Heraclides aristodemus ponceanus

Overview

The Schaus swallowtail butterfly was listed as a threatened species in 1976 due to the decline of its tropical hardwood hammock habitat, mosquito control practices, and over collecting. Following continued population losses, the butterfly's status was changed to endangered in 1984. Since then, Hurricanes Andrew in 1992 and Georges in 1998 severely damaged Schaus habitat, and butterfly numbers plummeted as low as a few dozen.

Description

The Schaus swallowtail butterfly is a member of the family Papilionidae. It is a large, dark brown butterfly, with a wingspan of 3 ¼–3¾" (8¼–9½ cm), which closely resembles the giant swallowtail (Papilio cresphontes) but has solid dark brown tails with a yellow border and a narrower yellow wing band. The ventral hindwing has a distinct, broad rust-colored band bordered distally with blue. The sexes are similar but males have yellow-tipped antennae.

Life History

The butterfly occurs exclusively in subtropical dry forests (hardwood hammocks) including areas that were formerly cleared and farmed, but have since regrown. Adults feed on the nectar from blossoms of guava (Psidium guajava), wild tamarind, and cheese shrub (Morinda royoc). The larvae feed on the tender new growth of the pioneering shrubs torchwood (Amyris elemifera) and wild lime (Xanthoxylum fagara)

Distribution

The Schaus swallowtail butterfly's distribution is limited to tropical hardwood hammocks and is concentrated in the insular portions of Miami-Dade and Monroe counties. Once ranging from the south Miami area down to Lower Matecumbe Key, its range has shrunk to the upper Florida Keys, where it is now found from Key Biscayne Park to northern Key Largo and Upper Matecumbe Key.

Conservation Status

The high point of 1200 to 1400 Schaus butterflies reached in 1996 and 1997 following three years of reintroductions, with normal rainy seasons in those and preceding years, and the additional input of released adults, has not been reached since 1997, due to the severe drought that began in 1998 in south Florida and which has continued to the present time in (J. Daniels, University of Florida, personal communication 1999). The results of 2002 field census data estimate the current population to be between 190-230 adults.

Conservation Needs

According to the USFWS's Recovery Team recovery actions for the butterfly should focus on acquiring additional hardwood hammock habitat and protecting those areas and existing hammock from development. In addition, habitat improvement, through the planting of hundreds of wildlime trees, is being conducted within selected colonies on Key Largo.

Working with landowners

In September 2001 the USFWS and Cheeca Lodge, located on Florida's Matecumbe Key, signed a safe harbor agreement to benefit the Schaus swallowtail. The 27-acre golf resort will team with the University of Florida's McGuire Center for Lepidoptera Research to create habitat for the endangered butterfly. The National Fish and Wildlife Foundation contributed $55,000 to help fund this work.

The USFWS is encouraging other Florida landowners to enter safe harbor agreements on behalf of the Schaus swallowtail butterfly. Additional successful cooperative restoration and environmental education programs at both the Crocodile National Wildlife Refuge and the Key Largo Anglers Club within critical habitat areas on the northern end of Key Largo have resulted in the planting of over 1500 native larval host and adult nectar sources to date.

Education

Education sheets available at zoological facilities (e.g. zoos, aquariums, botanical gardens with butterflies, butterfly houses, natural history museums) or events at which BFCI partners participate are a valuable way to disseminate information about imperiled butterflies.

When schools and other youth organizations study biodiversity and species extinctions they typically use examples of charismatic megafauna (e.g. bald eagles) or exotic creatures from the tropics. However, vulnerable species found within the state or ecoregion in which students live provide an excellent opportunity to develop curricular materials with a direct link to the students' home region. In addition to classroom studies, students may be able to visit sites to see the butterflies, as well as talk to the scientists and land managers involved in the species' conservation.

Educational activities that school students and community members could do include:

• studying butterfly (insect) life stages;
• researching the special habitat needs of the Schaus swallowtail;
• corresponding or meeting with the biologists managing current Schaus swallowtail sites;
• visiting Schaus swallowtail sites during adult flight season;
• visiting captive breeding programs;
• assisting scientists with on-site habitat management;
• propagating and growing host plants for planting at butterfly sites or use in captive breeding programs; and
• writing letters to decision makers to ensure that the Schaus swallowtail receives adequate resources and protection.

Research

Scientists from the McGuire Center for Lepidoptera Research at the University of Florida continue to annually monitor Schaus swallowtail population at all known south Florida colony sites.

Captive Rearing

The captive propagation and reintroduction efforts to date have been quite successful. The captive colony was started in May-June 1992, prior to the hurricane, when about 100 eggs were obtained from wild females briefly caged on Elliott Key in Biscayne National Park. This highly fortuitous timing allowed for the successful captive production of 31 diapausing pupae by July 1993, and the first successful mating of captive adults (via hand-pairing) in March 1993.

Eggs produced from these captive females were increased by additional eggs brought from Adams Key in Biscayne National Park in June 1993 and produced 49 healthy pupae, the nucleus of the 1994, 1995 and 1996 captive propagation programs (Emmel et al, 1993, 1994a, 1994b, 1998a, 1998b) for the 1995, 1996, and 1997 reintroduction releases. In Spring 1995, the first reintroduction efforts were initiated. A total of 764 pupae were released in seven sites, from the Deering Estate in south Miami on the mainland to Key Largo.

Despite heavy predation by migrating warblers, successful adult emergence and subsequent reproduction was identified at all sites, and represented the first time since 1924 that the Schaus Swallowtail was found on the South Florida mainland. The subsequent 1996 and 1997 releases of 500 and 209 adult butterflies enhanced existing population numbers and established, directly or indirectly (via local movements), six additional colonies in the Upper to Middle Keys.

Recovery Plan

Schaus Swallowtail butterfly in the Multi species Recovery Plan for South Florida Revision (359KB pdf) (May 18, 1999).

The objective of the 1999 Schaus swallowtail recovery plan is to delist the species. This objective will be achieved when further loss, fragmentation, or degradation of suitable, occupied habitat within the butterfly's historic range in the Upper Florida Keys and Miami-Dade County has been prevented; when breeding sites of the Schaus swallowtail butterfly have been protected from mosquito spraying; when mosquito spraying in other areas used by the Schaus swallowtail butterfly has been reduced by 90 percent; when all suitable, occupied habitat on priority acquisition lists for the Schaus swallowtail butterfly is protected either through land acquisition or cooperative agreements; when the hardwood hammocks that form the habitat for the Schaus swallowtail butterfly are managed, restored, or rehabilitated on protected lands; and when stable populations of the Schaus swallowtail butterfly are distributed throughout its historic range. These populations will be considered demographically stable when they exhibit a rate of increase (r) equal to or greater than 1.

Recovery Priorities

Species-level Recovery Actions

Determine the distribution and status of wild Schaus swallowtail butterfly populations.

• Determine the status of wild butterflies within current range
• Determine the status of captively reared Schaus swallowtail butterflies
• Survey natural butterfly habitat and determine habitat characterization and use by both wild and captive-bred butterflies
• Determine the status of habitat at release sites
• Survey other butterfly populations in occupied Schaus swallowtail butterfly habitat
• Maintain and improve the GIS database for butterflies information
• Conduct presence and absence surveys for Schaus swallowtail butterfly in suitable habitat throughout the Florida Keys

Protect and enhance existing, wild populations of the Schaus swallowtail butterfly.

• Assign a biologist responsibility for implementing recovery actions for the threatened or endangered species of the Upper Florida Keys and Miami-Dade County (Deering Estate and Biscayne NP).
• Utilize federal regulatory mechanisms for protection.
• Provide Schaus swallowtail butterfly information to federal, state, county, and city agencies.
• Reduce human-related mortalities of Schaus swallowtail butterflies. Mortality is primarily a result of habitat modification such as clearing for residential and commercial construction, fires, introduction of pesticides and other hazardous chemicals, and deaths from vehicular collisions, predators, parasites, and collectors.
• Develop a captive propagation protocol for the Schaus swallowtail butterfly and implement as warranted. Methods to breed and raise Schaus swallowtail butterflies in captivity have been established.

Conduct research on the biology and life history of the Schaus swallowtail butterfly.

• Determine if the total population size is large enough to prevent functional extinction and genetic extinction.
• Determine the number of subpopulations necessary to maintain a stable or increasing population.
• Examine factors that affect the abundance and distribution of the Schaus swallowtail butterfly.
• Evaluate the effect of releasing captive-bred butterflies into the wild the persistence of the Schaus swallowtail butterfly.
• Investigate the effects of insecticides used for mosquito control on surrogate species closely related to the Schaus swallowtail.

Monitor the status of the Schaus swallowtail butterfly and its habitat.

• Monitor demographic parameters including sex ratios, age class structure, survivorship, home range size, and dispersal distance.
• Continue long-term monitoring of the Schaus swallowtail butterfly.

Increase public awareness and stewardship. Inform the public (especially butterfly collectors) about the butterfly, its protections under Federal law, and its importance as an integral part of the ecosystem.

Establish reclassification criteria. Develop measurable reclassification criteria based on factors that result in a stable or increasing population including total population size, number of subpopulations, sex ratio, age structure, habitat condition and availability, and level of threats.

Habitat-level Recovery Actions

Prevent further loss or degradation of existing Schaus swallowtail butterfly habitat.

• Acquire unprotected Schaus swallowtail butterfly habitat.
• Protect and manage Schaus swallowtail butterfly habitat.

Restore both suitable occupied and unoccupied Schaus swallowtail butterfly habitat.

• Restore Schaus swallowtail butterfly habitat. Restore Crocodile Lake NWR habitat and support the restoration of habitat on State and county lands.
• Improve habitat by planting or encouraging native plant species.
• Improve habitat by conducting selective trimming.
• Remove exotic vegetation.
• Remove trash debris.

Conduct research to determine habitat needs for the Schaus swallowtail butterfly. Investigate how butterflies use different habitat components for survival.

Monitor the status of Schaus swallowtail butterfly habitat and examine ecological processes.

• Conduct long-term monitoring of habitat patches.
• Monitor primary and edge forest habitat.
• Monitor ongoing and proposed habitat restoration efforts.

Increase public awareness of Schaus swallowtail butterfly habitat and instill stewardship. Conduct workshops with the public to inform private landowners on appropriate management practices to preserve Schaus swallowtail butterfly habitat.

For more information

• USFWS Contact: Lee Andrews, South Florida Ecological Services Field Office, 1875 Century Boulevard, Atlanta, GA 30345, Phone 404-679-7217.
• For information on research contact: Jaret C. Daniels, Ph.D., Assistant Director for Research, McGuire Center for Lepidoptera Research, University of Florida, Gainesville, FL 32611, Phone 352-392-5894.
• For information on safe harbor agreements contact: Michael Bean, Environmental Defense, 1875 Connecticut Avenue, NW, Suite 600, Washington, DC 20009, (202) 387-3500

References and Resources

• Emmel, T.C. 1985. Status survey of the Schaus swallowtail in Florida in 1984. Technical report No. 145, Florida Cooperative Fish and Wildlife Research Unit, University of Florida; Gainesville, Florida.
• Emmel, T.C. 1986a. Status survey and habitat requirements of Florida's endemic Schaus swallowtail butterfly. Florida Game and Fresh Water Fish Commission, Final Report GFC-84-028; Tallahassee, Florida.
• Emmel, T.C. 1986b. Pesticide effects on the survival of the Schaus swallowtail butterfly. Final report to Elizabeth Ordway Dunn Foundation, Inc. University of Florida, Gainesville, Florida.
• Emmel, T.C. 1988. Habitat requirements and status of the endemic Schaus swallowtail in the Florida Keys. Florida Game and Fresh Water Fish Commission, nongame Wildlife Section; Tallahassee, Florida.
• Emmel, T. C. 1995a. Designated species management plan for the reintroduction of the Schaus swallowtail butterfly in the Florida Keys. University of Florida, Gainesville, Florida.
• Emmel, T.C. 1995b. Captive propagation and experimental reintroduction of the Schaus swallowtail in the Florida Keys. Interim status report submitted to the U.S. Fish.
• USGS Butterflies of North America: Schaus swallowtail
• USFWS Schaus swallowtail page
• Schaus Swallowtail butterfly in the Multi-species Recovery Plan for South Florida Revision (359KB pdf) (May 18, 1999)

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Classification

Federal Endangered Species (Federal Register: 49:34501; August 31, 1984)

State Status

Endangered.

Range

FL

Critical Habitat

None designated

Acknowledgement

This profile was prepared by the Xerces Society for the Butterfly Conservation Initiative.