Archive: Detroit Zoological Society Jumps In To Save Critically Endangered Toad

Nearly 8,000 zoo-born Puerto Rican crested tadpoles released into the wild

June 6, 2019

ROYAL OAK, Mich., 

Thousands of critically endangered Puerto Rican crested toad tadpoles left Detroit on June 5 for Puerto Rico, to be released in the El Tallonal biological reserve as part of a federal program to restore wild populations of the amphibian. The 7,809 tadpoles join the nearly 84,000 Detroit Zoo-born tadpoles released in Puerto Rico over the past decade. Fifteen of the tadpoles remain at the Zoo’s National Amphibian Conservation Center for future breeding.

“These tadpoles represent hope for this critically endangered species,” said Dr. Ruth Marcec-Greaves, director of the National Amphibian Conservation Center. “Many amphibian species, such as the Puerto Rican crested toad, are declining and would not survive in the wild without captive breeding programs. This release will significantly bolster the number of these toads in their natural environment.”

Detroit Zoological Society (DZS) amphibian staff spent more than six hours counting and packing the tadpoles into padded and insulated shipping boxes for their journey. Heavy-duty fish-shipping bags were doubled up and filled with oxygen to keep the tadpoles healthy and safe en route. “It was all hands on deck as the amphibian staff counted and packed thousands of tiny tadpoles,” Marcec-Greaves said.

Approximately 24 hours later, the tadpoles were released in their new home – a pond located in a well-protected forest in Puerto Rico. The population of Puerto Rican crested toads in Puerto Rico is monitored to determine if released animals are surviving and breeding, and the captive breeding program has shown to successfully boost the wild population.

The Puerto Rican crested toad is among half of the world’s known 8,030 amphibian species threatened with extinction due to habitat loss, climate change, pollution, infectious diseases and other factors.

The Puerto Rican crested toad (Peltophryne lemur) has greenish-brown pebbled skin and marbled golden eyes. It grows 3-4 inches long and has the ability to nearly flatten its body to fit into tiny crevices. These toads can be challenging to spot in their habitat at the Detroit Zoo, but visitors can often see their large eyes and pointy, hooked noses peering out from under their naturalistic limestone structures.

The National Amphibian Conservation Center opened at the Detroit Zoo in 2000 and remains the only major facility dedicated entirely to conserving and exhibiting amphibians. Dubbed “Disneyland for toads” by The Wall Street Journal, it houses a spectacular diversity of frogs, toads, salamanders, newts and caecilians. The award-winning, state-of-the-art facility is world renowned for amphibian conservation, care, exhibition and research.