glaucis hirsuta Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45893 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45896 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W A. W. Kratter FLMNH 45936 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45942 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 46001 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46007 Glaucis hirsuta Tobago 4.0 km ENE Bloody Bay River Bridge; 11o19.03N, 60o35.6W N. A. Wright FLMNH 46039 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46051 Glaucis hirsuta Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. C. Schwarzer FLMNH 46065 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. C. Schwarzer FLMNH 46368 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 46385 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46392 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46412 Glaucis hirsuta Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 46426 Glaucis hirsuta Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46494 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46541 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan FLMNH 46547 Glaucis hirsuta Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan NMNH 362439 Glaucis hirsuta Brazil Para, Rio Xingu, east bank NMNH 492296 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492298 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492301 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492304 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492307 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey 51

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NMNH 492345 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492346 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492348 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492350 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 492354 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 555678 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 555679 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 555680 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 559684 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 560157 Glaucis hirsuta Trinidad Arima, Simla P. Houde NMNH 560159 Glaucis hirsuta Trinidad Arima, Simla P. Houde NMNH 289099 Glaucis hirsuta Grenada Grand Etang G. S. Miller NMNH 289100 Glaucis hirsuta Grenada Grand Etang NMNH 490212 Glaucis hirsuta Panama Canal zone, Pina Beach S. L. Olson, J. Wiese NMNH 492347 Glaucis hirsuta Brazil Para, Belem P. S. Humphrey NMNH 501328 Glaucis hirsuta Panama Canal zone, Curundu S. L. Olson, J. Wiese NMNH 555681 Glaucis hirsuta Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 560158 Glaucis hirsuta Trinidad Arima, Simla P. Houde NMNH 562440 Glaucis hirsuta Brazil Para, Rio Xingu, east bank NMNH 492341 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 491173 Mionectes oleagineus Colombia Antioquia, Zaragoza H. Wagner NMNH 491174 Mionectes oleagineus Colombia Antioquia, Zaragoza H. Wagner NMNH 500449 Mionectes oleagineus Ecuador Esmeraldas, 7 km N Quininde R. G. McLean NMNH 621451 Mionectes oleagineus Guyana NW, Baramita NMNH 622812 Mionectes oleagineus Guyana Mount Roraima, North Slope FLMNH 46444 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46448 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46450 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46498 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46022 Mionectes oleagineus Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46417 Mionectes oleagineus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 46564 Mionectes oleagineus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W E. A. Egan 52

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FLMNH 46570 Mionectes oleagineus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W E. A. Egan NMNH 560184 Mionectes oleagineus Trinidad Arima, Simla P. Houde NMNH 344209 Mionectes oleagineus Venezuela Yacua Paria H. Beatty NMNH 492277 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 492344 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 492352 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 614918 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 614919 Mionectes oleagineus Brazil Para, Belem P. S. Humphrey NMNH 492402 Mionectes oleagineus Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 620167 Mionectes oleagineus Guyana Essequibo, Waruma River NMNH 621452 Mionectes oleagineus Guyana NW, Baramita NMNH 623171 Mionectes oleagineus Guyana Barima River, East Bank, Washikura River NMNH 623209 Mionectes oleagineus Guyana Barima River, East Bank, Washikura River FLMNH 46393 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46490 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46501 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46546 Mionectes oleagineus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W E. A. Egan NMNH 555694 Mionectes oleagineus Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington FLMNH 46470 Mionectes oleagineus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright NMNH 612958 Mionectes oleagineus Trinidad Simla P. Houde NMNH 612959 Mionectes oleagineus Trinidad Simla P. Houde NMNH 344207 Mionectes oleagineus Venezuela Yacua Paria H. Beatty NMNH 344208 Mionectes oleagineus Venezuela Carapito H. Beatty NMNH 344239 Thamnophilus doliatus Venezuela Yacua Paria H. Beatty NMNH 345993 Thamnophilus doliatus Brazil Tres Barras, Rio Paraguay A. Daveron NMNH 345994 Thamnophilus doliatus Brazil Tres Barras, Rio Paraguay A. Daveron NMNH 347136 Thamnophilus doliatus Colombia El Dificil M. A. Carriker FLMNH 45885 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45908 Thamnophilus doliatus Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 45998 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46430 Thamnophilus doliatus Tobago Canoe Bay Beach Resort; 11o08.49N, 60o47.92W N. A. Wright FLMNH 46458 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46555 Thamnophilus doliatus Tobago Canoe Bay Beach Resort; 11o08.49N, 60o47.92W E. A. Egan 53

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FLMNH 46560 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan NMNH 555702 Thamnophilus doliatus Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington FLMNH 46034 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46565 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W E. A. Egan NMNH 344237 Thamnophilus doliatus Venezuela Yacua Paria H. Beatty NMNH 344238 Thamnophilus doliatus Venezuela Yacua Paria H. Beatty NMNH 345992 Thamnophilus doliatus Brazil Tres Barras, Rio Paraguay A. Daveron NMNH 345995 Thamnophilus doliatus Brazil Tres Barras, Rio Paraguay A. Daveron NMNH 347134 Thamnophilus doliatus Colombia El Dificil M. A. Carriker NMNH 490023 Thamnophilus doliatus Brazil Bahia, Rio Sao Francisco, Barra E. G. Holt FLMNH 45873 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45887 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45968 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 46399 Thamnophilus doliatus Tobago Canoe Bay Beach Resort; 11o08.49N, 60o47.92W A. W. Kratter FLMNH 46437 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46438 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46452 Thamnophilus doliatus Tobago Canoe Bay Beach Resort; 11o08.49N, 60o47.92W N. A. Wright FLMNH 46535 Thamnophilus doliatus Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan FLMNH 27260 Thamnophilus doliatus Trinidad Waller Field C. T. Collins FLMNH 45921 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 45929 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 45987 Thamnophilus doliatus Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46030 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46033 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46050 Thamnophilus doliatus Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. C. Schwarzer 54

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FLMNH 46053 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. C. Schwarzer FLMNH 46057 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. C. Schwarzer FLMNH 46058 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. C. Schwarzer FLMNH 46406 Thamnophilus doliatus Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 46463 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46465 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46469 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46562 Thamnophilus doliatus Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W E. A. Egan FLMNH 46568 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W E. A. Egan FLMNH 46578 Thamnophilus doliatus Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W D. W. Steadman NMNH 560170 Thamnophilus doliatus Trinidad Brasso Seco P. Houde FLMNH 42571 Turdus albicollis Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W M. K. Hart FLMNH 42581 Turdus albicollis Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W A. W. Kratter FLMNH 45918 Turdus albicollis Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 46407 Turdus albicollis Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W A. W. Kratter FLMNH 46493 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46497 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46500 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W J. A. Oswald FLMNH 46574 Turdus albicollis Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W D. W. Steadman NMNH 344249 Turdus albicollis Venezuela Yacua Paria H. Beatty NMNH 344250 Turdus albicollis Venezuela Yacua Paria H. Beatty NMNH 562394 Turdus albicollis Brazil Para, Rio Xingu, east bank NMNH 621473 Turdus albicollis Guyana NW, Baramita NMNH 632569 Turdus albicollis Guyana Kopinang Village, Kopinang River 55

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FLMNH 45907 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 45944 Turdus albicollis Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W D. W. Steadman FLMNH 45980 Turdus albicollis Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W N. A. Wright FLMNH 46020 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46394 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W A. W. Kratter FLMNH 46447 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46449 Turdus albicollis Tobago Tobago Forest Reserve; 11o16.78N, 60o37.11W N. A. Wright FLMNH 46460 Turdus albicollis Trinidad 2.7 km SW Morne Bleu; 10o43.0N, 61o18.6W N. A. Wright FLMNH 46475 Turdus albicollis Trinidad 2 km W Morne Bleu; 10o43.5N, 61o18.4W J. A. Oswald NMNH 344251 Turdus albicollis Venezuela Yacua Paria H. Beatty NMNH 492380 Turdus albicollis Brazil Amapa, Rio Amapari E. Dente NMNH 558823 Turdus albicollis Paraguay Itapua, El Tirol M. S. Foster NMNH 558824 Turdus albicollis Paraguay Itapua, El Tirol M. S. Foster NMNH 562392 Turdus albicollis Brazil Para, Rio Xingu, east bank NMNH 562393 Turdus albicollis Brazil Para, Rio Xingu, east bank NMNH 562772 Turdus albicollis Brazil Sao Paulo, Ubatuba H. M. Alvarenga NMNH 620170 Turdus albicollis Guyana Essequibo, Waruma River NMNH 621814 Turdus albicollis Guyana N side Acari Mtns NMNH 621815 Turdus albicollis Guyana N side Acari Mtns NMNH 623124 Turdus albicollis Guyana Kusad Mt, NE flank, South Rupununi Savannah NMNH 635910 Turdus albicollis Uruguay Rocha NMNH 429373 Turdus albicollis Venezuela Amazonas, Rio Yatua A. Wetmore NMNH 562766 Turdus albicollis Brazil Sao Paulo, Ubatuba H. M. Alvarenga FLMNH 42656 Turdus nudigenis Trinidad Aripo Savannahs, 1 km ENE Cumuto D. W. Steadman FLMNH 46434 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46512 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W J. A. Oswald FLMNH 46528 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan NMNH 500522 Turdus nudigenis Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500523 Turdus nudigenis Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 502481 Turdus nudigenis Ecuador Guayas Prov., Huerta Negra R. G. McLean FLMNH 42641 Turdus nudigenis Trinidad Aripo Savannahs, 2 km E Cumuto A. W. Kratter 56

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FLMNH 45878 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 45931 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 45967 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45970 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W D. W. Steadman FLMNH 45994 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W N. A. Wright FLMNH 46031 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46035 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W N. A. Wright FLMNH 46059 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. C. Schwarzer FLMNH 46377 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W A. W. Kratter FLMNH 46418 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W A. W. Kratter FLMNH 46478 Turdus nudigenis Tobago Canoe Bay Beach Resort; 11o08.49N, 60o47.92W J. A. Oswald FLMNH 46487 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W J. A. Oswald FLMNH 46510 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W J. A. Oswald FLMNH 46513 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W J. A. Oswald FLMNH 46516 Turdus nudigenis Trinidad Aripo Valley, LOrange Estate; 10o41.17N, 61o14.05W J. A. Oswald FLMNH 46531 Turdus nudigenis Tobago Canoe Bay Forest; 11o08.5N, 60o47.94W E. A. Egan NMNH 344252 Turdus nudigenis Venezuela Maturin H. Beatty NMNH 500387 Turdus nudigenis Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500389 Turdus nudigenis Ecuador Los Rios, Abras de Mantequilla R. G. McLean NMNH 500456 Turdus nudigenis Ecuador Guayas Prov., Huerta Negra R. G. McLean NMNH 500457 Turdus nudigenis Ecuador Los Rios, Abras de Mantequilla R. G. McLean NMNH 502480 Turdus nudigenis Ecuador Los Rios, Vinces, NE Hacienda Puerto Nuevo R. G. McLean NMNH 555703 Turdus nudigenis Tobago St. John, Charlotteville G. S. Morgan, F. A. Harrington NMNH 560186 Turdus nudigenis Trinidad Quare River P. Houde 57

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58 APPENDIX B SKELETAL MEASUREMENTS Rostrum length: measured from the tip of rostrum maxillare to the naso-frontal hinge. Cranium length: measured from the naso-frontal hinge to point of intersection between the crista nuchalis sagittalis and crista nuchalis transversus. Coracoid length: measured from the proce ss lateralis to processus acrocoracoideus Sternal length: measured from the anterior-most point of the spina in terna to medial-most point of the margo caudalis. Sternal width: measured between th e anterior-most process costalis. Sternal keel length: measured from th e apex carinae to trabecula mediana. Sternal keel depth: measured from the tuberculum labri externus to ventral margin of carina sterni. Humerus length: measured from the proximal-most edge of the caput humeri to the distalmost point of the condyles ventralis. Humerus width: measured from the tubercul um dorsale to the tuberculum ventrale. Ulna length: measured from the proximal-most point of the olecranon to the distal-most point of the condylus ventralis ulnaris. Carpometacarpus length: measured from the pr oximal-most point of the trochlea carpalis to the distal-most point of the ar ticulation for phalanx digiti minoris. Femur length: measured from the proximal-most point of the crista trochanteris to the distal-most point of the condylus lateralis. Femur width: measured the width of the mid-shaft of the femur. Tibiotarsus length: measured fr om the proximal-most point of the crista cnemialis cranialis to the distal-most point of the condylus medialis. Tarsometatarsus length: measured from the proxi mal-most point of eminentia intercotylaris to the distal-most point of the trochlea metatarsi III.

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LIST OF REFERENCES BAKER, A. J., AND H. D. MARSHALL. 1997. Mitochondrial control regi on sequences as tools for understanding evolution. Pages 51-82 in Avian molecular evolution and systematics (D. P. Mindell, Ed.). Academic Press, San Diego, CA. BATES, J. M. 2000. Allozymic genetic structure and natura l habitat fragmentation: data for five species of Amazonian forest birds. The Condor 102:770-783. BATES, J. M., J. HAFFER, AND E. GRISMER. 2004. Avian mitochondrial DNA sequence across a headwater stream of the Rio Tapajs, a majo r Amazonian river. J ournal of Ornithology 145:199-205. BELLEMAIN, E., E. BERMINGHAM, AND R. E. RICKLEFS. 2008. The dynamic evolutionary history of the bananaquit ( Coereba flaveola ) in the Caribbean revealed by a multigene analysis. BMC Evolutionary Biology 8:240-253. COMEAU, P. L. 1991. Geological events influencing natu ral vegetation in Trinidad. Living World (Journal of the Trinidad and Tobago Field Naturalists Club) 1991-1992:29-38. CLEGG, S. M., AND I. P. F. OWENS. 2002. The 'island rule' in birds: medium body size and its ecological explanation. Proceed ings of the Royal Society B-Biological Sciences 269:13591365. CLEGG, S. M., S. M. DEGNAN, C. MORITZ, A. ESTOUP, J. KIKKAWA, AND I. P. F. OWENS. 2002. Microevolution in island forms: the roles of drift and directional selection in morphological divergence of a passerine bird. Evolution 56:2090-2099. DARWIN, C. 1859. The Origin of Species. Murray, London, UK. FEINSINGER, P., AND R. K. COLWELL. 1978. Community organization among Neotropical nectarfeeding birds. Ameri can Zoologist 18:779-795. FEINSINGER, P., AND L. A. SWARM. 1982. Seasonal variation in food supply and the hummingbird Amazilia tobaci on Trinidad and Tobago. Ecology 63:1574-1587. FFRENCH, R. 1991. A Guide to the Birds of Trinidad and Tobago. Cornell University Press: Ithaca, NY. GASTON, K. J., AND T. M. BLACKBURN. 1995. Birds, body size, and the threat of extinction. Philosophical Transactions: Biol ogical Sciences 347:205-212. GILL, F. B. 1985. Hummingbird flight speeds. The Auk 102:97-101. GILL, F. B. 2007. Ornithology. 3rd Edition. W. H. Freeman a nd Company: New York, NY. GRANT, P. R. 1965. The adaptive significance of some size trends in island birds. Evolution 19:355-367. 59

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GRANT, P. R. 1968. Bill size, body size, and the ecologi cal adaptations of bird species to competitive situations on islands. Systematic Zoology 17: 319-333. GRANT, P. R. (Ed.) 1998. Evolution on islands. Oxford University Press: Oxford, UK. Hayes, F. E., AND J-A. N. SEWLAL. 2004. The Amazonian River as a dispersal barrier to passerine birds: effects of river width, habitat, and taxonomy. Journal of Biogeography 31:1809-1818. HEY, J. 1991. The structure of genealogies and the di stribution of the fixed differences between DNA sequence samples from natural populations. Genetics 128:831-840. HILTY, S. L. 2003. Birds of Venezuela. Princet on University Press: Princeton, NJ. HUDSON, R. R., D. D. BOOS, AND N. L. KAPLAN. 1992. A statistical test for detecting population subdivision. Molecular Biol ogy and Evolution 9:138-151. HUDSON, R. R., M. SLATKIN, AND W. P. MADDISON. 1992. Estimation of levels of gene flow from DNA sequence data. Genetics 132:583-589. ILLERA, J. C., B. C. EMERSON, AND D. S. RICHARDSON. 2007. Population histor y of Berthelots pipit: colonization, gene flow and morphological divergence in Macaronesia. Molecular Ecology 16:4599-4612. KEAST, A. 1970. Adaptive evolution and shifts in ni che occupation in island birds. Biotropica 2:61-75. KEELER-WOLF, T. 1986. The Barred Antshrike ( Thamnophilus doliatus) on Trinidad and Tobago: habitat niche expans ion of a generalist forager. Oecologia 70:309-317. KIRCHMAN, J. J., AND J. D. FRANKLIN. 2007. Comparative phylogeography and genetic structure of Vanuatu birds: Control region variation in a rail, a dove, and a passerine. Molecular Phylogenetics and Evolution 43:14-23. LIBRADO, P., AND J. ROZAS. 2009. DnaSP v5: A software for co mprehensive analysis of DNA polymorphism data. Bioinformatics 25:1451-1452. LOMOLINO, M. V. 1985. Body size of mammals on isla nds: the island rule re-examined. American Naturalist 125:310-316. LOMOLINO, M. V. 2005. Body size evolution in insular verteb rates: generality of the island rule. Journal of Biogeography 32:1683-1699. LYNCH, M., AND T. J. CREASE. 1990. The analysis of population survey data on DNA sequence variation. Molecular Biol ogy and Evolution 7:377-394. MAYR, E., AND J. M. DIAMOND. 2001. The Birds of Northern Me lanesia. Oxford University Press, New York, NY. 60

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MAYR, E., AND VAURIE, C. 1948. Evolution in the Family Di cruridae (birds). Evolution 2:238265. MCNAB, B. K. 2002. Minimizing energy expenditure facil itates vertebrate persistence on oceanic islands. Ecology Letters 5:693-704. MEIRI, S., T. DAYAN, AND D. SIMBERLOFF. 2006. The generality of the island rule reexamined. Journal of Biogeography 33:1571-1577. MILLER, M. J., E. BERMINGHAM, J. KLICKA, P. ESCALANTE, F. S. RAPOSO DO AMARAL, J. T. WEIR, AND K. WINKER. 2008. Out of Amazonia again and agai n: episodic crossing of the Andes promotes diversification in a lowland forest flycatcher. Proceedings of the Royal Society B 275:1133-1142. NEI, M. 1987. Molecular Evolutionary Genetics. Co lumbia University Press, New York, NY. PHILLIMORE, A. B., I. P. F. OWENS, R. A. BLACK, J. CHITTOCK, T. BURKE, AND S. M. CLEGG. 2008. Complex patterns of genetic and phenotypic divergence in an island bird and the consequences for delimiting conserva tion units. Molecular Ecology 17:2839-2853. PREGILL, G. K., D. W. STEADMAN, AND D. R. WATTERS. 1994. Late Quaternary vertebrate faunas of hte Lesser Antilles: histor ical components of Caribbean biogeography. Bulletin of the Carnegie Museum of Natural History 30:1-51. RAFFAELE, H., J. WILEY, O. GARRIDO, A. KEITH, AND J. RAFFAELE. 1998. A Guide to the Birds of the West Indies. Princeton Univ ersity Press, Princeton, NJ. ROBINSON-WOLRATH, S. I., AND I. P. F. OWENS. 2003. Large size in an island-dwelling bird: intraspecific competition and the Dominance Hy pothesis. Journal of Evolutionary Biology 16:1106-1114. ROHLING, E. J., M. FENTON, F. J. JORISSEN, P. BERTRAND, G. GANSSEN, AND J. P. CAULET. 1998. Magnitudes of sea-level lowstands of the past 500,000 years. Nature 394:162-165. SATO, A., H. TICHY, C. OHUIGIN, P. R. GRANT, B. R. GRANT, AND J. KLEIN. 2001. On the origin of Darwins finches. Molecula r Biology and Evolution 18:299-311. SCOTT, S. N., S. M. CLEGG, S. P. BLOMBERG, J. KIKKAWA, AND I. P. F. OWENS. 2003. Morphological shifts in island-dwelling birds: the roles of generalist foraging and niche expansion. Evolution 57:2147-2156. SEUTIN, G., N. K. KLEIN, R. E. RICKLEFS, AND E. BERMINGHAM. 1994. Historical biogeography of the Bananaquit ( Coereba flaveola ) in the Caribbean region: a mitochondrial DNA assessment. Evolution 48:1041-1061. SLATKIN, M. 1985. Rare alleles as indicators of gene flow. Evolution 39:53-65. 61

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62 STEADMAN, D. W. 2006. Extinction and biogeography of tropi cal Pacific birds. University of Chicago Press, Chicago, IL. STEADMAN, D. W., AND S. JONES. 2006. Long-term trends in preh istoric fishing and hunting on Tobago, West Indies. Latin American Antiquity 17:316-334. STEADMAN, D. W., AND A. V. STOKES. 2002. Changing exploitation of terrestrial vertebrates during the past 3000 years on Tobago, West Indies. Human Ecology 30:339-367. TAJIMA, F. 1983. Evolutionary relationship of DNA sequences in finite populations. Genetics 105:437-460. VAN VALEN, L. 1973. A new evolutionary law. Evolutionary Theory 1:1-33. VOELKER, G., S. ROHWER, R. C. K. BOWIE, AND D. C. OUTLAW. 2007. Molecular systematics of a speciose, cosmopolitan songbird genus: Defining the limits of, and relationships among, the Turdus thrushes. Molecular Phylogene tics and Evolution 42:422-434. WALLACE, A. R. 1881. Island Life. Macmillan, London, UK.

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BIOGRAPHICAL SKETCH Natalie Wright graduated valedictorian from Ridgeview High School, Orange Park, Forida, in 2001. She received a bachelors of science degree from the University of Florida in 2005, majoring in zoology with a minor in English. During her time as a grad uate student at the University of Florida, Natalie has taught nine semesters, including verteb rate zoology, functional vertebrate anatomy, and avian biology laboratorie s. Her dedication as a teaching assistant was recognized with the University of Florida Graduate Student Teaching Award in Spring 2009. Natalie has years of experience with a variety of museum research and collections management duties, including excavating and preparing fossi ls, maintaining a beetle colony for skeletal specimen preparation, and preparing over 650 bird specimens. She has studied the evolution, ecology, and conservation of modern and extinct birds in Florida, Kentucky, the U.S. Virgin Islands, the Bahamas, and Trinidad and Tobago. 63