STANFORD
UNIVERSITY PRESS
  



Wild Life
The Institution of Nature
Irus Braverman

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Puerto Rican Crested Toad

The Natural Resource Secretary called me to his office to fire me. “Miguel, why do you worry so much? Why do you get in trouble, Miguel? Why do you bring so many problems, Miguel? Please, Miguel, why [do] you care?” And I tell him, “Look, when my granddaughter [will] ask me ‘What’s a crested toad?’ and I’m going to tell her that they don’t exist anymore, and I was the Biologist of Guánica in charge of that animal and I let them be killed—what [will] I say? . . . And so I tell him: “We are all Puerto Rican, but most Puerto Ricans haven’t been born yet. So we have to leave this for our grandchildren and grandchildren and grandchildren.” And the guy started, he was like this, he said: “You make me cry,” he told me.
—Miguel Canals, Forest Ranger, Guánica State Park, Puerto Rico1

The Puerto Rican crested toads (Peltophryne lemur)—the only “native” toads of Puerto Rico and the Virgin Islands—are small, nocturnal amphibians with a unique upturned nose (crest—hence the name) that gives their head the look of a foreshortened baby caiman (Figure 3).2 The toads’ life cycle depends on the presence of karst topography, a formation of porous limestone bedrock that, among other things, causes water to drain very quickly through the stone, providing a small window of time for the toads who use the pools to breed. This habitat has been steadily disappearing for decades, especially in the highly developed northern part of the island. By the 1950s, the Puerto Rican crested toad was considered extirpated from the wild.

Figure 3: Puerto Rican crested toads mating in a tub at the Buffalo Zoo, November 2005. Buffalo Zoo herpetologist Penny Felski explains that the captive toads are conditioned for breeding by fasting, undergoing a brief cooling period, being fed and treated with an anti-fungal bath and, finally, being introduced to each other in tubs set up to simulate breeding ponds. Felski tells me: “Here, the male [on top] grasps the female in amplexus—an amphibian mating position—while waiting to fertilize the eggs that she will lay” (interview). Courtesy of John W. Kast.

In 1966, reports of toad sightings surfaced in northern Puerto Rico, “but no one knew how much stock to put in those stories.”3 In 1974, Professor Ernesto Estremera played some recordings of crested toads for his high school students, telling them that “these toads no longer exist in Puerto Rico.”4 A student from Quebradillas raised his hand and told Estremera that he had heard those calls before, on his father’s land.5 This property had “a cow on it, and a few horses, and a cattle trough that was constructed from concrete for the cows to have a water source. . . . And, lo and behold, that turned out to be the case.”6 Estremera was delighted; so too were numerous herpetologists, who descended on Quebradillas to conserve what were perhaps the last few members of this species in existence. Juan Rivero, then a herpetologist at the Mayaguez Zoo in Puerto Rico, took some specimens back to the zoo and when those bred, Mike Evans, a biology student working at the zoo, contacted his friend Rick Payne, the reptile curator at the Buffalo Zoo, to see if Buffalo wanted any of the offspring.7 They did, and this serendipitous chain of events is how the collaboration with North American zoos began.

Many people were upset over the transfer of the toads into captivity, and over their transfer away from the island in particular. “It was controversial,” says Bob Johnson, curator of reptiles and amphibians at the Toronto Zoo, which got involved shortly after Buffalo. Johnson later became the first coordinator of the toad’s Species Survival Plan (SSP)—the program established by the North American Association of Zoos and Aquariums (AZA) to facilitate captive breeding between accredited zoos.8 Initiated in 1984, the Puerto Rican Crested Toad SSP was the first amphibian captive breeding program in a zoo. The toad was designated as endangered by Puerto Rican law in 1984, as threatened by the U.S. federal Endangered Species Act in 1987, and as Critically Endangered on the IUCN Red List of Threatened Species in 2004.9

“Some people thought they shouldn’t have collected them from the wild,” Johnson reiterates. “But if this were the case they likely would have disappeared entirely,” as all water sources in northern Puerto Rico have been drained for human use.10 He further explains that human water management prevents the formation of natural pools that provide breeding sites for the toads—meaning that the toads’ already small populations, limited to habitats with karst formation, are curtailed even further. “We’re building ponds now,” Johnson continues. Initially, the architectural model for the ponds was “the cow model, of course. Because we knew it worked,” he says, referring to the cow troughs on the high school student’s land in Quebradillas that provided breeding ground for the toads.11 We figured that “if we build these ponds, [the toads] are going to find their way to them, so that’s what we’re doing.”

In addition to helping construct artificial ponds for the toads to breed in, zoos have been providing a steady supply of toadlets and tadpoles for reintroductions to Puerto Rico. The toadlets are flown in from North America and released during the hurricane season. “We do timed breeding in November, hoping there’s a hurricane,” Johnson tells me. “If there isn’t one, we have no water to put the toads in.”12 In such instances, the biologists involved in the recovery program have needed to come up with innovative strategies, such as trucking in water to fill the reproduction ponds.13

In early 2014, approximately 600 toads were managed in captivity among thirty-one zoos.14 According to Diane Barber of the Fort Worth Zoo, who replaced Johnson as the SSP program’s coordinator when he retired, “we currently only have fifteen institutions that participate in captive breeding efforts for reintroduction. Their toads are kept in permanent isolation rooms, separate from all other zoo animals, to reduce the risk of introducing novel pathogens to wild populations.”15 A manufactured seasonal change—whereby the temperatures in the room are dropped abruptly for four weeks, rainfalls are simulated by using sprinklers,16 and recorded breeding calls are played—re-creates the toad’s ideal mating conditions. “When everything works, a female can lay up to 4,000 eggs that typically hatch within 24 hours,” the Toronto Zoo website indicates.17

Alongside the genetically valuable toads, toads who are over-represented within the program’s breeding population are considered “surplus” and used by zoos as “exhibit toads.” The genetically valuable tadpoles hatched in North American zoos are released in Puerto Rico every year to sustain and rebuild the wild population (Figure 4). As I have mentioned in the introduction, between 1983 and 2014, 290,000 tadpoles were released into man-made ponds in Puerto Rico.18

Even so, one of the more difficult challenges of the program has been the acquisition of land for breeding sites. “We had a few release ponds in the north,” Johnson says, but “we didn’t have ‘protected areas’ in the north like we did in the south. The development in the north is tremendous. It’s all homes, and holiday homes, and hotels—so most of those cattle troughs were being destroyed. As a cattle pasture, [the land] was worth nothing—but as a hotel site it was worth a fortune.”19 In fact, the Toronto Zoo tried to buy a small tract of land with a pond that would have been a perfect release site for the toad, but the $18,000 price tag proved prohibitively expensive. Although he raised almost the entire sum, Johnson came up short by $5,000. “So we never did it,” he tells me. “We were so close, and this site had some endangered plants on it, and some lizards. It would’ve been a dream site. But it never happened.”20

Figure 4: A joint in situ–ex situ team collects weight, length, and DNA samples from each toad (seen here in plastic bags) and tests them for chytrid fungus before releasing them in northwestern Puerto Rico in November 2013. Earlier that day, the toads were flown into Puerto Rico from North American zoos. Courtesy of Carlos Pacheco, USFWS.

The toad’s story in the south has been no less dramatic. Guánica State Forest in southwest Puerto Rico is a dry forest that lies in a rain shadow—the side of a mountain that normally receives very little rainfall—and gets heavy rain only during hurricanes.21 In 1984, Hurricane Klaus caused a beachside parking lot in Tamarindo, near the state forest, to flood. Miguel Canals, the forest ranger at Guánica, arrived at the site that day. He recounts the day’s events in detail:

One day, on the 4th of July, 1984, I was driving this road that we’re driving on now at about 6 a.m., [estimating] damage to the forest because twenty inches of rain had [just] fallen in forty-eight hours. It was a mess. While I was driving right here, I reached an area where I could not pass. All this was serendipity. And I stopped . . . and suddenly I heard something: Akluklukluklukluklu, Akluklukluklukluklu. “What the hell is that sound?” I asked. So I started looking around, and I looked in the mangrove and I saw a little toad, and I looked at it and I said, “Well, that’s not a bufo, that’s not any toad I know!” . . . I got into the water and I captured one, and then I noticed the crest. I had never seen one in my life. But just like the crested toad, it had this crest here. . . . So, I called San Juan in the morning, 7:30 a.m., and I said: “Look, mira. This is Miguel. I found these toads. I am very sure it is a crested toad.” I remember when the guy I talked with started laughing and said to the herpetologist that was near him, “Mira! He is crazy! Miguel says that he has a crested toad at the beach, in the salt flat!” And I heard that and I said, “Mira! I no crazy! I no crazy! I’m sure that he is a crested toad!” They came that same night. And I took them driving at night and suddenly three crested toads were crossing the road, so we stopped—and then they went crazy. “Oh, I can’t believe it! Oh my God! Oh!”22

Meanwhile, Guánica’s mayor had sent workmen to drain the parking lot so that fishermen and tourists could visit the beach.23 Only at the last moment did Canals manage to stop the workers from doing so. “This area has been the crested toads’ for the past half million years,” Canals tells me. “The artificial thing is the parking lot.”24 More intervention was needed, however, for the toads’ breeding to be successful. To this end, a secondary breeding pond was built out of concrete in nearby Manglillo Grande and has been populated annually. Since 1992, seventeen zoos have released more than 144,653 tadpoles at Manglillo, one of six current release sites for the toads.25 Tamarindo remains the primary wild habitat of the Puerto Rican crested toad, and Canals insists that “his” wild population not be mixed with any captive ones.

Notes

1. Miguel Canals (forest ranger, Guánica State Park), interview by author, on-site, Guánica, PR, January 16, 2014.

2. WAZA, “Puerto Rican Crested Toad,” http://www.waza.org/en/zoo/choose-a-species/amphibians/frogs-and-toads/peltophryne-lemur.

3. Robert (Bob) Johnson (curator of amphibians and reptiles, Toronto Zoo), interview by author, telephone, July 24, 2013.

4. CBSG, “Population and Habitat Viability Analysis for the Puerto Rican Crested Toad,” 45, http://www.cbsg.org/sites/cbsg.org/files/documents/PRToad.FINAL_.pdf.

5. Johnson, interview.

6. Ibid.

7. Ibid.

8. Braverman, Zooland, 164–67.

9. Barber, e-mail communication; Ariadne Angulo, “Peltophryne Lemur (Puerto Rican Crested Toad),” The IUCN Red List of Threatened Species, Version 2013.2, http://www.iucnredlist.org/details/full/54345/0. A technical note: this book follows the common citation format for the species’ threat designation. Accordingly, I capitalized the threat designation when assigned by the IUCN Red List of Threatened Species (e.g., Endangered), but I did not capitalize the ESA designations (e.g., endangered), as the USFWS typically does not use capitalization in its materials.

10. Johnson, interview.

11. Ibid. According to Diane Barber, the ponds are now constructed differently. Barber, e-mail communication.

12. Johnson, interview.

13. Barber, e-mail communication.

14. Carlos Pacheco, “The Puerto Rican Crested Toad: Once Thought Extinct, Now Recovering,” USFWS, http://www.fws.gov/endangered/map/ESA_success_stories/PR/PR_story2/index.html; Barber, e-mail communication.

15. Barber, e-mail communication.

16. Ibid.

17. “Puerto Rican Crested Toad,” Toronto Zoo, http://www.torontozoo.com/AdoptAPond/pdfs/Puerto%20Rico%20crested%20toads.pdf.

18. Barber, e-mail communication.

19. Johnson, interview.

20. Ibid.

21. Ibid.

22. Canals, interview.

23. Johnson, interview.

24. Canals, interview.

25. Barber, e-mail communication. See also Lacy, “Re-Thinking Ex Situ vs. In Situ Species Conservation,” 27.