The Schaus Swallowtail

*Previously published in Wild Life: The Institution of Nature, by Irus Braverman. © 2015 by the Board of Trustees of the Leland Stanford Junior University. Published by Stanford University Press. Used by permission of the publisher.
**The featured image (courtesy of Thomas C. Emmel), taken from the book, shows Schaus swallowtail butterfly number 158, held by Thomas Emmel in 2013. Upon emergence from their sac, every captive adult is marked with a number on the underside of the wing. Schaus swallowtail 158 was marked on the day of her or his first capture, released, and then re-captured several days later.

Today, in this second excerpt from Irus Braverman’s book, the challenges of saving an endangered species are brought into focus. The author would like to dedicate this post to the memory of Thomas Emmel, who passed away in 2018. His passionate work continues to inspire and guide Lepidoptera conservationists the world over.

By Irus Braverman

Thomas Emmel, now a retired University of Florida professor, directed the captive breeding project for more than twenty years. Establishing the program cost $50,000 (“these butterflies are damn expensive,” says Kierán Suckling5), obtained largely from federal sources. Despite the fact that the USFWS recognized the importance of captive propagation, the agency’s preference toward in situ conservation was clearly emphasized throughout. Accordingly, the 1999 federal recovery plan stated: “All future efforts to captively breed Schaus swallowtail butterflies should be conducted in situ in as natural conditions as possible. Preferably, butterflies should be raised in enclosures in suitable habitat within the historic range. Captive propagation efforts closer to release sites are preferable for many species. This would limit transport time and possible difficulties in achieving a successful release.”6 Emmel describes USFWS’s strong preference for in situ: “The Fish and Wildlife Service and the National Park Service were so hyper about the relatively small population [of these butterflies] that was there even before the hurricane that they didn’t want females or even males handled much. [So] they didn’t want us to bring them up to [the university facility in] Gainesville where we could have done a great deal of work for the full lifetime of the female in captivity.”7 Instead, Emmel and his staff had to keep the females in “big netting tents over the torchwood trees. And each butterfly had to be in a separate tent.” Still, Emmel tells me, the researchers were able to track the eggs that the females had laid in the tent and to “keep a complete notebook of all the eggs and the closest subsequent larvae and to trace them back to the appropriate females. . . . Then, with the next generation in captivity, we out-crossed for maximum genetic diversity.”8 The breeding progressed well and reintroductions commenced in 1995; by 1997, thirteen new in situ populations were established.

The reintroductions were not by any means easy. In the early 1990s, the University of Florida had thousands of butterfly pupae ready for release. But when Emmel and his team began asking park managers for permission to release the butterflies on their land, they were met with a resounding refusal or, at best, resistance. Here, from Emmel’s account:

Nobody wanted them! The local land managers said: “No, we know that the Schaus swallowtail once included this area, but we don’t want any release there  because we have so much to handle now with paperwork and we don’t want to    deal with an endangered species being reintroduced and all that.” And here we    started with the naive viewpoint that everyone would welcome the revival of the endangered species, and provide a new point of interest for visitors to that area, et cetera. But probably the greatest shock in those years was that nobody wanted it, it was an orphan. An endangered species had become an orphan.9

“We could keep it in the orphanage up here in Gainesville, but we couldn’t find any foster parents,” Emmel continues. It was partly the amount of intense management the pupae needed that triggered the reluctance toward swallowtail reintroductions on the part of land managers. But even the adult butterflies, Emmel says, were rejected by them. “It took us until 1995 to finally get several land managers to agree to accept it,” he tells me. At last, their persistence had paid off and “eventually, we got them released as far south as the southern middle Keys.”10

The “trick” that helped persuade enough landowners to open their land to swallowtail reintroductions, according to Emmel, was the legal redesignation of the populations destined for release in sensitive areas as “non-essential experimental populations.” The reintroductions ended up progressing so well that the species’ geographic range quadrupled from what it had been twenty years before Hurricane Andrew. Due to these successes, in 1999 the USFWS declared the Schaus population stable and stopped its funding of Emmel’s captive breeding project.11

Although Emmel managed to sustain the captive butterfly population at the university facility for a couple of years with private funding, this funding quickly dried up. In his words:

In 2000 we ran out of money. We couldn’t afford to pay even the poor students, [whom we had hired] year after year on a prayer and a promise. So we wrapped it up and just shut down the colony. That was what we were forced to do, believe it or not. If land managers don’t want them released in their area, . . . or if the agency that controls the breeding permits won’t give you permission [to breed], or if the state doesn’t approve it for one reason or another—then you’ve got trouble. . . . It’s astonishing. The inside story is just almost beyond belief.12

Shutting down the colony meant, in this context, letting the last of these endangered butterflies die out without producing offspring. How difficult this was for Emmel was evident from his tone of voice as he recounted this episode to me. “Working with endangered species is very much a roller coaster—emotionally, psychologically, and physically,” he told me.

You have periods of intense fieldwork under extremely arduous conditions: the temperature is 105 degrees, humidity near 100 percent, billions of salt marsh mosquitoes so bad that you’re wearing ant nets and mosquito jackets to keep them off you, and you’re working for weeks out there marking and releasing, trying to understand these butterflies. You’re doing captive propagation back here year-round with a bunch of dedicated student helpers who are doing much of the actual work. And then you go down there after a couple of years of no support and no releases and you see that the population has dwindled.13

Unfortunately, drought years followed, and the Schaus swallowtail population experienced a dramatic decline.14 In 2011, Emmel documented that the population had diminished from forty-one butterflies to five, with only a single female.15

As a result, in June 2012 the USFWS issued an “emergency authorization” to collect and captively breed Schaus swallowtail butterflies.16 However, no swallowtail butterflies were found that year. This led to a massive critique of the USFWS by the conservation community—both for its initial decision to stop captive breeding and for its belated decision to resume it. One butterfly expert was quoted saying: “The government owned this bug, and they dropped the ball.”17 “It’s frustrating to have your hands tied . . . by bureaucratic indecision that lets things drift so far downward,” Emmel remarked at the time.18 Reflecting on the program a few years later, Emmel tells me: “with all endangered species projects the funding is always erratic. You can always expect them to be almost always late, or they’ll skip a year or two or three thinking that you can just start it up again a couple of years later. . . . It’s highly variable. What’s needed is greater continuity in support, a commitment . . . that endangered species research should be continued or guaranteed in some way.”19

A similar, albeit less well-documented, story is currently unfolding in the case of the Lange’s metalmark butterfly (Apodemia mormo langei).20 “It’s ridiculous,” Kierán Suckling comments. “The captive breeding programs in both cases should never have been canceled.”21 Such stories, and many others, demonstrate the fraught and codependent relationship between in situ and ex situ conservation and the dramatic impact of decisions to move animals—or not to move them—from in situ to ex situ and back.

Lange’s metalmark butterfly. Photo: Pacific Southwest Region USFWS, CC BY 2.0, via flickr (this image is not included in the original publication).

As for the Schaus swallowtail, expanded late-season surveys in 2013 found thirty-one individuals.22 One hundred eggs were collected from four females that year and propagated in captivity by Emmel and his team (Figure 1). By mid-2014, the butterflies who hatched from the original hundred eggs—known as “founders”—produced approximately one thousand larvae, and Emmel’s team planned to reintroduce two to three hundred adults into the wild.23


1. The Xerces Society for Invertebrate Conservation, “Swallowtails: Schaus Swallowtail (Heraclides aristodemus ponceanus),”

2. United States Golf Association, “Turfgrass and Environmental Research Online,” June 1, 2004,

3. Craig Pittman, “Endangered Schaus Swallowtail Butterfly May Be All but Gone,” Tampa Bay Times, August 30, 2012.

4. United States Golf Association, “Turfgrass and Environmental Research Online.”

5. Kierán Suckling (director, Center for Biological Diversity), e-mail communication, May 11, 2014.

6. Schaus Swallowtail Butterfly (Heraclides aristodemus ponceanus), Multi-Species Recovery Plan for South Florida,

7. Thomas C. Emmel (founding director, McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History), interview by author, telephone, June 5, 2014.

8. Ibid.

9. Ibid.

10. Ibid.

11. Pittman, “Endangered Schaus Swallowtail.”

12. Emmel, interview.

13. Ibid.

14. Pittman, “Endangered Schaus Swallowtail.”

15. National Park Service, “Schaus Swallowtail Emergency Response, Biscayne N.P.,”

16. Ken Warren, Elsa Alvear, and Jeffrey Olson, “National Park Service Release,” June 13, 2012,

17. Pittman, “Endangered Schaus Swallowtail.”

18. Ibid.

19. Emmel, interview.

20. Suckling, e-mail communication.

21. Ibid.

22. Biscayne National Park, “Schaus Swallowtail Sighting Alert,” Facebook post, August 16, 2013,

23. Jenny Staletovich, “Rare Butterflies Fight for Survival in South Florida,” Miami Herald, May 20, 2014,

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