Re-introduction of Puerto Rican crested toads to historic range in Puerto Rico

Summary

The Puerto Rican crested toad (Peltophryne lemur), critically endangered with its northern populations already extirpated, survives in the wild only in Guanica National Forest, where a single breeding pond has held between 500 and 2,000 adults over 25 years, leaving it vulnerable to a single catastrophic event. A coalition of 21 zoos and aquariums across the US, Canada, UK, and Puerto Rico, coordinated with the US Fish and Wildlife Service, Puerto Rico's Department of Natural and Ecological Resources, and other partners under a joint recovery plan and Species Survival Plan, aimed to establish six new self-sustaining metapopulations, three each in the historically occupied north and south. Only tadpoles, capped at a founder group of 20 per collection, were taken from the wild to maintain captive genetic stock, and a blanket annual permit let health-screened tadpoles be returned to Puerto Rico and released within six days of hatching into GIS-selected ponds outside the range of the surviving wild population. Monitoring relied on frog call loggers and graduate research, since tracking toads through subterranean limestone habitat and marking tadpoles both proved technically difficult. By the time of reporting, juvenile recruitment was confirmed at one southern release site, with the other two still under two years old, and toads released as tadpoles had themselves bred successfully over two subsequent seasons. The project rated itself Partially Successful, citing confirmed recruitment and breeding at the lead site and growing local ownership of the program, while long-term population persistence across all six planned metapopulations remains undocumented.