Zoos Saving Species: Puerto Rican Crested Toad
Written By: Shannon Irmscher, Animal Curator
The Puerto Rican crested toad (PRCT) was once plentiful on Puerto Rico as well Virgin Gorda, a part of the Virgin Islands. Their numbers have dramatically declined, and they are now found in very fragmented populations, most notably in a small area of Guánica state forest on the southern coast of Puerto Rico. One major reason for this decline is loss of their habitat. The shallow, temporary ponds that occur during the rainy season and are necessary for PRCT breeding, have been drained to repurpose the land for agricultural and urban development. The cane toad is a similar but much larger species that is not native to Puerto Rico but has been introduced to the island. Because they are larger, cane toads can outcompete the Puerto Rican toads for food and breeding resources. In 1987, the US Fish and Wildlife Service classified crested toads as threatened, and in 2004 they were classified as critically endangered by the International Union for the Conservation of Nature. The small remaining wild population is very susceptible to disasters brought on by natural or human causes.
In 1984, the Association of Zoos and Aquariums (AZA) established a Species Survival Plan (SSP) for these toads, the first SSP for amphibians. This plan focuses on captive breeding to ensure a healthy population with genetic sustainability. Today nearly 20 AZA-accredited zoos participate in the breeding and reintroduction of this species. They recreate the toad’s natural breeding environment and sometimes use special hormones to aid in the reproduction process. If successful, the toads will lay hundreds of eggs in long strands. Within just one day, those eggs start to morph into tadpoles! Once they are a few days old, they are counted and prepared for overnight shipment to Puerto Rico. Upon arrival, they are housed in manmade ponds to monitor their development, after which they are released into a few different locations on the island. Each year, there are thousands of tadpoles sent from these zoos back to the wild to live.
Earlier this year, Mesker Park Zoo acquired 10 Puerto Rican crested toads. They are around three inches long, yellowish brown in color, and are named for the raised ridges above their eyes. They are on exhibit in the Discovery Center. Their natural habitat consists of a rocky terrain so you can probably find them hiding between two of the rock slabs in their exhibit next to the Panamanian golden frogs. These individuals have been retired from the breeding program and will now be exhibit animals that spread awareness for their species. Even though we will not be breeding this species here, offspring from the toads here at Mesker have been released into the wild!