TORONTO, ON, Thursday, January 23, 2020: In December 2019, two Toronto Zoo Keepers, Rick Vos and Laura Huculak, travelled to Puerto Rico with eight other representatives from the Association of Zoos & Aquariums (AZA) institutions to participate in a week’s worth of field work related to three separate conservation projects on the island, in particular the Puerto Rican crested toad (PRCT). The PRCT is listed as a Critically Endangered species by the International Union for Conservation of Nature and is found only in Puerto Rico. In collaboration with the U.S. Fish and Wildlife Service (USFWS) and AZA Species Survival Plan (SSP), tadpoles hatched at the Toronto Zoo are released in Puerto Rico each year for the purposes of sustaining and rebuilding the wild population.

The group travelled to El Tallonal, an established reintroduction site, where two artificial ponds have been constructed for the reintroduction of PRCT hatched in various AZA institutions. PRCT tadpoles were witnessed in the ponds. These tadpoles were determined to be produced from previously released tadpoles that are now wild toads and the group explored the habitat in search of adult toads. Successional forest growth taking over, following canopy loss from the hurricane two years ago, made it difficult to see the toads that are well hidden by the extra vegetation.

From there, the next leg of the research trip began at a new base on the southwest corner of the island, Combate Beach. It was an exciting moment in the trip as the group was scheduled to pick up a shipment of 193 juvenile PRCT that were produced using in vitro fertilization techniques. This was the first time PRCT were produced through in vitro techniques developed at the University of Mississippi and supported by AZA, the USFWS and the Department of Natural and Environmental Resources. These toads were part of an important research study to track their movement and dispersal after they were released at Los Conventos, a reintroduction site in Guayanilla. This is a rare release of metamorphosed toads, as PRCT are typically released as tadpoles. Some toads had small tracking devices affixed to them, while others were marked with a fluorescent powder.

The information gathered from the marked PRCT helped us to understand a more about dispersal patterns for the toadlets after they are released. It also served as a test to determine the effectiveness of the two different methods used for marking and tracking the toads. We found several of the released toads and both methods of marking and tracking proved effective.

“After working with the Zoo’s breeding population of PRCT for the past five years and sending thousands of tadpoles back to Puerto Rico for release, it was great to visit the island to see the results of our efforts,” says Rick Vos, Lead Keeper Amphibians & Reptiles, Toronto Zoo. “Meeting many of the collaborators in this ongoing recovery effort and witnessing the in situ components of the project was one of the highlights of my thirty-year zoo career. I’m very grateful to have had the opportunity to participate in this pioneering endangered species recovery program.”

The important field work conducted for PRCT was also accompanied by the group joining a PRCT working group meeting where various partners were able to present on the work they have been doing to support PRCT recovery at various locations on the island. Following the meeting, we visited the Tamarindo site where the original ephemeral ponds that supported the last breeding population of toads on the island were discovered decades ago. These ponds were essentially large puddles that filled up after the wet season. The toads would use them to breed in. At that time, the ponds were not protected, they were in the middle of a parking lot used by beach goers. Since then, the site has been closed off to vehicle traffic and a boardwalk has been built to protect the habitat and toads from foot traffic. Additional artificial ponds have also been constructed in the area to help with recovery efforts.

“One of my personal highlights from the field work in Puerto Rico was seeing the toads in their natural habitat, and knowing they could be descendants from the Toronto Zoo,” says Laura Huculak, Wildlife Care Keeper, Toronto Zoo. “Meeting the people in Puerto Rico committed to the recovery program was inspiring. Seeing people working together across the continent with the common goal of saving this important endangered species is one of the many reasons I became a Zoo Keeper.”

The SSP for the PRCT was developed, in part, to reintroduce the species back into the wild. The Toronto Zoo has been an active participant in the breeding program for over 30 years. We are proud to announce that, with the addition of this year's tadpoles, the Toronto Zoo has contributed a total of 157,286 PRCT that have been released back into the wild. The work accomplished with PRCT has shown us that it takes a long term, sustained commitment to a program like this to achieve success when recovering a species from the brink of extinction. The Toronto Zoo hopes to continue its effort to save this unique and endangered toad in the years to come.

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