|
FINAL REPORT
TECHNICAL REPORT NO. 25
STATUS SURVEY OF SEVEN FLORIDA MAMMALS
by
Stephen R. Humphrey,
William H. Kern, Jr.,
and Mark S. Ludlow
Florida State Museum
University of Florida
Gainesville FL 32611
Supported by:
Jacksonville Endangered Species Office
U.S. Fish and Wildlife Service
2747 Art Museum Drive
Jacksonville FL 32207
through the
Florida Cooperative Fish and Wildlife Research Unit
117 Newins-Ziegler Hall
University of Florida
Gainesville FL 32611
Research Work Order No. 37
June 15, 1987
_____ __~__l~~s~
TABLE OF CONTENTS
Introduction ......................................... ..... ..............................................................
Acknowledgments ..................................................................................................... ..... 1
Beach cottontail rabbit (Sylvilagus floridanus ammophilus)................................................. 3
Seashore cotton rat (Sigmodon hispidus littoralis)............................................................8
Southeastern beach mouse (Peromyscus polionotus niveiventris)........................................ 13
Goff's pocket gopher (Geomys pinetis goffi).................................................................... 18
Anastasia Island mole (Scalopus aquaticus anastasae)...................................................... 20
Anastasia Island cotton mouse (Peromyscus gossypinus anastasae)...................................23
Anastasia Island beach mouse (Peromyscus polionotus phasma)..................................... 29
Conclusions........................................................................................................................... 34
Literature Cited.................................................................................................................. 38
STATUS SURVEY OF SEVEN FLORIDA MAMMALS
Introduction
The purpose of this project is to determine the status of seven subspecies of
Florida mammals that are known to occur only on barrier islands, barrier beaches, or
other isolated areas on the east coast of Florida. The seven mammals are the beach
cottontail rabbit (Sylvilagus floridanus ammophilus), the seashore cotton rat (Sigmodon
hispidus littoralis), the southeastern beach mouse (Peromyscus polionotus niveiventris),
Goff's pocket gopher (Geomys pinetis goffi), the Anastasia Island mole (Scalopus
aquaticus anastasae), the Anastasia Island cotton mouse (Peromyscus gossypinus
anastasae), and the Anastasia Island beach mouse (Peromyscus polionotus phasma).
The areas where these animals occur have undergone rapid residential and
commercial development, and it is possible that one or more subspecies might be
threatened with extinction. All seven animals are formally under review (U.S. Fish and
Wildlife Service 1985). Current information on the status of these taxa would be useful
to the U.S. Fish and Wildlife Service in deciding whether any of them should be listed
under the Endangered Species Act. The primary objective of this study was to
determine the current survival status, geographical distribution, and nature of the habitat
occupied by these seven subspecies of Florida mammals. An additional objective was to
report on the taxonomy of the subspecies, document sampling effort and success and
summarize information on population abundance and distribution, describe the occupied
habitat, and evaluate threats to survival of the existing populations.
Acknowledgments
This study was made possible by the leadership of David Wesley, Michael
Bentzien, and John Paradiso of the U.S. Fish and Wildlife Service, the facilitation of
Franklin Percival of the Florida Cooperative Fish and Wildlife Research Unit, and the
cooperation of Don Wood of the Florida Game and Fresh Water Fish Commission and
2
Edwin Conklin and James Stevenson of the Florida Department of Natural Resources.
We appreciate the interest and cooperation of numerous individuals in the field,
including Judy Lamia, for help with field work; Steven Vehrs, Merritt Island National
Wildlife Refuge; Lt. Col. Wayne K. Penley, Cape Canaveral Air Force Station; and the
managers and staff of Anastasia State Recreation Area, Fort Matanzas National
Monument, and Sebastian Inlet State Recreation Area.
Beach cottontail rabbit (Sylvilagus floridanus ammophilus)
Background.--The beach cottontail rabbit (Sylvilagus floridanus ammophilus) was
described by A. H. Howell (1939). It is known only from the type locality, "Oak
Lodge," on the East Peninsula opposite Micco, Brevard Co., Florida. This site was the
residence of Mr. C. F. Latham when collecting was done in the 1880s and 1890s; habitats
there were described by Chapman (1889a). Now it is in the town of Floridana Beach.
The area has been heavily developed in recent years. Though the common name "Micco
cottontail" has been applied to this subspecies, this is a poor choice because Micco is not
on the barrier island of interest and is the type locality (the Sebastian River near Micco)
of a mainland subspecies of cottontail.
Methods.--The distribution of cottontail rabbits was documented by driving along
roads at night and spotting them with auto headlights and hand-held spotlights. Starting
time ranged from 2000 to 2200 hrs, and surveys always ended before 2400 hrs.
Results.--Road searches for cottontails are summarized in Table 1. Other
observations follow. A cottontail was found dead on the road on 4 July 1986 about 30
meters inside the front gate of Cape Canaveral Air Force Station (SW 1/4 of Sec. 12, T
23 S, R 37 E). Two cottontails were seen while checking the trapline at site MI-6 on 9
July 1986. Rabbit tracks occurred on the beach and rabbit scat was common in nearby
palmetto scrub at site MI-9, Indian Harbor Beach east of AIA on 16 July 1986. Two
cottontails were seen on 23 July 1986 at the sewage treatment plant near site MI-12, just
north of Sebastian Inlet. Other mammals noted during night driving were opossums,
armadillos, marsh rabbits, a red fox, raccoons, a bobcat, white-tailed deer, and feral
pigs.
Additionally, a cottontail presumed to be of another subspecies was seen in a
recently burned area south of the boardwalk at Turtle Trail Beach (site IR-2), Indian
River Co., on 30 July 1986. Sebastian Inlet separates this population from the barrier
island from which S. f. ammophilus was described. Cottontails of uncertain subspecific
Table 1. Observations of beach cottontail rabbits (Sylvilagus floridanus ammophilus) on
Merritt Island and the Canaveral Peninsula, including its northward extension and its
southward extension (Eau Gallie Beach = East Peninsula).
Road length
(km)
Date
Number of
individuals
Location
2 July 1986
8 July 1986
8 July
8 July
9 July
1986
1986
1986
9 July 1986
9 July 1986
9 July 1986
9 July 1986
10 July 1986
10 July
10 July
10 July
10 July
10 July
10 July
17 July
17 July
1986
1986
1986
1986
1986
1986
1986
1986
4.7 KSC, beach road from Pad A to Pad B
10.3 KSC, AIA beach road from SR 402 to
Air Force/NASA boundary
1.8 KSC, side road west of AIA
6.4 Saturn Causeway from A1A to Kennedy Parkway
4.8 Heavy Launch Road, from Central Control
Road to Cape Road
0.3 CCAFS, Cape Road southwest from Heavy
Launch Road
2.1 ICBM Road, from Heavy Launch Road to
Cape Road
6.4 Central Control Road and Lighthouse Road,
from Security Office to Road Block 7
1.3 Camera Road, from Lighthouse Road to beach
13.7 KSC, Kennedy Parkway southbound, from NASA
Security Gate 4 to NASA Parkway
KSC, Schwartz Road and road to dump
KSC, Static Test Road
13.7 Kennedy Parkway northbound, from NASA
Parkway to Security Gate 4
NASA Causeway
7.2 MINWR, SR 402 to Playalinda Beach
7.2 CNS, Canaveral Beach Road from Security
Gate 4 to Camera Pad 10
7.1 KSC, TEL-4 Road, Kennedy Parkway to KARS
4.0 KSC, Kennedy Parkway southbound, from
TEL-4 Road to NASA Parkway
17 July 1986 2.4 Jerome Road east of Kennedy Parkway 0
17 July 1986 1.9 Ransom Road east of Kennedy Parkway 0
18 July 1986 7.2 Canaveral National Seashore 1
designation also were common on Anastasia Island, St. Johns Co., which is separated
from the New Smyrna Beach extension of the Canaveral Peninsula by Matanzas Inlet.
Taxonomy.--Bangs (1898) referred cottontails from Oak Lodge to Lepus
sylvaticus sylvaticus (= Sylvilagus floridanus mallurus). Allen (1890) named mainland
cottontails from near Micco, Sebastian River, Brevard Co., as Lepus sylvaticus floridanus
(= Sylvilagus floridanus floridanus). Nelson (1909) assigned all Florida specimens to
these two subspecies. On the basis of 8 specimens from Oak Lodge, Howell designated
S. f. ammophilus as slightly paler in color of the upper parts, sides, head, ears, and
nucchal patch than S. f. floridanus, which occurs on most of the Florida mainland south
of St. Augustine, St. Johns Co., and Blitches Ferry, Citrus Co. (Schwartz 1956). Howell
found ammophilus to be similar in skull measurements to floridanus, except that the
auditory bullae of ammophilus averaged smaller. In a quantitative comparison of Florida
subspecies, Schwartz (1956) chose to retain ammophilus, and he described a new
subspecies, S. f. paulsoni, from the coastal ridge of Palm Beach and Dade Counties. He
judged that the four Florida subspecies were distinguishable on the basis of both color
and skull measurements. He referred a single specimen from Merritt Island to
floridanus rather than ammophilus.
When Howell (1939) described the beach cottontail (S. f. ammophilus), he did not
attempt a review of geographic variation of the species, on which any taxonomic
arrangement should be based. Schwartz (1956) undertook such a review, but his
interpretation assumes geographic discontinuities in size. He stated that Atlantic coastal
populations (ammophilus, paulsoni) are discontinuously paler than the mainland
populations (mallurus, floridanus), and he showed that means of some measurements
differ among the named subspecies. An alternative interpretation is that size diminishes
clinally southward and toward the Atlantic coast. Schwartz considered ammophilus and
paulsoni to be convergently pale in adaptation to light-colored coastal soils. Still lacking
is a test of what is now the current a priori taxonomic grouping against clusters of
specimens defined by statistical similarity. The best interpretation of the differences
Howell noted will be debatable until such a comparison is made. Until then, the
conservative tradition of taxonomy directs that the existing taxonomic arrangement be
used.
Based on the taxonomic work to date, for purposes of this study we assumed that
any cottontail on Canaveral Peninsula was referable to the beach subspecies. We
assumed that any cottontail observed on Merritt Island or on the barrier island south of
Sebastian Inlet was referable to S. f. floridanus. The northern end of Merritt Island
actually has narrow connections to both the mainland and Canaveral Peninsula. The
unsatisfactory nature of these assumptions shows why more rigorous study is needed.
Distribution and Habitat.--Habitat includes dune grassland, palmetto scrub,
highway right-of-ways, and off-road access trails on government property.
Excellent, extensive habitat for cottontails occurs on the Canaveral Peninsula
north toward New Smyrna Beach and south to Port Canaveral (including Canaveral
National Seashore, Cape Canaveral Air Force Station, and part of Kennedy Space
Center). However, which subspecies occupies this area is debatable. The northern part
of East Peninsula, south through Melbourne Beach, is heavily developed and retains little
cottontail habitat. South of Melbourne Beach, much good cottontail habitat remains.
Most suburban development here is single-family dwellings with yards and often with
remnants of native vegetation, and at least five parcels are in public ownership (Spessard
Holland Park, Sebastian Inlet State Park, and three tracts purchased in 1986 .from the
Disney Corporation by Brevard County).
7
Survival Status.--Pending a better definition of the distribution of this
subspecies, its survival appears to be secured by the substantial amount of habitat
protected from development by public ownership.
Management.--No management issues are apparent at present.
Research Needs.--A review of geographic variation in Florida cottontails is
needed, in which the current a priori taxonomic grouping is compared with clusters of
specimens defined by statistical similarity. Whether or not the taxonomic arrangement is
changed as a result, this analysis is necessary to ascertain the actual distribution of the
beach subspecies.
Seashore cotton rat (Sigmodon hispidus littoralis)
Background.--The seashore cotton rat (Sigmodon hispidus littoralis) was
described by Chapman (1889b). It is known only from the type locality, on the East
Peninsula, opposite Micco, Brevard Co., Florida. Collecting in February and March
1889, Chapman stayed at Oak Lodge, the residence of C. F. Latham, which is now the
site of Floridana Beach. This barrier island has been undergoing rapid development in
recent years. The subspecies has been termed the "Micco cotton rat", but this name is
confusing because Micco is on the mainland and may be occupied by S. h. floridanus
(though Bangs included Micco specimens in littoralis).
Methods.--Sampling was conducted on Merritt Island, the Canaveral Peninsula,
and East Peninsula on 2-25 July 1986 (Figure 1). Sites MI-I, 2, and 3 were located on
Cape Kennedy Air Force Station. Sites MI-4, 5, 6, 7, 10, and 11 were located on
Kennedy Space Center. Sites MI-12 and MI-13 were in the northern portion of
Sebastian Inlet State Recreation Area. We think but are not certain that Sites MI-14, 15,
and 16 were located on Disney Corporation properties purchased in late 1986 by Brevard
County as park land. Trapping was done with lines of 40 large Sherman traps baited
with rolled oats. To prevent mortality and saturation of traps by cotton rats, which are
active at all times of day, traps were set in the late afternoon and checked and closed in
the morning. Traplines were run for 1 to 3 nights.
Results.--The results of trapping in coastal Brevard Co. are listed in Table 2.
Sigmodon were widespread and abundant.
Taxonomy.--Though the geographic variation of species of Sigmodon has
received much attention (Baker 1969, Dalby and Lillevik 1969, Zimmerman 1970), that
of subspecies of S. hispidus has not. A total of six subspecies is recognized for Florida
alone. All were named before the days of rigorous statistical comparison, and most were
distinguished only on the basis of color. As a result, the current taxonomic
Figure 1. Locations of sampling sites on Merritt Island, the
Peninsula, and southward to Sebastian Inlet.
S MI-14
FLORIDANA
BEACH
ICCO MI-13
MI-12
SEBASTIAN INLET
Canaveral Peninsula, East
codoo66dooo6omo
0L.
r-l O
000000000000-^00
0000000000000 00N
OatC> -0a C oo Coo0 a
OObObOOOO-rOOOOO ej
C0<0-^-0000000000
oooooo>oorTooooo >
000000100000 000
u(D C)> r C> V r ar a, CD a M
0- -- co f^&- o v>
c o -- -
- ITinr-- ------- 0
0..( 04 04 0-4 0
^ *0
?s.
:ag
0C
1
s
U
0, bo
cn
0
4)4
S s
.2 Q4
.o pC S
< .b 5
t>C
S^
c55
arrangement is a mess, and there is little basis for confidence in the validity of S. h.
littoralis.
For purposes of this study we assumed that specimens from East Peninsula, the
Canaveral Peninsula, and Merritt Island all are referable to littoralis. Other subspecies
from the coast or islands of Florida include insulicola, from Sanibel, Captiva, and Pine
Islands, Manasota Key, and the adjacent mainland, described by Howell (1943);
spadicipygus, from Cape Sable, described by Bangs (1898); and exsputus, from the
Lower Keys, described by Allen (1920). In littoralis, spadicipygus, and insulicola,
intergradation with mainland forms was noted in the original descriptions. While
intergradation of recognizable forms in zones of contact is consistent with the subspecies
concept, there is much disagreement among authors as to the location of the zones of
intergradation of spadicipygus with adjacent subspecies, as noted by Layne (1974). The
taxonomic status of numerous other island populations of S. hispidus in Florida is
unknown, such as from the barrier islands of Indian River and St. Lucie Counties (Table
3). The comments of Bangs (1898) regarding cotton rats from the Georgia Sea Islands
are revealing: "The cotton rat upon Ossabaw Island is very pallid, and has a strong
tendency to have pale cinnamon under parts. Were it not for the great local variation in
color presented by this species, I should feel tempted to recognize this form by name."
Two inferences from these comments are worthwhile. First, the great local variation in
color needs to be considered in a comprehensive review of geographic variation in cotton
rats of Florida. Second, the possibility should be considered (as Schwartz concluded in
the case of cottontails, above) that the many isolated and relatively unrelated populations
of cotton rats on coastal islands and barrier beaches convergently have acquired pale
color in adaptation to the pale substrate; in this case, application of subspecies names is
a dubious exercise.
Distribution and Habitat.--Because the subspecific taxonomy of hispid cotton rats
is so poorly known, there is no objective basis to judge the distribution of S. h.
littoralis. Technically this form is known only from the type locality. The population
also "probably occurs some distance north and south thereof on the coastal beach" (Hall
1981). Chapman evidently had a much wider distribution in mind; he speculated that
the subspecies occurred on "the coasts of Southern Florida," and and discussed the color
of "an example of littoralis from Pine Island, in Charlotte Harbor" (off the Gulf coast,
Lee Co.). Citing specimens ranging from Miami (Dade Co.) to Anastasia Island (St.
Johns Co.), Bangs (1889) stated the range of littoralis as "from about Miami north to
northeastern Florida." Dalby and Lillevik (1969) referred their only Florida specimen,
from Boca Raton (Palm Beach Co.), to littoralis. The records of S. hispidus in Table 3
presumably would have been referred to littoralis by Chapman and Bangs, even though
their ranges are separated from East Peninsula by water gaps. Howell (unpublished) was
of the opinion that littoralis was confined to East Peninsula, but his comparisons were
no better than earlier ones.
Survival Status.--Even if future study of geographic variation shows S. h.
littoralis to be a valid subspecies occurring only on East Peninsula, the population
probably can survive indefinitely. Available habitat includes the strip of dune grassland
and palmetto scrub along the ocean, strips of right-of-way grassland along US AIA and
other roads, and at least six parcels of public land (Patrick Air Force Base Missile Test
Center, Spessard Holland Park, Sebastian Inlet State Park, and three tracts purchased in
1986 from the Disney Corporation by Brevard County.
Management.--Only if littoralis proves to be a valid subspecies confined to East
Peninsula might management become an important issue. In that event, the public land
probably would support an aggregate population of a few thousand animals. One
management practice then needing attention would be the frequency and timing of
mowing highway right-of-ways (Wilkins and Schmidly 1980).
Research Needs.--See Taxonomy.
Southeastern beach mouse (Peromyscus polionotus niveiventris)
Background.--The southeastern beach mouse (Peromyscus polionotus niveiventris)
was described by Chapman (1889c). It occurs on the sand dunes along the beach from
Ponce (Mosquito) Inlet south to Hollywood Beach. Bangs (1898) found it to be
"extremely abundant on all the beaches of the east peninsula from Palm Beach at least to
Mosquito [Ponce] Inlet", and Howell (unpublished manuscript) found that it was
abundant in the 1930s. I. J. Stout (personal communication) also found it to be abundant
in the middle and late 1970s on Cape Canaveral. Most other populations had
disappeared by the early 1970s (M. H. Smith, personal communication).
Methods.--Sampling was conducted on the Canaveral Peninsula and East
Peninsula on 2-25 July 1986 (Figure 1). Sites MI-1, 2, 4, 6, 8, 9, 12, 13, 14, 15, and 16
were in habitat suitable for beach mice. Sampling was conducted on the barrier islands
from Sebastian Inlet to Hutchinson Island from 30 July to 1 August 1986. Site IR-1 was
located in the southern portion of Sebastian Inlet State Recreation Area. Site IR-2 was
located at Turtle Trail Public Beach Access. Site SL-2 was located in Pepper Park. Site
HI-1 was located in Surfside Beach Park. Trapping was done with lines of 40 large
Sherman traps baited with rolled oats. To prevent mortality and saturation of traps by
cotton rats, which are active at all times of day, traps were set in the late afternoon and
checked and closed in the morning. Traplines were run for 1 to 3 nights.
Results.--Southeastern beach mice were captured in Canaveral National Seashore,
Cape Kennedy Air Force Station, the southern half of Sebastian Inlet State Recreation
Area, Turtle Trail Public Beach Access, and Pepper Park (Tables 2 and 3, Figure 1). No
beach mice were captured on East Peninsula, including the northern half of Sebastian
Inlet State Recreation Area.
Table 3. Rodents captured from Sebastian Inlet to Hutchinson Island (Indian River and
St. Lucie counties), 30 July to 1 August 1986.
Adjusted
trap Peromyscus Peromyscus Sigmodon Trap
Site nights gossypinus polionotus hispidus success
IR-1 69 4 2 10 0.232
IR-2 113.5 3 3 10 0.141
SL-1 76.5 0 0 0 0.0
SL-2 107.5 0 1 0 0.009
SL-3 79 0 0 11 0.139
HI-1 78.5 0 0 0 0.0
Total 524 7 6 31 0.084
Taxonomy.--Chapman (1889) named the southeastern beach mouse as Hesperomys
niveiventris, from the East Peninsula, opposite Micco, Brevard Co., Florida. Elsewhere
he describes doing this field work at Oak Lodge, the residence of C. F. Latham. Bangs
(1896) applied the name Peromyscus polionotus to the beach and oldfield mice, and
Osgood (1909) referred the southeastern population to subspecies niveiventris. This
taxonomic arrangement has not been reviewed since then; Bowen (1968) dealt only with
Gulf coastal subspecies of P. polionotus.
Osgood pointed out that niveiventris shared the unusual character of venter hair
being white from tips to roots with a small group of Peromyscus: P. p. phasma, rhoadsi,
and albifrons; and P. leucopus ammodytes, which occupies the coastal grassland of
Monomoy Island, Massachusetts. Osgood noted niveiventris to be intermediate in
paleness between the subspecies polionotus and phasma. Bowen discussed the color of
ventral hair in some other coastal subspecies of P. polionotus.
Distribution and Habitat.--The many subspecies of P. polionotus occupy either
mainland oldfields or coastal dunes. The latter "beach" mice are restricted to sand dunes
vegetated mainly by sea oats (Uniola paniculata) and dune panic grass (Paspalum
amarulum), and to the adjoining scrub, characterized by oaks (Quercus sp.) and sand
pine (Pinus clausa) or palmetto (Serenoa repens).
Nowhere in the range of beach mice is more extensive open scrub adjacent to
dune grassland occupied by beach mice than on Merritt Island. Here Extine and Stout
(1987) documented a reciprocal, shifting habitat preference of P. p. niveiventris for
patchy and dense palmetto scrub relative to dune grassland habitat, especially during
stable low population density and during exponential population growth. This
preference was least strong during peak and declining population density. This result
indicates that juxtaposition of coastal scrub and dune grassland provides much better
habitat for beach mice than does the grassland alone. The scrub here includes sea grape
(Coccoloba uvifera) and wax myrtle (Myrica cerifera) as co-dominant plants; their mast
may diversify food resources for rodents considerably. In support of this notion, it is
worth remembering the abundance of oldfield mice in early seral stages of scrub in the
Ocala National Forest.
The dune grassland at Cape Canaveral is excellent, extensive habitat for beach
mice, and the high numbers captured there (Sites MI-I, 2) reflected a high-density
population. Northward, the habitat narrows to a single dune in Canaveral National
Seashore, where population density appears to be lower (Sites MI-4, 6). Sites selected on
East Peninsula and the barrier islands from Sebastian Inlet to Hutchinson Island were the
only substantial and accessible tracts of dune grassland. The results suggest that beach
mice no longer occur in the severely fragmented habitat along East Peninsula. The
sampling from Sebastian Inlet south to Hutchinson Island suggest that only a few, small,
fragmented populations of beach mice remain there. The southern part of the historic
range includes Jupiter Island, Palm Beach, Lake Worth, Hillsboro Inlet, and Hollywood
Beach (Bangs 1889, Osgood 1909, Howell unpublished). The southernmost recent record
evidently is from Hutchinson Island in 1969 (Sealander et al. 1971).
Survival Status.--The southeastern beach mouse should be able to survive
indefinitely on Cape Kennedy Air Force Station. The same may be true at Canaveral
National Seashore, though beach erosion there may become a threat. The status of
populations to the south is more tenuous, although they may continue to persist in the
southern half of Sebastian Inlet State Recreation Area and Pepper Park.
We found no evidence of house mice (Mus musculus) colonizing beach mouse
habitat, but activity of house cats (Felis cattus) was widespread. The effect of these two
exotic species on survival of beach mouse populations is speculative but may be quite
important (Humphrey and Barbour 1981). Either a competitor or a predator alone can
eliminate another species, and the effects of a competitor and a predator together would
be additive. The two processes operate differently--predation stimulates reproduction of
most prey species, whereas competition suppresses reproduction of most species. Perhaps
the threat of house mice has not materialized because management of these public lands
does not promote refuse from intensive recreational uses.
Management.--Because the only populations of beach mice with any chance of
survival are those on public land, management should focus on habitat acquisition and
management. The apparent absence of beach mice from the northern portion of
Sebastian Inlet State Recreation Area suggests that the local population could be enlarged
considerably by introduction from the southern portion.
Management of existing public land for populations of southeastern beach mice
should focus on minimizing changes in the habitat of dune grassland that would favor
survival of house mice. Because house mice now are absent from these tracts, the thrust
of this management should be to avoid changes in public use that would establish points
of introduction or refuge for house mice or that would increase the amount of garbage
available to colonizing house mice as food. All facilities supporting visitors to public
lands should be located in habitats inland of the dune grassland. Routine, intensive
rodent control at park and concession buildings, and frequent and thorough refuse
removal practices could be helpful. Control of free-ranging house cats could be helpful.
Plans to substantially expand concessionaire operations at Sebastian Inlet State
Recreation Area (Orlando Sentinal, January 29, 1987, page D-12) should be examined
carefully for potential impacts on the beach mouse population there.
Research Needs.--It would be useful to monitor the populations at Sebastian Inlet
State Recreation Area and Pepper Park. Additional survey work is needed in the few
remaining patches of habitat south of Hutchinson Island.
Basic research is needed to determine whether competition really occurs between
beach mice and house mice, and if so, on how strong it is. Comparable research is
needed to determine whether predation by house cats affects beach mice. Applied
research is needed on how park management practices affect house mice and house cats.
Goff's pocket gopher (Geomys pinetis goffi)
Background.--Goff's pocket gopher (Geomys pinetis goffi) was described by
Sherman (1944). It is known only from the type locality at Eau Gallie, Brevard Co., on
a strip of fine sands between the Indian and St. Johns rivers. Humphrey (1981)
presented substantial evidence that this subspecies has become extinct. However, like
any other null hypothesis, extinction can be disproven but never proven. Additional
surveys offer the hope that that conclusion may be refuted.
Methods.--Pocket gophers were sought by looking for mounds of soil (burrow
castings). Reconnaissance was done only from major roads through the area originally
described. This search was cursory compared with the exhaustive effort by Humphrey
(1981). However, the new search was done at a different time of year--July instead of
October to March.
Results.--No evidence of pocket gophers was found.
Taxonomy.--G. p. goffi is known from 22 specimens taken between 1897 and
1955. It was described by Sherman (1944) on the basis of a longer body than in other
Florida pocket gophers. This difference he attributed to the occurrence of an extra
body segment, reflected by 13 pairs of ribs instead of the usual 12.
Distribution and Habitat.--All records of G. p. goffi are from the type locality of
Eau Gallie, described as "... part of a strip of Norfolk and St. Lucie fine sands which
border the Indian River. Evidence of Geomys has been found for a distance of about
two miles both north and south of Eau Gallie and for a distance of about two miles
inland from the Indian River." This soil is distributed as a long, narrow landform, the
Pineda Ridge, which extends from north of Bonaventure through the city of Melbourne
and south to Malabar. The town of Eau Gallie has been subsumed as part of the city of
Melbourne, and most of the area within a 2-mile radius of the old town is urban or
suburban habitat. A substantial amount of suitable habitat occurs on roadsides, railroad
right-of-way, a few pastures, fields along airport runways, parks, golf courses, baseball
fields, and cemeteries. In the immediate area of Eau Gallie, the best habitat occurs on
the fenced grounds of Melbourne Regional Airport; the rest is in golf courses,
cemeteries, and other areas where gophers are likely to have been actively exterminated.
Some native habitat also persists in the extremities of the Pineda Ridge, but it has been
so long protected from fire that the vegetation forms an extremely dense understory and
(in the case of sand pine scrub) a closed tree canopy.
Survival Status.--All recent evidence suggests that Goff's pocket gopher is
extinct.
Management.--Not applicable.
Research Needs.--None.
Anastasia Island mole (Scalopus aquaticus anastasae)
Background.--The Anastasia Island mole (Scalopus aquaticus anastasae) was
described by Bangs (1898). It was abundant at the type locality: Point Romo, Anastasia
Island, St. Johns Co. Anastasia Island has been subjected to rapid development.
Methods.--Moles were sought by on-foot searches for soil-surface traces of
subsurface tunnels. The number of tunnels was counted while setting and checking
traplines established for catching other small mammals.
Results.--The number and location of mole tunnels observed on Anastasia Island
are given in Table 4 and Figure 2. Moles were widespread, and the number of tunnels
indicates that animals are common. Interviews with residents of the island indicated that
moles were abundant in lawns.
Taxonomy.--The Anastasia Island mole was named Scalops anastasae by Bangs
(1898) on the basis of fur color and cranial characteristics. It was referred to Scalopus
aquaticus anastasae by Jackson (1915). Based on a review of geographic variation in
morphology, Yates (1978) synonomized S. a. anastasae (and S. a. howelli) with S. a.
australis, with a combined range of most of peninsular Florida and the southeastern
United States. Yates did not evaluate fur color, which fades in old museum specimens.
Distribution and Habitat.--Moles occurred in all habitats sampled, including dune
grassland, palmetto scrub, wax myrtle thicket, xeric oak forest, and mesic oak forest, as
well as habitats not formally sampled, such as lawns. Distribution is essentially
throughout Anastasia Island.
Survival Status.--No threats to the survival of the Anastasia Island mole were
identified, and its status appears to be secure.
Management.--None needed.
Research Needs.--None needed.
~s ___s~l_
SJ-8
SJ-9
0
L-SJ-3 0
-SJ-4
"'SJ-6 6
SJ-5
.\ ST. AUGUSTINE INLET
AI-15,17-
AI-9
-N-
0 2 4 MILES
18
AI-3
Al-1,2
SJ-2
RI-1
AI-4
AI-5
Figure 2. Locations of sampling sites on Anastasia Island and northward in St. Johns
Co., Florida.
AI-8,1
AI-7,1
ML-1
1,16
2
Mole tunnels counted on Anastasia Island and vicinity, 22 May to 12 June
Estimated length
of transect (m)
Number of mole
tunnels counted
400
400
400
400
600
600
200
100
100
260
400
600
200
200
400
200
400
400
750
200
300
600
200
Total 8,410 37
Table 4.
1986.
Site
CI-I
CI-2
CI-3
CI-4
AI-I
AI-2
AI-3
AI-4
AI-5
AI-6
AI-7
AI-8
AI-9
AI-10
AI-11
AI-12
AI-13
AI-14
AI-15
AI-16
AI-17
RI-1
ML-1
Anastasia Island cotton mouse (Peromyscus gossypinus anastasae)
Background.--The Anastasia Island cotton mouse (Peromyscus gossypinus
anastasae) was described by Bangs (1898). The type locality is Point Romo, Anastasia
Island, St. Johns Co. Animals were not common, and Bangs took only nine individuals.
Elliot (1901, cited in Porunelle and Barrington 1953) reported ten specimens taken at
"Espanita", the home of a Mr. Middleton, located 2-3 miles (presumably north) from the
type locality. Apparently this mouse has not been collected on Anastasia Island since
then; Pournelle and Barrington (1953) failed to catch any in 306 trapnights in 1948, even
though the purpose of their trip was to obtain topotypes. These authors cited
development by man as the probable cause of the scarcity or absence of cotton mice at
Anastasia Island. Osgood (1909) extended the range north to Cumberland Island,
Georgia. On this basis, the subspecies could be expected to occur on the intervening
barrier islands and beaches. Most of this area is being developed rapidly for residential
and commercial uses.
Methods.--Sampling was conducted on Anastasia Island and vicinity from 22
May to 12 June 1986 (Figure 2). Sites AI-9, 10, 13, 14, 15, and 17 were within
Anastasia State Recreation Area. Sites AI-7, 8, 11, 12, and 16 and Site RI-1 were
within Fort Matanzas National Monument. Sites CI-2; AI-I, 4, 5, 6, 7, 12, 13, and 14;
RI-l; and ML-I were in dune grassland habitat judged suitable for beach mice. Sites
CI-1, 3, and 4 and AI-3, 8, 9, 10, 11, 15, 16, and 17 were in wax myrtle, palmetto,
xeric oak, or mesic oak habitats judged suitable for cotton mice. Cotton mice also
would be expected occasionally in beach mouse habitat. Site AI-2 was in dense grass
judged suitable only for cotton rats. Sampling was conducted on the barrier beach from
Vilano Beach northward from 12-20 June 1986. Sites SJ-3 to 9 were located in Guana
River Wildlife Management Area. Sites SJ-3, 5, 6, and 8 were in habitat suitable for
beach mice, and Sites SJ-4, 7, and 9 were in habitat suitable for cotton mice. Trapping
was done with lines of 40 large Sherman traps baited with rolled oats. To prevent
Table 5. Rodents captured on Anastasia Island, nearby Conch and Rattlesnake Islands,
and vicinity, 22 May to 12 June 1986.
Peromyscus
gossypinus
Peromyscus
polionotus
Sigmodon Mus Rattus
hispidus musculus rattus
64 54 13
Adjusted
trap
nights
Site
CI-1
CI-2
CI-3
CI-4
AI-1
AI-2
AI-3
AI-4
AI-5
AI-6
AI-7
AI-8
AI-9
AI-10
AI-11
AI-12
AI-13
AI-14
AI-15
AI-16
AI-17
AI-18
RI-I
ML-1
SJ-1
SJ-2
79
76.5
79
80
120
120
90
20
100
121.5
118
108
79
73
69.5
79
80
69.5
150
34.5
38.5
38
118
39
60
38.5
Trap
success
0.076
0.131
0.0
0.0
0.042
0.108
0.011
0.0
0.050
0.025
0.144
0.102
0.0
0.0
0.187
0.127
0.275
0.144
0.040
0.290
0.026
0.0
0.017
0.051
0.017
0.0
__~___il_~____l______
Total 2,078.5 0
17 0.071
mortality and saturation of traps by cotton rats, which are active at all times of day,
traps were set in the late afternoon and checked and closed in the morning. Traplines
were run for 1 to 3 nights.
Results.--We captured no cotton mice on Anastasia Island in over 2,000
trapnights of sampling (Table 5). Additionally, Joshua Laerm (personal communication)
failed to find this animal in approximately 5,000 trapnights on Anastasia Island in the
early 1980s. Our specimens of P. gossypinus from the barrier beach north of Vilano
Beach (Table 6) were dark in color and not referable to the subspecies anastasae.
Taxonomy.--The Anastasia Island cotton mouse was named as Peromyscus
anastasae by Bangs (1898) and assigned to Peromyscus gossypinus anastasae by Osgood
(1909). Osgood also included in P. g. anastasae populations from Cumberland Island,
Camden Co., Georgia, which had been named as P. insulanus by Bangs (1898). This
implied a much larger range, including a great length of coast not separate from the
mainland, and including areas separated from one another by the St. Johns and St. Marys
Rivers and other water barriers. This situation is contrary to common sense. As
suggested above for cottontails and cotton rats, such an arrangement may represent the
lumping of relatively unrelated populations that are convergent in color, in adaptation to
the light color of coastal soils.
Osgood referred only 18 specimens from Anastasia Island and 36 from
Cumberland Island to anastasae. However, he examined P. gossypinus from other
nearby areas, including St. Marys, Georgia; Amelia Island; Burnside Beach [on the coast
of Duval Co. north of Anastasia Island]; Carterville [on the mainland west of Anastasia
Island]; and Summer Haven [formerly El Penon island, now the point south of Matanzas
Inlet--see next paragraph]. Osgood's remarks about anastasae offer perspective on the
validity of the taxon: "Although the pale forms from Anastasia and Cumberland islands,
respectively, are entirely isolated from each other and from the mainland forms, they
seem to be absolutely alike and also are not different from certain aberrant
Table 6. Rodents captured in St. Johns County from Vilano Beach north, 12-20 June
1986.
Adjusted
trap Peromyscus Ochrotomys Sigmodon Mus Rattus Trap
Site nights gossypinus nuttalli hispidus musculus rattus success
SJ-3 40 0 0 0 1 0 0.025
SJ-4 34.5 0 0 6 0 0 0.174
SJ-5 119 0 0 5 1 0 0.050
SJ-6 116.5 0 0 9 1 0 0.086
SJ-7 115 0 0 5 0 3 0.070
SJ-8 78 1 0 9 1 0 0.141
SJ-9 72 7 1 2 0 3 0.181
Total 575 8 1 31 4 6 0.087
(intermediate?) specimens from the mainland. Moreover, the mainland specimens most
similar to them are not from localities immediately adjacent to the islands in question,
specimens from St. Marys, Ga., Burnside Beach, Fla., etc., being typical gossypinus."
Further doubt about this arrangement is cast by Osgood's remarks under P. g. palmarius:
"The type of palmarius and a very small percentage of the large series of topotypes are
unusually pale and scarcely distinguishable from comparable specimens of anastasae...
the great preponderance of dark specimens from the type locality [Oak Lodge] tends to
indicate that the type is probably an aberrant specimen rather than the representative of
a well-defined form. The case might be construed also to the effect that pale coast
forms are undergoing parallel differentiation at several points and that the same
character (paleness) has been established independently on Anastasia and Cumberland
islands and is only in its incipiency on the peninsula opposite Micco."
It is clear from Bangs' text that he was indeed on Anastasia Island, but confusion
arises because the type locality is listed as "Point Romo, Anastasia Island." Point Romo
is no longer in use as a place name, but an old map in the files of St. Augustine
National Monument shows Point Romo to be on the south edge of Matanzas Inlet, rather
than the north. This appears to conflict with Bangs' usage (in his account of Peromyscus
niveiventris) of the name "Point Matanzas" for the south edge of Matanzas Inlet.
Matanzas Inlet and the adjoining land was reconfigured by the U.S. Army Corps of
Engineers in the 1930s, when the Intracoastal Waterway was built. Before then, the inlet
had two channels, which went around an island with the Spanish name "El Penon."
According to the historian at St. Augustine National Monument, El Penon was a rocky
point used as a navigation marker. This island was joined to Point Romo by the Corps
of Engineers. As a result, the island is now the point south of Matanzas Inlet. Now this
is the site of the current settlement of Summer Haven. The former Point Romo is part
of the barrier beach between Summer Haven and Marineland. We infer that either (1)
the original Spanish maps were mislabeled, (2) Bangs was mistaken about which point
was Point Romo, or (3) Bangs referred to Point Romo as the nearest human settlement
that geographers of the day could be expected to find on a map. Whatever the case, we
have no doubt that the type locality of P. g. anastasae, P. p. phasma, and S. a. anastasae
was the southern end of Anastasia Island immediately north of Matanzas Inlet, on land
now part of Fort Matanzas National Monument.
Distribution and Habitat.--The original distribution of P. g. anastasae was
Anastasia Island; as revised by Osgood, its distribution expanded enormously northward
as far as Cumberland Island, Camden Co., Georgia. Cotton mice occurred mostly in
thickets of wax myrtle and Spanish bayonet and occasionally in the dune grassland of
Anastasia Island; based on habitat used by cotton mice elsewhere, the maritime live oak
forest probably also was occupied. Suitable habitat remains on Anastasia Island, but in
small, fragmented patches. Perhaps more important is the fact that these patches of
suitable habitat now are occupied by black rats (Rattus rattus; Table 5). Though we
have no direct evidence of competition between these two species, a causal relation
between colonization of Rattus and extinction of Peromyscus is possible. For a parallel
situation, refer to the case of the pallid beach mouse (Humphrey and Barbour 1981).
Considering the range of cotton mice north of Anastasia Island, the available habitat is
very extensive and includes coastal scrub, xeric oak forest, mesic forest, flatwoods, and
hydric hammock.
Survival Status.--If one accepts the current taxonomic arrangement established by
Osgood (1909), our results suggest that P. g. anastasae is apparently extirpated from
Anastasia Island but remains widespread and common elsewhere in its range. If one
rejects the current taxonomic arrangement, as we suggest above, our results suggest that
the Anastasia Island cotton mouse may be extinct.
Management.--If the subspecies is extinct, management questions are moot. If
the subspecies is widely distributed and common, management is not an important issue.
Research Needs.--A comprehensive review of geographic variation in Peromyscus
gossypinus is needed. Without good taxonomy, wildlife managers cannot determine what
genetic entities are at risk when habitat is converted to non-wildlife uses. Research also
is needed on whether a strong competitive interaction occurs between black rats and
cotton mice in Florida environments.
Anastasia Island beach mouse (Peromyscus polionotus phasma)
Background.--The Anastasia Island beach mouse (Peromyscus polionotus phasma)
was named by Bangs (1898), who said it "fairly swarmed on the sand hills at the, lower
end of the island." Published literature records it from only two sites: the type locality
at Point Romo, Anastasia Island, St. Johns Co., and on the coastal dunes of the
peninsular barrier beach extending from St. Augustine Inlet north to the border between
Duval and St. Johns counties (Ivey 1949). Ivey noted that the population did not extend
farther north on the coast into Duval County. Therefore this subspecies can be expected
to occur along the entire coast of St. Johns County (except south of Matanzas Inlet).
Much of the dune habitat along this coast has been developed around Ponte Vedre Beach
and St. Augustine. However, some undeveloped habitat remains on Anastasia Island and
between Ponte Vedra Beach and South Ponte Vedra Beach in St. Johns County.
Methods.--Sampling was conducted on Anastasia Island and vicinity from 22 May
to 12 June 1986 (Figure 2). Sites AI-9, 10, 13, 14, 15, and 17 were within Anastasia
State Recreation Area. Sites AI-7, 8, 11, 12, and 16 and Site RI-1 were within Fort
Matanzas National Monument. Sites CI-1 to 4 are on Conch Island, originally the
northernmost of several sand bars in St. Augustine Inlet, but now connected to Anastasia
Island by dredge spoil and alongshore deposition. Conch Island is part of Anastasia State
Recreation Area. Sites AI-1 to 3 are in the Fleeman tract, 700 meters of undeveloped
land north of Versaggi Road in St. Augustine Beach, which is proposed for acquisition
under the Save Our Coasts program. Sites CI-2; AI-I, 4, 5, 6, 7, 12, 13, and 14; RI-1;
and ML-1 were in dune grassland habitat judged suitable for beach mice. Sites CI-1, 3,
and 4 and AI-3, 8, 9, 10, 11, 15, 16, and 17 were in wax myrtle, palmetto, xeric oak, or
mesic oak habitats judged suitable for cotton mice. Cotton mice also would be expected
occasionally in beach mouse habitat. Site AI-2 was in dense grass judged suitable only
for cotton rats. Sampling was conducted on the barrier beach from Vilano Beach
northward from 12-20 June 1986. Sites SJ-3 to 9 were located in Guana River Wildlife
Management Area. Sites SJ-3, 5, 6, and 8 were in habitat suitable for beach mice, and
Sites SJ-4, 7, and 9 were in habitat suitable for cotton mice. Trapping was done with
lines of 40 large Sherman traps baited with rolled oats. To prevent mortality and
saturation of traps by cotton rats, which are active at all times of day, traps were set in
the late afternoon and checked and closed in the morning. Traplines were run for 1 to 3
nights.
Results.--Anastasia Island beach mice were captured in Fort Matanzas National
Monument, two sites (AI-5 and 6) north of FMNM, the Fleeman tract, and Anastasia
State Recreation Area (Table 6, Figure 2). Beach mice were not taken at a few sites
from which captures were anticipated (AI-4, RI-1, and ML-1) on the basis of habitat
characteristics. No beach mice were captured on the barrier beach north of St.
Augustine Inlet.
Taxonomy.--This beach mouse was named as Peromyscus phasma by Bangs
(1898) based on 29 specimens from the southern tip of Anastasia Island. The population
was treated as a subspecies of P. polionotus by Osgood (1909), who examined 54
specimens, all from the type locality. This taxonomic arrangement has not been
reviewed since then; Bowen (1968) dealt only with Gulf coastal subspecies of P.
polionotus.
Hall (1981) cited unreferenced marginal records of phasma from the border of St.
Johns and Duval Counties. Presumably this report is based on the published distribution
records (Ivey 1949) mentioned above. However, Ivey assigned these animals to the
subspecies phasma without making taxonomic comparisons and despite the absence of a
land connection with Anastasia Island in modern times. The resulting uncertainty may
never be solved, because the northern population now appears to be extinct and no
museum specimens from it are reported in published literature. Ivey's address in 1949
(University of New Mexico, Albuquerque) suggests one place to look for specimens.
Distribution and Habitat.--Beach mice are restricted to sand dunes vegetated
mainly by sea oats (Uniola paniculata) and dune panic grass (Paspalum amarulum), and
to the adjoining scrub, characterized by oaks (Quercus sp.) and sand pine (Pinuscclausa)
or palmetto (Serenoa repens). Though this restriction ordinarily limits the range of
beach mice to the 25-500-foot wide strip of coastal dunes as stated by Ivey (1959),
Pournelle and Barrington reported P. p. phasma in scrub up to 1800 feet from the dunes.
We found no such areas on Anastasia Island that had not been developed. P. p. phasma
had not been reported beyond the two areas listed above until the present study.
Though the distribution in the northern half of St. Johns County appears to be
no longer occupied, we found populations distributed along the length of Anastasia
Island. However, much of the former habitat has been converted to lawn or concrete
associated with development of houses and condominiums. As a result, the remaining
habitat is fragmented and discontinuous, and the remaining populations are small. The
numbers of animals we caught suggest that viable populations remain at both ends of
Anastasia Island, all along the dune grassland of both Anastasia State Recreation Area
and Fort Matanzas National Monument. The small population remaining on the Fleeman
tract south of St. Augustine Beach may not be viable.
A complicating factor is that house mice (Mus musculus) have colonized the dune
grassland on which beach mice depend. The inference that these two species compete
strongly is speculative, but Humphrey and Barbour (1981) presented prima facie
evidence for competitive exclusion of other subspecies of beach mice by house mice.
The situation on Anastasia Island is unprecedented, because for the first time the two
species have been found to co-occur locally--within traplines on Conch Island and
elsewhere in Anastasia State Recreation Area. A related issue is that activity of house
cats (Felis cattus) was widespread on Anastasia Island. The effect of these two exotic
species on survival of beach mouse populations is speculative but may be quite important
(Humphrey and Barbour 1981). Either a competitor or a predator alone can eliminate
another species, and the effects of a competitor and a predator together would be
additive. The two processes operate differently--predation stimulates reproduction of
most prey species, whereas competition surpresses reproduction of most species..
Ivey (1949) clarified Bangs (1898) report that beach mice were absent from the
beaches north of St. Augustine. Bangs referred to failure to catch animals at Burnside
Beach, a place name no longer in use. It is clear from Ivey's discussion that this locality
was near the northern end (perhaps near Mayport or Jacksonville Beach) of the peninsula
he studied, and that beach mice occurred on the southern half.
Survival Status.--On the assumption that native beach mice and exotic house
mice compete strongly enough to cause competitive exclusion of the former, we infer
that the survival status of P. p. phasma on Anastasia Island is precarious. The
populations on the northern end of the island may soon disappear. The population
appearing to be least at risk is at Fort Matanzas National Monument, where we recorded
no Mus. Even there the likelihood of colonization by Mus is high, and this population
should be considered threatened also.
Management.--Although some uncertainty exists about the threat of exotic
rodents to native beach mice, enough is known to justify management action now. The
alternative of awaiting basic research to corroborate the scanty available data risks that
the beach mouse populations could be lost in the meantime.
Because the only populations of beach mice with any chance of survival are those
on public land, management should focus on habitat acquisition and management. In the
range of P. p. phasma, the best undeveloped habitat is already under public ownership.
The Fleeman tract, 45 ha in area with 700 m of ocean-front, has been proposed for
public acquisition and is 21st in priority on the Save-Our-Coast list (St. Augustine
Record, 23 December 1986). Attention should be given to the question of whether the
beach mouse population there is viable. The other two populations of beach mice on
private land live in smaller areas (AI-5 and 6) surrounded by houses and condominiums;
probably these populations are doomed to extirpation.
Consideration should be given to introducing P. p. phasma from Anastasia Island
to the suitable habitat at Guana River Wildlife Management Area, because the risk to
the existing populations is substantial, and addition of a new population would
substantially increase the probability of survival of the taxon.
The remainder of management action should focus on minimizing changes in the
habitat of dune grassland that favor the survival of house mice. In lieu of research on
what this means, common sense should be the guide to specific management actions. All
facilities supporting visitors to public lands should be located or moved to habitats
inland of the dune grassland. This includes all buildings for staff and operation,
facilities for park concessions, campgrounds, restrooms, refuse dumpsters, and trash
barrels. Any practice that would eliminate structures in which mice could live and
scraps of garbage that mice could eat would have the desired effect. Routine, intensive
rodent control at park and concession buildings could be helpful. More frequent and
thorough refuse removal practices could be helpful. Control of free-ranging house cats
could be helpful.
Research Needs.--A survey should be done at Ponte Vedra Beach to see if the
historic population persists there. Basic research is needed to determine whether
competition really occurs between beach mice and house mice, and if so, on how strong
it is. Comparable research is needed to determine whether predation by house cats
affects beach mice. Applied research is needed on how park management practices
affect house mice. Information is needed on how far house mice will disperse from
various types of facilities, whether colonization of dune grassland is seasonal or
permanent, whether vigorous rodent control measures at park buildings affects the
ability of house mice to colonize dune grassland, and on how park managers can better
control refuse from campers, picnickers, and fishermen.
Conclusions
The conclusions of this study are summarized as follows:
Taxonomic Survival
Subspecies status Distribution Habitat status
Beach cottontail Uncertain* Canaveral Pen. to Coastal dune Secure
rabbit Sebastian Inlet* and scrub
Seashore cotton Uncertain* Canaveral Pen. to Coastal dune Secure
rat Sebastian Inlet, and scrub
Merritt Island*
Southeastern Valid Canaveral Pen. Dune grassland Secure in north,
beach mouse and Merritt Isl. south threatened in
to Hutchinson Isl. south
Goff's pocket Moot Melbourne Open uplands Extinct
gopher
Anastasia Island Not valid Southeastern U.S. Various Secure
mole
Anastasia Island Valid* Anastasia Island* Palmetto scrub, Extinct**
cotton mouse hammock
Anastasia Island Valid Anastasia Island Dune grassland Threatened
beach mouse
Review of geographic variation is needed to confirm these interpretations of taxonomic status
and distribution.
** Concluding that this subspecies is insular and extinct requires rejecting the current taxonomic
arrangement; otherwise the subspecies is widespread and common.
~~ _i__~llil___i~_
1. Because of uncertain taxonomic status, the distribution of the beach cottontail
rabbit can be interpreted either as extensive or less so. A common-sense interpretation
shows this upland rabbit is widely distributed on the Canaveral Peninsula, where
excellent, extensive habitat remains and populations are sizeable. However, whether the
subspecies occupies this entire area is debatable. A narrower interpretation, confining
the subspecies to East Peninsula, invokes loss of most cottontail habitat from Melbourne
Beach north, but much good cottontail habitat remains south of Melbourne Beach.
Pending a review of geographic variation in Florida cottontails to allow better definition
of the distribution of the beach subspecies, its survival appears to be secured by the
substantial amount of habitat protected from development by public ownership. No
management issues are apparent.
2. Uncertain taxonomic status of the seashore cotton rat makes its distribution
debatable. At a minimum, this subspecies is common and widely distributed on East
Peninsula. More probably, its range also includes Canaveral Peninsula and Merritt
Island. At a maximum, its range also includes other barrier islands. Even if future
study of geographic variation shows that the subspecies occurs only on East Peninsula,
the population probably can survive indefinitely, because substantial amounts of habitat
and public land are available there.
3. The range of the southeastern beach mouse has been substantially reduced and
fragmented by habitat conversion and invasion of exotic mammals over the past century.
These threats are anticipated to continue, and the range of this subspecies ultimately
may be limited to public land that is properly managed. Substantial populations remain
on Canaveral Peninsula, Merritt Island, the southern half of Sebastian Inlet State
Recreation Area, and Pepper Park. Management of the dune grassland on public lands
in these areas should strive to prevent colonization or activity of house mice and house
cats, through construction setbacks, refuse control, and predator removal. Introduction
of beach mice to the northern portion of Sebastian Inlet State Recreation Area should be
considered.
4. Goff's pocket gopher appears to be extinct. No action is required.
5. The Anastasia Island mole is widespread and common on Anastasia Island.
The taxon recently was found to be indistinguishable from moles from most of
peninsular Florida and the southeastern United States. No action is required.
6. If one accepts the current taxonomic arrangement, the Anastasia Island cotton
mouse is apparently extirpated from Anastasia Island but remains widespread and
common elsewhere in its range. However, we favor the original taxonomic arrangement,
with a distribution limited to Anastasia Island. Under this interpretation, the Anastasia
Island cotton mouse appears to be extinct. In the first case, management is not an
important issue; in the second, management issues are moot. Although strictly academic,
a comprehensive review of geographic variation in Peromyscus gossypinus is needed.
7. The survival status of the Anastasia Island beach mouse is precarious. It
already is extirpated from the northern half of its range, from Villano Beach north to
Ponte Vedra Beach. Its remaining range on Anastasia Island appears to be reduced and
fragmented. The subspecies persists in large, viable populations on public land at each
end of Anastasia Island (Anastasia State Recreation Area and Fort Matanzas National
Monument) and in small, marginal populations on at least three parcels of privately
owned land. The latter three populations are threatened by habitat conversion. The
population on the northern end of the island may soon disappear, because the dune
grassland has been colonized by house mice, which are thought to cause competitive
exclusion of beach mice. The population appearing to be least at risk is at Fort
Matanzas National Monument. Consideration should be given to introducing beach mice
from Anastasia Island to the suitable habitat at Guana River Wildlife Management Area.
Applied research is needed on how park management practices affect house mice.
Management of the dune grassland on public lands should strive to prevent colonization
37
or activity of house mice and house cats, through construction setbacks, refuse control,
and predator removal. Remedial management action is needed in Anastasia State
Recreation Area, and preventative action is appropriate for Fort Matanzas National
Monument.
Literature Cited
Allen, J. A. 1890. Bull. Amer. Mus. Nat. Hist. 3:160.
Allen, G. M. 1920. An insular race of cotton rat from the Florida Keys. J. Mammal.
1:235-236.
Baker, R. H. 1969. Cotton rats of the Sigmodon fulviventer group. Pp. 177-232 in J.
K. Jones, Jr., (ed.), Contributions in mammalogy. Misc. Publ. Mus. Nat. Hist.,
Univ. Kansas, 51:1-428.
Bangs, O. 1896. The cotton mouse, Peromyscus gossypinus. Proc. Biol. Soc. Wash.
10:119-125.
Bangs, O. 1898. The land mammals of peninsular Florida and the coastal region of
Georgia. Boston Soc. Nat. Hist. Proc. 28:157-235.
Bowen, W. W. 1968. Variation and evolution of Gulf coast populations of beach mice,
Peromyscus polionotus. Bull. Florida State Museum, Biol. Sciences 12(1):1-91.
Chapman, F. M. 1889a. On the habits of the round-tailed muskrat (Neofiber alleni
True). Amer. Mus. Nat Hist. Bull. 2:119-122.
Chapman, F. M. 1889b. Description of a new species of the genus Sigmodon from
southern Florida. Amer. Mus. Nat Hist. Bull. 2:118.
Chapman, F. M. 1889c. Description of two apparently new species of the genus
Hesperomys from Florida. Amer. Mus. Nat Hist. Bull. 2:117.
Dalby, P. L. and H. A. Lillevik. 1969. Taxonomic analysis of electrophoretic blood
serum patterns in the cotton rat, Sigmodon. Publ. Mus. Michigan State Univ.,
Biol. Series, 4(3):68-101.
Elliot, D. G. 1901. A list of mammals obtained by Thaddeus Surber in North and South
Carolina, Georgia, and Florida. Field Columbian Mus., Zool. Ser., 3:39-57.
Extine, D. D. and I. J. Stout. 1987. Dispersion and habitat occupancy of the beach
mouse, Peromyscus polionotus niveiventris. J. Mammal. 68:297-304.
Florida Game and Fresh Water Fish Commission. 1985. Official lists of endangered and
potentially endangered fauna and flora in Florida. Tallahassee, Florida. 24 p.
Hall, E. R. 1981. The mammals of North America. John Wiley and Sons, New York.
1175 p.
Howell, A. H. 1939. Descriptions of five new mammals from Florida. J. Mammal.
20:363-365.
Howell, A. H. 1943. Two new cotton rats from Florida. Proc. Biol. Soc. Washington
56:73-76.
Howell, A. H. Unpublished manuscript. Florida mammals. In files of U. S. Fish and
Wildlife Service, Jacksonville, Florida.
Humphrey, S. R. 1981. Goffs pocket gopher (Geomys pinetis goffi) is extinct. Florida
Sci. 44:250-252.
Humphrey, S. R. and D. B. Barbour. 1981. Status and habitat of three subspecies of
Peromyscus polionotus in Florida. J. Mammal. 62:840-844.
Ivey, R. D. 1949. Life history notes on three mice from the Florida east coast. J.
Mammal. 30:157-162.
Ivey, R. D. 1959. The mammals of Palm Valley, Florida. J. Mammal. 40:585-591.
Jackson, H. H. T. 1915. A review of the American moles. North Amer. Fauna 38. 100
P.
Layne, J. N. 1974. The land mammals of South Florida. Pp. 386-413 in P. J. Gleason
(ed.), Environments of South Florida: present and past. Miami Geol. Soc.
Memoir 2, 452 p.
Nelson, E. W. 1909. The rabbits of North America. North Amer. Fauna 29. 314 p.
Osgood, W. H. 1909. Revision of the mice of the American genus Peromyscus. North
Amer. Fauna 28. 285 p.
Pournelle, G. H. and B. A. Barrington. 1953. Notes on mammals of Anastasia Island,
St. Johns County, Florida. J. Mammal. 34:133-135.
Sealander, R. K., M. H. Smith, S. Y. Yang, W. E. Johnson, and J. B. Gentry. 1971.
Biochemical polymorphism and systematics in the genus Peromyscus. I.
Variation in the old-field mouse (Peromyscus polionotus). Univ. Texas Studies in
Genetics 6:49-90.
Schwartz, A. 1956. The cottontail rabbits (Sylvilagus floridanus) of peninsular Florida.
Proc. Biol. Soc. Wash. 69:145-151.
Sherman, H. B. 1944. A new subspecies of Geomys from Florida. Proc. New England
Zoological Club 23:37-40.
U. S. Fish and Wildlife Service. 1984. Endangered and threatened wildlife and plants.
U. S. Government Printing Office. 24 p.
U. S. Fish and Wildlife Service. 1985. Endangered and threatened wildlife and plants;
review of vertebrate wildlife; notice of review. Federal Register 50:37958-37967.
Wilkins, K. T. and D. J. Schmidly. 1980. The effects of mowing highway rights-of-
way on small mammals. Proc. Second National Symp. of Environ. Concerns in
Rights-of-Way Manage. Cary Arboretum, New York Botanical Gardens, Bronx,
NY.
Yates, T. L. 1978. Systematics and evolution of North American moles (Insectivora:
Talpidae). Ph.D. Diss., Texas Tech University. 304 p.
Zimmerman, E. G. 1970. Karyology, systematics and chromosomal evolution in the
rodent genus, Sigmodon. Publ. Mus. Michigan State Univ., Biol. Series, 4:385-
454.
|
RSS
HIDE
