Ninety-five endangered boreal toads are in brumation — a natural state of inactivity similar to hibernation — at the Denver Zoo after arriving from a facility in Alamosa last month.
While the toads aren’t doing much at the moment, the Denver Zoo has teamed up with Colorado Parks and Wildlife (CPW) to breed the amphibians in the spring. They want to release as many as 20,000 tadpoles back into the wild next summer, according to a release from CPW. The toads came from the Native Aquatic Species Restoration Facility run by CPW.
Denver Zoo spokesperson Jake Kubié said the zoo wants to replicate its success in breeding and releasing these toads in Utah. The zoo used hormone treatment to breed and create more than 600 boreal toads in 2019, which were then released in southwestern Utah.
The zoo has a track record of breeding rare frogs and toads
It successfully bred critically endangered Panamanian golden frogs this year. In 2018, it became the first zoo in the Northern Hemisphere to successfully breed critically endangered Lake Titicaca frogs.
Kubié said the boreal toads are in a special refrigerator at the zoo. The toads used to be found in habitats between 7,000 to 12,000 feet in elevation in the Southern Rocky Mountains, according to CPW’s release. But the amphibians have experienced a dramatic population decline due to habitat loss and infection by the chytrid fungus, which is common among amphibians species. Both agencies estimate it will take years to bring the toads back to their pre-endangered levels.
The boreal toad is listed as endangered in Colorado and New Mexico.