Schaus Swallowtail Emergency Action: Questions and Answers
Female Schaus swallowtail butterfly. Photo used with permission of: Jaret C. Daniels, Ph.D, Florida Museum of Natural History. Download.
1. Why is this emergency action necessary?
Numbers reported this flight season have been alarmingly low and without intervention, extinction of this subspecies is possible. Just three to five individuals have been noted to date in survey efforts this season and only one was a female. All butterflies were detected in Biscayne National Park, which is considered a stronghold for the subspecies because it supports intact native habitat and is not subjected to insecticide application for mosquito control.
2. Who/what agency was conducting the surveys for these butterflies and noticed that so few were around this year?
Those surveys were conducted by the University of Florida and the North American Butterfly Association with the assistance of the National Park Service and the Florida Fish and Wildlife Conservation Commission. Funding was provided under a contract from the U.S. Fish and Wildlife Service.
3. If this species has been protected since 1984, is this emergency action an indictment against what you’ve been doing to protect this species since then?
We’ve conducted several initiatives over the years, including a captive breeding program in the mid-1980s and late 1990s, aimed at conserving these butterflies. Unfortunately, factors such as pesticide use, habitat destruction, droughts, hurricanes and illegal collection have hindered our efforts. This is an ongoing, challenging effort against the uncertainty of Mother Nature.
4. Doesn’t collecting them put the few that are left at increased risk?
No. It’s done by professionals using extreme care and proven methods. Adult female butterflies will be gently netted, marked, and temporarily confined in a portable 12’ x 12’ mesh cage on site (natural habitat). Females will be allowed to fly freely in the cage and lay their eggs on the available host material. The cage and its residents will be regularly monitored and all available new eggs will be removed several times a day. Females will be confined for up to 4 days and then subsequently released back into the natural habitat. This protocol would minimize any impact to the wild population as females continuously produce new eggs during their life. All collected eggs will be labeled according to the adult butterfly number, and a wing fragment sample – such as the tip of a hind wing tail, will be taken for as a genetic voucher. All eggs will be maintained in small vials and transported back to the University of Florida in Gainesville for rearing.
5. So, when did this emergency collection initiative start and have you collected any Schaus Swallowtails? Who’s actually doing the collecting? How long will this initiative continue?
It started on June 8, 2012. So far, none have been collected. The field work is primarily being conducted by investigators from the University of Florida McGuire Center for Lepidoptera and Biodiversity, with assistance from the National Park Service. This work will continue at least through the end of June, when the flight season for this subspecies typically ends. Additional surveys will be performed in the autumn, in case a second flight occurs.
6. Has captive breeding for this species been tried before? Did it work? If not, what are the odds it could work this time?
The Florida Fish and Wildlife Conservation Commission (formerly known as the Florida Game and Fresh Water Fish Commission) funded a captive breeding program from 1985-1988 and the U.S. Fish and Wildlife Service funded UF to conduct captive rearing and reintroductions during the mid to late 1990s, both within Biscayne National Park and northern Key Largo. These efforts were largely successful in increasing Schaus numbers. We’re considering a similar, smaller-scale project with the university right now. In addition, we have funded a major habitat enhancement project within BNP designed to replace exotic vegetation with important hardwood hammock species, including host plants of the Schaus swallowtail.
7. How can the general public help you save these butterflies?
They can plant native flowering plants in their gardens to create habitat where butterflies can feed and nest. People could also reduce their use of pesticides by encouraging beneficial insects for pest control. The general public can learn more about helping imperiled butterflies by joining a local chapter of the North American Butterfly Association. In addition, if anyone spots what they believe is a Schaus swallowtail butterfly, they can report it to the U.S. Fish and Wildlife Service’s office in Vero Beach immediately by calling (772) 469-4323.
8. How much is being spent on this emergency action?
The surveys are being conducted under a two-year contract to the University of Florida from the U.S. Fish and Wildlife Service valued at about $25,000. The captive rearing project being discussed should cost about $8,000.
9. What’s being done at BNP to help these butterflies survive?
Biscayne National Park does not allow mosquito spraying and actively controls exotic vegetation that threatens the butterfly's habitat.
10. How long will you look for female Schaus swallowtail butterflies? And what if you don’t collect any?
Their current flight season lasts until mid-June. We’ll continue until at least then. It’s important to note that the pupae can last 1-3 years. This is important because it might be years before we know if any Schaus emerge. In other words, even if we don’t collect any this year and don’t see any next year, it might not mean the species has gone extinct.
11. If numbers of the Schaus swallowtail were low in the past two years why did you wait until last week to authorize the capture/propagation project?
While 2010 and 2011 were particularly dry, the Schaus swallowtail pupae can lie dormant for one to three years. Florida’s recent dry season had moisture enough that researchers expected to see a flight of adult butterflies that equaled or exceeded the 2011 count. Researchers immediately requested the emergency capture and propagation authorization when so few adult butterflies were counted during the 2012 annual survey from mid-May to mid-June.