Thousands of tiny tadpole travelers left Cleveland Metroparks Zoo Monday for a 1,800-mile journey to Puerto Rico, part of the Zoo’s contribution to the Puerto Rican crested toad Species Survival Plan, managed by the Association of Zoos & Aquariums (AZA).

This amphibian species is critically endangered, and the Zoo, along with the AZA and partner institutions both in Puerto Rico and here in the U.S., have been working together to breed the toads for release into the wild. The Zoo sent tadpoles to Puerto Rico in 2010, but the current clutch of approximately 4,500 specimens is a much larger group.

“The Puerto Rican crested toad Species Survival Plan has been very successful,” said Associate Curator of Animals Lynn Koscielny. “Field researchers in Puerto Rico have observed toads with transponders that were released into the wild returning to the protected ponds to reproduce.”

Once the Zoo’s tadpoles reach U.S. Fish and Wildlife – Caribbean Refuge officials in San Juan, they will be transported to one of three possible release sites on the southern coast of the island.

In order to successfully breed crested toads in a zoo environment, animal keepers need to mimic the conditions under which they would naturally breed in the wild. This involves cooling the toads down to 66 degrees and then placing them in a rain chamber tank that simulates the rainy season in the toads’ native Puerto Rico. A sound recording of the male crested toad’s mating call adds to the simulated environment.

The Puerto Rican crested toad is the only toad native to the island. Its numbers are threatened by habitat loss and competition from non-native introduced species such as the cane toad.

Currently, the Zoo has 10 adult Puerto Rican crested toads on exhibit in The RainForest.

Northeast Ohio’s most-visited year-round attraction, Cleveland Metroparks Zoo is open 10 a.m. to 5 p.m. daily. From November 1 through March 31, 2013, admission is discounted to $8.25 per person, $5.25 for kids ages 2 to 11 and is free for children younger than 2 and Zoo members. Parking is free. Located at 3900 Wildlife Way, the Zoo is easily accessible from Interstates 71, 90 and 480.

For more information, visit clemetzoo.com or call (216) 661-6500.