DENVER — On Wednesday, Nov. 10, a team of conservation and amphibian experts from Denver Zoo traveled to the Native Aquatic Species Restoration Facility in Alamosa, Colo. to pick up 95 boreal toads that will act as an additional breeding population for their species.

The toads were brought back to a specially-designed facility at the Zoo where they were put into brumation—a natural state of inactivity during winter months—before attempting to breed them in the spring of 2022.

Officials from the Zoo and Colorado Parks and Wildlife hope to raise and release as many as 20,000 tadpoles into the Colorado wilderness next summer, boosting an endangered species for Colorado and New Mexico.

“Boreal toads are in a lot of trouble, but their numbers are still relatively strong even though their population is in decline,” said Stefan Ekernas, Rocky Mountain/Great Plains program director at Denver Zoo. “Colorado Parks and Wildlife has done a tremendous amount of work on the conservation of boreal toads for almost 30 years, and we’re excited to join in the effort to help the species make a meaningful recovery while there’s still time.”

Once common in montane habitats between 7,000-12,000 feet in the Southern Rocky Mountains, the boreal toad has had dramatic population declines over the past 20 years. The decline seems to be related to habitat loss and infection by the chytrid fungus, which can infect most of the world’s 7-thousand amphibian species, and has been linked to major population declines and global extinctions of various species.

“We have had success in the past producing boreal toad eggs and tadpoles at NASRF, but it is challenging, and with the increasing need for more animals, we need to step up breeding and reintroduction efforts,” said Harry Crockett, Native Species Aquatic Species coordinator for CPW. “This is a great opportunity for boreal toad conservation and collaboration with a strong conservation partner in Denver Zoo.”

Denver Zoo has been active in amphibian conservation for over 15 years. In 2018, the Zoo became the first zoo in the Northern Hemisphere to successfully breed critically endangered Lake Titicaca frogs and has since provided more than 250 healthy frogs to zoos and aquariums in the U.S. and Europe.

In 2019, the Zoo used a hormone treatment to breed and produce more than 600 boreal toads, which were released in southwestern Utah.

In 2021, the Zoo successful bred critically endangered Panamanian golden frogs as part of the Association of Zoos and Aquarium’s Species Survival Plan.

Officials from the Zoo and CPW estimate that it will take many years to bring the species back to a level where it is secure in the Southern Rocky Mountains, and anticipate this to be a multi-year program. The Zoo will launch a community science project where volunteers monitor survival of released toadlets and evaluate potential release sites around the state.