Status survey of the Schaus swallowtail in Florida in 1984

Material Information

Status survey of the Schaus swallowtail in Florida in 1984
Emmel, Thomas C
University of Florida -- School of Forest Resources and Conservation
Place of Publication:
Gainesville, Fla
Florida Cooperative Fish and Wildlife Research Unit, School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida
School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida
Publication Date:
Copyright Date:
Physical Description:
38 leaves, [1] leaf of plates. : ill., maps ; 28 cm.


Subjects / Keywords:
Papilionidae -- Florida ( lcsh )
Butterflies -- Florida ( lcsh )
Key Largo ( local )
Elliott Key ( local )
Hammocks ( jstor )
Butterflies ( jstor )
National parks ( jstor )
bibliography ( marcgt )
government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )


Includes bibliographical references (leaves 27-28).
General Note:
"15 March 1985."
General Note:
"Supported by: U.S. Department of the Interior Fish and Wildlife Service."
Statement of Responsibility:
Thomas C. Emmel.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
28570158 ( OCLC )
001135505 ( AlephBibNum )
AFN4696 ( NOTIS )


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Thomas C. Emmel

Florida Cooperative Fish and Wildlife Research Unit
117 Newins-Ziegler Hall
School of Forest Resources and Conservation
Institute of Food and Agricultural Sciences
University of Florida, Gainesville, FL 32611


Department of Zoology
Division of Lepidoptera Research
421 Bartram Hall West
University of Florida, Gainesville, FL


Supported by:

U. S. Department of the Interior
Fish and Wildlife Service
Cooperative Agreement No. 14-16-0009-1544
RWO #18

15 March 1985

This paper is to be cited as Emmel, Thomas C., 1985. Status Survey of
the Schaus Swallowtail in Florida in 1984. Technical Report No. 14.
Florida Cooperative Fish & Wildlife Research Unit, University of Florida,
Gainesville. 39 pp.


Acknowledgements 1

Abstract 2

Part I: Introduction 4

Part II: Methods and Researchers 6

Part III: Results

A. Status Immediately Prior to 1984 8
B. Status Survey Results for 1984 10
C. Key Largo . 10
D. The Florida Keys South of Key Largo 11
E. Specific Comments on Certain Areas:
(1) Upper Matecumbe Key 12
(2) Lower Matecumbe Key 13
(3) Long Key 13
(4) Big Pine Key 13
(5) Cudjoe Key and Sugarloaf Key 14
(6) Key West 14
F. Biscayne National Park 14
(1) Elliott Key 14
(2) Old Rhodes Key 15
(3) Totten Key 16
(4) Everglades National Park 17

Part IV: Discussion

A. General Ecology of the Schaus Swallowtail 18
B. Elliott Key Population 19
C. Old Rhodes Key Population 20
D. Totten Key Population 21
E. Key Largo Population 21

Part V: Conclusions and Recommendations 23

References 27

Map Figures 29

Color Plate Figures


This report was produced as a result of research funded by
the U.S. Fish and Wildlife Service through Contract
#14-16-0004-80-027 from the U.S. Department of the Interior.
David J. Wesley and Michael Bentzien of the U.S. Fish & Wildlife
Service Endangered Species Field Station (Jacksonville, Florida)
greatly facilitated the project in many ways, and their help is
gratefully acknowledged.

The National Park Service staff at Biscayne National Park
were of inestimable help during the 1984 survey work, especially
Superintendent James A. Sanders who issued a permit to work on the
butterfly throughout the Park and who provided boat transportation
and ranger assistance at all times; Mrs. Lorrie Sprague, Research
Management and Terrestrial Section Chief, who accompanied and
assisted us on all trips; and Miss Nancy Douglass, Seasonal Park
Aide, who assisted us on not only our trips but made many
additional trips on Elliott Key to census the Schaus Swallowtail
population for us.

H. Franklin Percival (Florida Cooperative Fish and Wildlife
Unit at the University of Florida) ably coordinated administration
of the contract among the U.S. Fish and Wildlife Service, the
Florida Game and Fresh Water Fish Commission, the Department of
Zoology at U.F., and the School of Forest Resources and
Conservation at U.F., to insure the successful completion of the
project. His help was invaluable in all respects.

The Florida Game and Fresh Water Fish Commission (Don Wood,
endangered species coordinator) kindly granted a permit to handle
the Schaus Swallowtail adults briefly during the 1984 field


- 1 -


The purpose of this research was to determine the 1984

population status and geographic distribution of the Schaus

Swallowtail butterfly, eiaijg (UrMCS .dfltS) ACiaodegmus ooncrag

Schaus, a large and colorful endemic insect in south Florida that

is currently on the United States List of Endangered Species and

appears to be close to extinction. Its range has steadily

declined during the past century. Intensive surveys were carried

throughout the Florida Keys and the south Florida mainland to

determine the location of extant colonies of the butterfly species

and its larval food plants, to determine approximate population

sizes, and make ecological observations on its population biology.

The Schaus Swallowtail was at extremely low population levels

in 1984. On northern Key Largo, only one adult Schaus was

observed. In Biscayne National Park, the total population size

was estimated to be thirty adults on Elliott Key, twenty-four

adults on Old Rhodes Key, and sixteen adults on Totten Key. The

adult flight period extended from the first week of May to mid

June. No eggs or larval instars were found from May to September

1984, despite intensive surveys. The larval foodplants, torchwood

(Ayris) and wild lime (_anhgxylMg), were present in good numbers

in the four recorded adult population areas and were found

elsewhere in many hammocks on the Keys and mainland where

e0SEgaOQ does not presently exist.

The occurrence of the butterfly on northern Key Largo

(Hammock 13-14 boundary) in 1984 is of special interest because it

was not found on Key Largo in intensive 1980 and 1981 surveys

(U.S. Fish & Wildlife Service, 1982). Apparently, a colony has

been persisting there since the Schaus Swallowtail's last peak of

abundance in 1971-1972.


The Schaus Swallowtail butterfly (E�ilio (Heraclides)

arijtgd4gaM RgQnc e~a Schaus) is considered one of the rarest

resident butterflies in the United States and is listed as

endangered by both the State of Florida and the federal

government. It is Florida's foremost endemic butterfly, being

known historically only from the southeastern tip of the Florida

peninsula and portions of the Florida Keys.

The present population status and present distribution of

the butterfly have been uncertain since the last surveys carried

out in 1980 and 1981 (U.S. Fish & Wildlife Service, 1982). The

overall trends in its historic range and numerical abundance in

the last eighty years have been in the direction of decline. It

has not been recorded from the mainland since 1924, and from the

1940's to the 1970's, it has been found only on two of the middle

and upper Florida Keys and in Biscayne National Park.

The ecological and evolutionary reasons for the limitation

of the range of the Schaus Swallowtailbutterfly to only a small

fraction of its potential range are not understood. Habitat

alteration by urban development is believed to have been the

primary cause of extermination of the species from the Florida

peninsula and is currently threatening the important hardwood

hammock habitat for the species on Key Largo. Widespread aerial

application of insecticides, overcollection, and natural weather

factors have also been implicated in the severe range constriction

and population decline during this century.

- 4 -

The U.S. Fish and Wildlife Service (USF&WS) determined that

a status review was necessary in 1984 in order to establish the

present distribution and relative abundance of the Schaus

Swallowtail butterfly in Florida. In 1980 and 1981, the Florida

Game and Fresh Water Fish Commission (FG&FWFC) conducted research

on the historic and current distribution of the species. In order

to complete the survey (published as U.S. Fish & Wildlife Service,

1982) and update the knowledge on the status of the species, the

present investigator, in cooperation with the FG&FWFC, the

National Park Service, the USF&WS, and the Florida Cooperative

Fish and Wildlife Research Unit, conducted surveys during 1984

under the support of the USF&WS to determine the current

distribution and relative abundance of the species.

The results of this study should provide information

enabling effective management planning and actions, and the

identification of areas for increased attention as regards future

steps and research to assure the survival of this large,

distinctive tropical species in the United States fauna.

- 5 -


Ground surveys were conducted within the butterfly's known

recent range, and appropriate hammock habitats outside that range,

during the reported usual flight and breeding season (May-June)

and subsequent months (July-August-September) to check for a

possible second brood. Special attention was paid to the extant

hammock habitat on the keys in Biscayne National Park, Key Largo,

and Lower Matecumbe Key, the only reported population areas for

the Schaus Swallowtail since 1940 (Figure 1). Potential Schaus

Swallowtail habitat on the other keys and on the mainland north to

Miami and Fort Lauderdale and west into Everglades National Park

were searched for previously undetected populations. Transects

were established in search areas and distribution surveys were

conducted on foot by at least two observers during all daylight

hours when normal flight activity would be expected. Additional

examination of the larval host plants was made for eggs, larvae,

and pupae as indicators of established breeding colonies. Where

butterflies were found, information was recorded on the exact

locations, wing condition ("age") of adults, if they were netted,

sex of adult if identified, and habitat use by the butterfly while

under observation.

These surveys were started on May 3 and continued at

intervals through September 23, 1985. They were conducted by at

least two field workers, the principal investigator (Thomas C.

Emmel, Professor of Zoology and Director of the Division of

Lepidoptera Research at the University of Florida) and an

experienced research assistant (James L. Nation, Jr. of the

- 6 -

Department of Zoology of U.F.). In Biscayne National Park, the

survey work was very substantially helped by the participation of

Mrs. Lorrie Sprague, Research Management and Terrestrial Section

Chief (National Park Service), and Miss Nancy Douglass, Seasonal

Park Aide. In addition, Miss Douglass conducted twelve weekly or

more frequent surveys on Elliott Key from May 18 through August 7,

to ascertain the Schaus population's flight period at times that

the other investigators could not be present.

Because of the extremely low population numbers of the

adults in 1984, no capture-mark-recapture studies per se were

performed on the butterfly. It was felt that the usual paint or

dye marking procedures employed in butterfly population studies

entailed some risk and were not necessary with such reduced

densities. Natural wing damage on each specimen proved to be

sufficiently distinctive to identify the butterflies individually

upon recapture. Each butterfly was gently netted, examined for

several seconds in the hand to record wing condition, sex, and

other data, and then released promptly. No injury was incurred by

any specimen.

In the survey for immature stages in the Schaus' life

cycle, torchwood and Zagnthaxin (wild lime) trees were visually

searched from ground level up to about eight feet above the

ground. Searching was conducted during daylight hours, and

canopy-level foilage of host plants could not be searched; it is

quite possible that nocturnal feeding and preferential oviposition

on tree-top foliage of torchwood lessened the chances of observing

immature stages during this year of extremely low population


- 7 -



The Schaus Swallowtail, PEailio (Hera.lides) aristodemus

Roncg anus Schaus, has always been confined to the south Florida

area, with its northern limit near Miami (described as a new

species from there by Schaus in 1911) and its normal southern

limit somewhere in the upper keys (from Lower Matecumbe Key north,

with only several records from the lower keys, including Key

West). The primary host plant, Torchwood (QAmris elemifera),

however, occurs in hammocks throughout the lower and upper keys,

and on the Atlantic Coast of Florida's mainland north past Miami

to Volusia County (Little, 1978). The secondary host plant, Wild

Lime (Zanthoxylum fagara), which was first discovered to be a host

by Rutkowski (1971), occurs in all the preceding areas and

northward to central Florida, as well as south (with Torchwood)

into the Bahamas, the West Indies, and Central America (Little,

1978). The ecological and evolutionary reasons for the limitation

of the range of the Schaus Swallowtail butterfly to only a small

fraction of this potential range are not understood (U.S. Fish &

Wildlife Service, 1982). Habitat alteration by urban development

is believed to have been the primary cause of extermination of

eonceanus from the Florida peninsula, and as noted earlier, is

currently threatening the important hardwood hammock habitat for

the species on Key Largo. However, habitat destruction in most of

the lower keys was not extensive enough between the late 1940's

and 1970 to explain the near-sudden absence of the butterfly from

those areas at that time. Widespread aerial application of

- 8 -

insecticides for mosquito control by Monroe County, overcollecting

by commercial and amateur lepidopterists, and natural weather

factors have also been implicated in the severe range constriction

and population decline of 20gceanus during the recent part of this

century (U.S. Fish and Wildlife Service, 1982).

In 1980 and 1981, the Florida Game and Fresh Water Fish

Commission conducted research on the historic and the current

distribution of the subject species (published as U.S. Fish and

Wildlife Service, 1982). In those years, the known breeding

colonies of Schaus Swallowtail were restricted to two islands (Old

Rhodes and Elliott keys) in Biscayne National Park and one small

100m2 area on northern Key Largo in 1980 (three first-instar

larvae found on May 27, 1980, but no evidence of breeding found

there in 1981). Adult numbers were low in the Park in 1980, and

perhaps even lower in 1981. The total observed population on

Elliott Key in 1981 was not more than about ten adults (eight

observed from May 13 to July 8 by Loftus, and ten observed on May

17 by Krizek). The Torchwood leaf production may have been

retarded by a prolonged drought in southern Florida during early

to mid-1981. Several areas in southern Biscayne National Park and

south to northern Key Largo that could have supported Schaus

Swallowtails were not searched in those years (USF&WS, 1982). On

May 18, 1982, Covell (1982) informally surveyed Rgognanus on

Elliott Key in Biscayne National Park and recorded thirty-six

sightings, saying also that the species seemed to be "up" in

numbers from his previous experience. No other surveys have been

reported for 1982 or 1983.



One small fresh on~ganus, probably a male, was seen on Key

Largo (Figure 2) one-half mile south of the Carysfort Yacht Club

on May 5 at 10:00 a.m. on a clear warm day. It was flying across

an open area, having just left a hammock margin at the eastern end

of the border between Hammock 13 and 14 in the Key Largo Beach and

Tennis Club property. Two large male Paoilio acres hontae were

netted here in fresh condition between 9:30 and 10:30 a.m. on this

date, along with many pierids, nymphalids and lycaenid

butterflies. The entire area of northern Key Largo, both west and

east of Highway 905 and north to the Ocean Reef Club entrance, was

checked on this same data and no further specimens of Dgoneanus

were seen.

The same areas were checked again on May 7-8 with no

discovery of further gonceanus. On June 2-3 and on later visits

in June, August and September, the entire northern half of Key

Largo was checked intensively and the southern half less

intensively. No goncganus adults were found on these dates;

however, both male and female crgehsg nte in fresh condition were

seen and netted. Large numbers of young torchwood and wild lime

food plants were found in good condition in mature hammock areas

across northeastern Key Largo and as far south as the junction of

Highway 905 and U.S. 1. No ggnceanus immature stages were found

on these dates. Large numbers of pierid, nymphalid and lycaenid

butterfly species were found throughout Key Largo in June, August,

- 10 -

and September under excellent weather conditions for flight; few

butterflies, however, were observed here in May.


During the period of May 5-11, 1984, a comprehensive survey

was conducted throughout the Florida Keys from Key Largo south to

Key West. The purpose of this intensive survey during the

recorded peak of the usual annual oonceanus flight period was to

ascertain whether any populations of epngeanus were present in

these former areas of its historic range. The following Keys were

checked intensively:

South Key Largo

Plantation Key

Windly Key

Upper Matecumbe Key

Lower Matecumbe Key

Fiesta Key

Long Key

Conch Key

Duck Key

Brassey Key

Pidgeon Key

Little Duck Key

Missouri Key

Ohio Key

Bahia Honda Key

20 minutes

1 hour

1 hour

- 11 -

West Summerland Key

Big Pine Key

Little Torch Key

Middle Torch Key

Ramrod Key

Summerland Key

Cudjoe Key

Sugarloaf Key

Park Key

Lower Sugarloaf Key

Saddle Bunch Keys

Big Coppitt Key

Rockland Key

Stock Island

Key West

30 minutes

The times given on several of the keys represents the time

spent on intensive research of the hammocks for Schaus Swallow-

tail butterflies. The keys without times do not have sufficient

hammock to support the butterflies and therefore were not

researched extensively.

Specific comments .on certain of these areas follow:


Some hammock patches were present here, despite the heavy

strip development around Mile Marker 81. In the specifically-

suitable roadside-park-area hammock to the west side of the

highway, we found no signs of torchwood or wild lime food plant or

of the butterfly. On side roads off to the east, there was tall

- 12 -

hammock near the Green Turtle Inn but no sign of _gnceagns or even

of Liqguus tree snails (which are usually a good indicator of

undisturbed hammock)


The south end and middle portion of Lower Matecumbe Key had

several lot-sized hammock areas between the houses and urban

developments. We checked several hammock areas here but found no

pgnceaua. The Giant Swallowtail Pagilis GceRshoOtes was

reasonably common on Lower Matecumbe Key in the Columbus Drive

area. This key, where the butterfly once occurred (until at least

1949, and possibly to 1964), has extensive housing and business

development throughout its length and there appears to be little

chance the butterfly could survive here today.


Of all the keys accessible from the highway in the lower

Florida Keys, Long Key State Recreation area (along the nature

trail) seem to provide the geographically closest potential

habitat to Key West, site of a very old (1885) record for

gonceanus. The Long Key State Recreation area has some short

tropical hammock, along with scrub and mangroves, but there were

no signs of any goggnanus population on this island.


This Key was intensively checked because of the fair amount

of natural vegetation still left on the key. We found several

rare tropical butterfly species, such as Strcymn agis bartrami,

- 13 -

here in the pines and palmettos; however, there was no sign of

qgnseanus or of suitable tropical hardwood habitat for qgnceanus.


These two keys have low hammock vegetation with reasonably

abundant torchwood (U.S. Fish and Wildlife Service, 1982), but we

found no mature tall hammock that would match the more northern

tropical hardwood hammocks which RgncqEQns presently occupies.

Historically, no Schaus adults or immatures have ever been found



South of Sugarloaf Key, we found no suitable or even

marginal habitat for Egnceanus on any key. On Key West, site of

an 1885 record with the specimen currently in the Carnegie Museum,

no potential habitat for pgaceanus remains today.



Sixteen survey trips were made to Elliott Key (Figure 3)

during 1984, four by the U.F. personnel (May 10, June 4 and 5,

September 22) and twelve by Nancy Douglass (May 18, 21, 22, 24,

25; June 11, 12, 20, 26; July 10; August 1, 7). Schaus

Swallowtail adults were observed from May 10 through June 5 but

not thereafter. No immature stages were found. Heavy rains and

flooding after June 5th made the southern portion of the Key

inaccessible much of the time to foot travel. These rains may

have materially contributed to the short flight season of the

- 14 -

adults, as we observed rapid deterioration in wing condition of

wild adults even in May under relatively dry conditions.

The total flying population in the 1984 season on Elliott

Key was estimated to be thirty adult Schaus Swallowtails, from

recaptures of naturally-marked butterflies. The maximum number

observed on any one day was seven (May 10th). Only males were

found in early May; by June 4-5, the population had declined to

about 5-6 relatively old adults, but females now represented half

of those seen. All specimens seen were along the Petrel Point

Trail in the southern part of the Key; none were encountered on

Spite Road itself. More than fifty torchwood trees were checked

for larvae and eggs on the short (800 feet) Petrel Point trail, as

were forty-five more scattered torchwood and Zanthogylum along

several miles of Spite road. Adult activity was encountered

between 9:10 a.m. and 1:10 p.m. Later in the afternoon, no adults

were seen. Early in the morning (9:10 a.m.), one female Schaus was

observed feeding on the small white flowers of Cheese Shrub

(MoCrinda Cyvgc). Much of the time of adult males was spent in

apparent thermoregulating, landing on sunlit branches of torchwood

with wings outspread for several minutes at a time. Hindwings

frequently had bird beak marks across the scaling or had tears in

the wing margins and had missing tails. All adults on Elliott Key

were encountered in an area of about 700 linear feet of the Petrel

Point trail starting at Spite Road, indicating perhaps site

fidelity and little wandering from their home hammock area in this

year of extremely low population levels.

- 15 -


The Schaus Swallowtail population on this key (Figure 3)

south of Elliott Key was estimated to be a maximum of twenty-four

adults in 1984. The maximum number on-any one day was on June 4th

when nine gngganug males and one female were censused. The

population was apparently at the peak of its flight season, with a

normal age distribution curve of two nearly-freshly-emerged

adults, six intermediate-condition adults, and two worn adults

(one male, one female). In September, the abundant torchwood here

showed old feeding damage but no larvae were present. Liguus tree

snails and the tropical Florida Purplewing butterfly (gjniag

tatila) were found in numbers in the mature hammock here.. The

Giant Swallowtail, EPailio creshontes also occurred here.


The Schaus Swallowtail population on this key across

Caesar's Creek south of Elliott Key (Figure 3) was estimated to be

12-16 adults in 1984. The peak of the flight season was

apparently in May. Two worn males were netted here, plus two

other adults observed, during a June 4th visit. Four Giant

Swallowtails (e~A3ili9 RjgRh0gota) in freshly emerged condition

were found among the forty acres of planted wild key lime trees

(genus Citus) present near the landing site on this key.

Torchwood and Zanthgjyumr , wild lime trees were located here in

abundance. On the September 22nd visit, a second-instar -Papiig

larva was found here on ~anthgxlumi. Photographs of it were later

identified by H. David Baggett as of a second-instar Eailigo

cresphgn9te larva. Two adult Pa21ilg resEhgntkes were seen here

- 16 -

on September 22, but no pgnceanus adults or immature stages were

encountered on that date.


The eastern portion of Everglades National Park, including

the Royal Palm visitor center area hammock and local hammocks to

the west, were found to be potentially suitable habitat where

PaRilio aristodemus gneangus could possibly occur, but no adults

or immatures were encountered in May surveys. The Giant

Swallowtail Paeilio Sresehontes was observed in fair numbers here.

- 17 -



remarkably adapted to the tropical hardwood hammock habitat. Of

all butterflies known to me, they resemble the tropical nymphalid

genus Heligonij most in their highly modified flight behavior,

their obvious ability to navigate slowly and carefully around fine

obstacles such as branches and spider webs, and their apparently

high degree of learning ability ("intelligence") in terms of

remembering a territorial flight path and travelling along it on a

regular, predictable circuit. They alight frequently on torchwood

leaves about 3-4 feet off the ground and "bask" with outspread

wings in the sunfleck for a few minutes; they feed on nectar of

small white-flowered shrubs; they investigate other 2gnceanus that

enter their territory and fly closely (but slowly) around them for

a few moments; etc. They avoid entering open areas unless they

are alarmed by someone pursuing them too closely. The frequent

tears in the wings suggest a daily toll of .damage resulting from

maneuvering through the hardwood hammocks, while beak marks and

missing tail sections cleanly snipped off suggest rather frequent

bird attacks. It is likely that they live only two weeks at most

as adults at this rate of wing wear and apparent predation

attempts. Yet the extended flight season from the end of April to

mid-June suggests that the overwintering (diapausing) pupae do not

emerge synchronously, but that adults emerge over at least a 3-4

week period. It is remarkably easy to observe and follow this

large and colorful swallowtail through the hammocks or along the

trails. I took close-up photographs at distances of six inches

- 18 -

with no great difficulty. The wing-color resemblance in flight to

the sympatric, common and distasteful heliconiine butterfly

species, the Zebra (Heliscnius charitonius), is remarkable also

and the similarity in behavior as well as color pattern during

flight suggests selection for an incipient mimetic relationship

that would protect the adult Schaus Swallowtails against bird


It is clear that suitable torchwood plants for oviposition,

with new growth following the late spring and summer rains, occur

within the mature hammocks as well as along trails cut through the

hammock. In fact, a greater diversity of torchwood trees, from

very young to mature canopy-level trees, occurs within the mature

hammocks as compared to areas undergoing succession (cf.

Rutkowski, 1971). From talking with a number of lepidopterists

who have observed the immatures in nature and seen the adults

ovipositing, the adult females appear to prefer ovipositing on

torchwood or wild lime under the canopy of taller hammock where

dappled sunlight comes through, but not intense sunlight or total

shade. This habit probably relates to a narrow range of

thermoregulatory preference or tolerance on the part of the adult.

Time budgets on males and females observed in May and June of 1984

indicated as much as 55% of their time between the peak flight

hours of 10:00 a.m. and 1:00 p.m. is spent in basking behavior,

sitting with wings outspread on torchwood leaves in a sun fleck.

ELLIOTT KEY POPULATION: The peak of the 1984 flight was in early

May. Seven gonceanus males were actually observed in the hand, or

at very close range on May 10th, and from capture-recapture data,

- 19 -

the population on that day can be extrapolated to have consisted

of approximately 15 males. Assuming a 1:1 sex ratio in eventual

emergence (females emerging later than the males), the total

population size during May was about 30 individuals in the

south-central part of Elliot Key around Petrel Point. Adults were

not flying elsewhere on the island at this time, or at any later

date (Biscayne National Park naturalists checked these sites

weekly, in addition to our U.F. personnel visits). One male and

one female were actually observed here in the hand on June 5th

under good weather conditions, a record represented two-thirds of

the flying population seen at Petrel Point on this visit. None

was seen subsequently. Despite diligent searching in May, June,

July, August, and September, no immatures were found. The

torclwood and key lime were in good shape. Heavy continuous rains

at intervals of a week or so in May and June may have limited

adult activity this year to lower levels? however, the lack of

adults in any numbers on Key Largo where less rain fell suggests

another as yet unidentified cause of population decrease.

OLD RHODES KEY POPULATION: The peak of the 1984 flight was in

late May and the first week of June. Six males and one female

were actually handled and identified, with a series of other males

and one unmarked female observed at close range. From these

observations, the total population size on this date can be

estimated to be approximately 12 males and 2 females, with about

24 butterflies representing the total flying adult population of

gonceanus on Old Rhodes Key during May.

TOTTEN KEY POPULATION: The peak of the 1984 flight season was in

May. By early June, only worn adults (a total of 6) were seen

here. The estimated population size from capture-observation data

was about 8-10 males for June 4th, extrapolating to a total

population of approximately 16-20 Qgceangs for the Key area.

KEY LARGO POPULATION: A little more than ten years ago, gOnceanuR

was passing through one of the largest, if not the largest,

population peaks ever recorded in any of the cycles for this

species. In 1984, the numbers were extraordinarily low, with one

male (?) being observed by the present investigators and no adults

(as for as known) being collected that season by any of the

PaPilio collectors visiting the Keys for that purpose. The

attached map (Figure 2) plots the known distribution of specimens

collected in the 1970's and the location of the 1984 specimen

observed at the boundary of Hammocks 13 and 14 one-half mile south

of the Carysfort Yacht Club road turnoff. These data were

gathered from published records on museum specimens with full

data, and from unpublished records taken by collectors who wished

to remain anonymous but shared information for the purposes of

this status survey. It should be noted that most records (Hammock

Nos. L(1)6, 9, 10, 11, 13, 14) are concentrated in the remaining.

native hammock areas of northern Key Largo, and that the

southernmost record known since 1970 is just north of Gulfstream

Shores (Hammock No. L(2)5).

From all accounts of experienced collectors of Schaus

Swallowtails, the butterfly has always occurred in numbers east of

Highway 905 and particularly along trails or inside native

- 21 -

hammocks (with a relatively open understory composed of torchwood,

wild lime, poisonwood, and young hardwood saplings) where dappled

sunlight penetrates at mid-day. While it flies slowly along the

edges of hammocks on occasion, it very rarely flies into open

areas. On the other hand, its congener, the Giant Swallowtail

PagRili cres2Rhgan is usually flying relatively rapidly across

open areas and visiting flowers along roadsides or in fields;

female cgehgonSet frequent the hammocks more than males.


The populations on the Keys in Biscayne National Park,

while very low for continued species survival if considered

individually, form a viable nucleus in the aggregate for the

Schaus Swallowtail's existence and for captive-propagation stock.

The chief danger of having such a geographially-limited nucleus

arrises from natural disasters, such as hurricanes, fires, or

winter freezes, wiping out the sole remaining viable stocks.

Because of their size (larger than the Key Largo population), they

are the most suitable populations to continue more intensive

studies in the future on the species' population ecology,

especially population size, life span as adults, predation and

parasitism, and amount of movement of adults (especially between

keys or across distances representing such degrees of isolation).

These populations are rarely seen by human visitors because few

can brave the hordes of mosquitoes and flooded ground conditions

during the time of the usual Schaus flight period. Thus few

people can enjoy their beauty, whereas on keys from Key Largo

south, thousands of visitors a month could potentially see these

attractive butterflies during past peak years. It seems

important, therefore, to foster the butterfly's continued


On the basis of available torchwood hast plants and

historical records for Schaus Swallowtail adutls, the optimum

hammock characteristics for the butterfly on Key Largo are found


Hammock L(1)6

Hammock L(1)11

Hammock L(1)9

Hammock L(1)10 B

Hammock L(1)13-14

Hammock L(2)1

as depicted in Figure 2 (sections L-1 and L-2 of Northern Key

Largo) of the Recovery Plan of the U.S. Fish & Wildlife Service

(1982, p. 55). As far as the preservation of the butterfly is

concerned, then, it is important to protect existing habitat on

Key Largo by expanding Crocodile Lakes National Wildlife Refuge to

include all of hammocks L(1)6, 9, 10 B, 11, 13, and 14 on the east

side of Highway 905. The narrow strip of hammock L(2) 1 on the

west side of Highway 905 has abundant torchwood in places, but by

comparison with the other hammocks, may not be broad enough to

support a viable population of Schaus Swallowtails by itself

without association with hammocks east of Highway 905 (cf.

recommendations in the Recovery Plan, criterion 1131 on page 23

and page 46, U.S. Fish & Wildlife Service, 1982, where Hammocks 6

and 9 were omitted on page 23 but included on page 46 in lists of

essential habitat areas.)

It would also be feasible to reintroduce the Schaus

Swallowtail into northern Key Largo hammocks from the larger

populations in Biscayne National Park. In meeting this Recovery

plan recommendation (step 13, p. 31, USF&WS, 1982) to reestablish

ognceanus colonies in appropriate areas within its historic range,

sites containing historically suitable habitat will have to be

secured (steps 1311 and 1312, p. 31) and a decision will have to

- 24 -

be made regarding initiation of captive propagation versus

transfers of wild adult individuals. From past experience with

breeding rare butterflies, it would seem safer and more practical

to remove a limited number (10-12) eggs or young larvae from the

wild on Elliott or Old Rhodes Keys and use these as the basis for

a breeding stock, than to remove an equivalent number of adults

from the wild and transfer them between islands. A single female

swallowtail is capable of laying over 100 eggs, and the close-to-

95% loss in nature between egg and adult stages (USF&WS, 1982) is

due to many selective factors such as parasitism and predation

which can be excluded in the laboratory. Wild adult transfers

have not been successful with other butterfly species as regards

new colony establishment. However, transfers of eggs and larvae

from montane Wyoming populations of the checkerspot nymphalid

butterfly Euehptdrya gyljgttii south to locations in the central

Colorado mountains have resulted in the firm establishment of at

least one Colorado population (Holdren and Ehrlich, 1981), and

transfers of pupae have been used in south Florida to establish

many new populations of the Florida Atala lycaenid butterfly,

Eumaeus ata~a, in the past several years (R. Boender and P. Henry,

unpublished). Adult transfers in the past have not successfully

established the Atala butterfly in the same Everglades National

Park areas (Rawson, 1961).

The problem with initiating reestablishment of the Schaus

Swallowtail in the northern Key Largo area is that extensive

aerial spraying of mosquito insecticides on the keys during the

past decade may be responsible for the precipitous decline in

numbers of the butterfly there. In this respect, then, it is

- 25 -

recommended that: (1) captive propagation of ponceanus be

initiated with the aim of reintroduction into areas that are not

being sprayed, or that spraying by the Monroe County Mosquito

Control District be suspended in the areas where the butterfly is

presently found or is to be released; (2) pesticide testing

experiments be initiated with the parental subspecies of the

Schaus Swallowtail, Eailio ACisodgemus ACrstodeysU, collected and

bred from material taken in the Dominican Republic on the island

of Hispaniola, and assessment of the relative toxicity to the

butterfly of each component of the complex spray mixture be


Finally and most clearly, the tropical hardwood hammock in

appropriate areas and quantities on Key Largo will need to be

preserved in order to attain any of these objectives, and to

insure the continued existence of the endangered Schaus

Swallowtail outside its present reduced range (1984) in Biscayne

National Park and one area on Key Largo. A substantial side

benefit of this course would be to have this distinctive large

butterfly in areas readily available to public observation during

its flight season, an example of an endangered species brought

back from the edge of extinction by sound environmental policies.


Brown, L. N. 1973. Populations of EPagio andraemon bonhotei
Sharpe and Paegili aristogdemus RBncgan Schaus (Papilionidae)
in Biscayne National Monument, Florida. J. Lepid. Soc.
27 (2): 136-140.

Brown, L. N. 1974. Haven for rare butterflies. National Parks
and Conserv. Mag., July 1974: 10-13.

Covell, C. V. Jr. 1976. The Schaus swallowtail: a threatened
subspecies? Insect World Digest 3 (5): 21-26.

Covell, C. V. Jr. 1977. Project Ponceanus and the status of the
Schaus swallowtail (EPailig aCristdemus EOg nanus) in the
Florida Keys. Atala 5 (1): 4-6.

Covell, C. V. Jr., and G. W. Rawson. 1973. Project ponceanus: A
report on first efforts to survey and preserve the Schaus
swallowtail (Papilionidae) in southern Florida. J. Lepid.
Soc. 27: 206-210.

Covell, C. J., Jr. 1982. The Florida Trip, May 19-21, 1982.
Kentucl' Lepidonteriltv 8 (2): 3.

Grimshawe, F. M. 1940. Place of sorrow: the world's rarest
butterfly and Matecumbe Key. Nature Mag. 33: 565-567, 611.

Henderson, W. F. 1945a. Pa~oili aristodemus ognceana Schaus
(Lepidoptera: Papilionidae). Entomological News 56: 29-32.

Henderson, W. F. 1945b. Additional notes on eagiiig ari2tfgdemus
oggceana Schaus (Lepidoptera: Papilionidae). Entomological
News 56: 187-188.

Holdren, Cheryl E., and Paul R. Ehrlich. 1981. Long range
dispersal in checkerspot butterflies: transplant experiments
with EuhydCy&a giletgtibi Oecologia(Berl.) 9, 50: 125-129.

Little, E. L. 1978. Atlas of United States Trees. Volume 5:
Florida. U.S.D.A.

- 27 -

Miller, L. D. 1975. Threatened status for two butterflies?
Field Museum Nat. Hist. Bull. 1975: 15-18, 22.

Rawson, George W. 1961. The recent rediscovery of EumaSeu atala
(Lycaenidae) in southern Florida. J. Lepid. Soc. 15 (4):

Rutkowski, F. 1971. Observations on Pa~ilio aCistodemus
gonQfanus (Papilionidae). J. Lepid. Soc. 25: 126-136.

Schaus, W. 1911. A new EPa~geg from Florida, and one from Mexico
(Lepid.). Entomol. News 22: 438-439.

U.S. Fish and Wildlife Service. 1982. Schaus Swallowtail
Butterfly Recovery Plan. U.S. Fish and Wildlife Service,
Atlanta, Georgia. 57 pp.

- 2S -


Figure 1. General map of south Florida mainland, principal keys
in Biscayne National Park, and the Florida Keys, including the
historic range of the Schaus Swallowtail (Paeilig aristodems
eonceanus) from Miami to Lower Matecumbe Key and Key West.

Figure 2. Tropical hardwood hammocks (numbered after U.S. Fish
and Wildlife Service, 1982, Figure 3 maps) and other habitat
types on northern Key Largo, Monroe County, Florida. Specific
locality records of museum and private-collection specimens of
Schaus Swallowtails, where more detailed information than
solely "Key Largo" labels was available, are shown by black
stars. The 1984 record is shown by a white star.

Figure 3. Map of principal keys in Biscayne National Park, Dade
County, Florida. Locations of 1984 populations of the Schaus
Swallowtail on Elliot, Old Rhodes, and Totten Keys are shown
by white stars.

- 29 -




---ower Matecumbe Key
SLAKE NWR ""--Long Key


Figure 1


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51 - ;

..... 1984

CROSS EYi : < A C "'

I 'i (southernmost record -
,.... . - 9 o
'--. . .. - ., . . . _- " . " =" .. .- .." "

S0 2000 4000 8000r2000 FEET
.-* . . - ,

-3 1-

- � - ... .- . . ... .
..A-. ,. - 9, 0 .....

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, ._ 1 -. 7 1 :

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21. 2 72(7 26 29

I 27

.. . . ...- * . . , - . .. - . . ... . . . .. ..... .. I r.:,- . .

"- . ";, �-"' ",'"- ":'-: -"-: C I LED 'IN..� : - . -IV I " ...... :

28 3

. .. - .-: -. - A T A N T . .-- " -. - M .
U33 A j 4-

ANG L /S CR r*
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---_.> -.."--"--.-


. Figure 2b.


-. , ,,. * .- . .:,.



Scale: 1:71,500 '

a i i 1 Kilomme /
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i ee



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Figure 3.

2 Broad Creek

1 Angelfish Cie.k


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L Adellf
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gar Creak\






Figure 1.

Figure 2.

Schaus Swallowtail (Papilio aristodemus ponceanus), adult male,
in the wild on Petrel Point trail, Elliott Key, Biscayne National
Park, Florida, on May 10, 1984, showing typical basking and
resting posture.

Schaus Swallowtail male resting momentarily on torchwood
branch within a hardwood hammock on Elliott Key.

Figure 3. Torchwood (Amyris elemifera) on northern Key Largo in May,
1984. This is the preferred larval hostplant for the Schaus

Figure 4.

Figure 5.

The distinctive underside pattern of Schaus Swallowtail (an
adult male). This also illustrates how the adults may be
lightly held without damage for a short time, in order to
record wing condition, sex, and distinguishing marks.

In the same tropical hardwood hammocks where Schaus Swallowtails
fly in May and June, this second distinctive tropical species,
the Florida Purple Wing (Eunica tatila tatislista) flies in
August and September in fair numbers. It is the only member of
its group that is resident in the United States, and its habitat
on the Florida Keys is seriously threatened by development along
with the same factors affecting Schaus Swallowtail. Its life
history is unknown.

Figure 6. Interior of a tropical hardwood hammock on Tottem Key in
Biscayne National Park, where both Schaus Swallowtail and
the Florida Purple Wing are found. The adult Schaus Swallowtails
normally stay within five feet of the ground during the their
slow, deliberately cautious flight; they avoid obstacles such
as fine branches and spider webs by flying slowly, backing off,
maneuvering up or sideways slowly, and then proceeding.





~~ I~_

FIGURES 7 - 11

Figure 7. Adult male (left) and female specimens of Schaus Swallowtail,
Papilio (Heraclides) aristodemus ponceanus Schaus: dorsal
surface. (Mounted specimens from the Allyn Museum of Entomology,
Sarasota, Florida.)

Figure 8. Ventral surface of male (left) and female Schaus Swallowtail
specimens shown in Figure 7.

Figure 9. View of mature hardwood hammock on Old Rhodes Key on June 4,
1984, when the Schaus Swallowtail adult population was at
maximum flight here.

Figure 10. The second recorded larval hostplant for Schaus Swallowtail:
Wild Lime (Xanthoxylum fagara), photographed on Elliott Key
on May 10, 1984.

Figure 11. The primary larval hostplant for Schaus Swallowtail: Torchwood
(Amyris elemiferal showing the lighter new growth at the top of
a shoot. The new growth each spring (and later times following
rains) is the preferred oviposition site of the females.





~ (~T J
4w,. I


FIGURES 12 - 17

Figure 12.

Adult female of the Giant Swallowtail, Papilio cresphontes
Cramer: dorsal surface. (Mounted specimen from Gainesville,
Alachua County, Florida; same phenotype as in south Florida.)

Figure 13. Adult male of Giant Swallowtail: dorsal surface.

Figure 14. Ventral surface of Giant Swallowtai, adult female.

Figure 15.

Figure 16.

Figure 17.

Ventral surface of Giant Swallowtail, adult male. The adults
of the Giant Swallowtail fly in overlapping broods throughout
the year in the same hammocks where the single annual brood
of Schaus Swallowtail flies.

The primary larval hostplant of the Giant Swallowtail, Papilio
cresphontes, in the hammocks where it flies with Schaus
Swallowtail, Papilio aristodemus ponceanus, is true wild Key Lime,
Citrus aurantifolia, which has naturalized in the hammocks of
south Florida and the Florida Keys. Other naturalized species
of Citrus are also used by the Giant Swallowtail. Apparently,
the two swallowtails do not compete for larval foodplants
extensively, although Giant Swallowtail eggs and larvae may be
found frequently on the Wild Lime (Xanthoxvlum) used secondarily
by the Schaus Swallowtail. The extent of this foodplant overlap,
as well as competition for adult nectar sources, will be analyzed
in the proposed research.

The Florida Atala, Eumaeus atala florida Rober, is a very rare
lycaenid butterfly endemic to south Florida and the Keys. It
was believed to have become extinct by the early 1960's, but
several colonies were rediscovered in the late 1970's and during
1983 and 1984, the butterfly reappeared in the Miami urban area,
using cycads (its larval host) in nurseries and home gardens as
hosts! It occurs in shady tropical hardwood hammocks in its
Florida distribution, including (1984) the Schaus Swallowtail
habitat on Elliott Key and on northern Key Largo. The preservation
of tropical hardwood hammocks for Schaus Swallowtail populations
should also aid Florida's other unique tropical butterfly species
such as the Florida Atala and the Florida Purple Wing (Figure 5).


tt4 .. -

~II ~~_~~1~1__