'A really big deal': CPW discovers wild boreal toad tadpoles at reintroduction site near Pitkin

John Livingston
Southwest Region Public Information Officer
970-759-9590 / [email protected]
@CPW_SW

GUNNISON, Colo. – Daniel Cammack made the familiar trek up to a wetland at 11,500 feet of elevation for the seventh consecutive year in an effort to boost Colorado’s population of state endangered boreal toads.

When he arrived at his destination high above the town of Pitkin, Cammack and his team of Colorado Parks and Wildlife native aquatic species biologists made a potentially game-changing discovery for the future of boreal toad conservation in the state: wild tadpoles at a translocation site.

“This is a really special day. We have been reintroducing toads at this site since 2018, and this is the first time that we have observed wild reproduction occurring,” Cammack said while standing in front of a pool of a few dozen wild tadpoles. “It’s a really big deal.”

The site near Pitkin was previously devoid of the toads. But in 2013, CPW identified it as a good potential habitat for translocation for the species. In 2017, CPW stocked the first 600 boreal toads at the site to be used as sentinels for chytrid fungus, a widespread pathogen implicated in the decline of this species. 

Since then, CPW has stocked an estimated 20,000 tadpoles at the site. The vast majority originated as eggs collected from wild populations in remote backcountry areas and were transported to be raised at CPW’s Native Aquatic Species Restoration Facility in Alamosa. An additional 570 tadpoles raised at the Denver Zoo Conservation Alliance were stocked at the site in 2022.

Female boreal toads are not reproductively mature until about age 6, and the discovery of wild tadpoles gives Cammack confidence the site will continue to produce into the future.

“For years, we have been watching multiple age classes thrive at this site, so we had high hopes this was going to become a self-sustaining breeding population and a successful translocation,” he said. “This is the first year we’ve seen breeding occurring in this wetland, and it is evidence of that success.

“This day is a culmination of a lot of dedicated people’s efforts, including multiple biologists, technicians and hatchery personnel. Everyone who has been involved in this project has poured their heart and soul into it. That's what it takes to get here.”

If the tadpoles morph into toadlets later this summer and recruit into adult boreal toads, the translocation site will become only the second in Colorado where natural breeding has occurred. The first is near Cameron Pass in northern Colorado.

Boreal toads are listed as a state endangered species in Colorado. Once common in montane habitats between 7,000-12,000 feet in the Southern Rocky Mountains, the boreal toad has experienced dramatic population declines over the past two decades. The decline appears to be related to habitat loss and primarily infection by the chytrid fungus, which can infect most of the world’s 7,000 amphibian species, and is linked to major population declines and extinctions globally.

CPW and partners from the Boreal Toad Recovery Team have devoted significant resources in the past 20 years toward researching the cause of boreal toad declines in the state and exploring ways to recover the species. Partners have included the states of New Mexico, Utah and Wyoming, federal agencies such as the U.S. Fish and Wildlife Service, U.S. Forest Service, Bureau of Land Management and National Parks Service, the Denver Zoo Conservation Alliance and universities that have conducted critical research.

Specifically, CPW researchers focus on developing methodologies for reintroducing toads in historically occupied habitats, detecting chytrid fungus in the wild, marking and identifying individual toads and improving breeding success at the Native Aquatic Species Restoration Facility, which plays a critical role in the state’s efforts to restore populations of boreal toads.

“The boreal toad is a truly unique and resilient amphibian,” said Cammack, a Native Aquatic Species biologist for CPW in the Southwest Region. “We are up at 11,500 feet, at timberline practically. They gut out big winters covered by multiple feet of snow and experience only three to four months of warm growing season.

“They are an integral part of the landscape, as far as I’m concerned. They were ubiquitous once in Colorado in this habitat. With chytrid fungus now being the primary cause of decline, we don’t have that many populations of boreal toad remaining. For us to get something else going here is really important.”

Cammack has scouted much of southwest Colorado in search of wild boreal toad populations or suitable translocation sites. He called the discovery of the new tadpoles a monumental day in his career.

“These are the native species that were historically abundant and so common that it would have been hard to imagine this major decline,” he said. “As someone who grew up in Colorado and loves wildlife, I wish I could jump in a time machine and experience these ecosystems before they faced these major threats. No doubt, critters like boreal toads were here in force.

“Unfortunately, they have since declined so far that they represent only a shadow of the past. It’s a mandatory crusade, in my opinion, to conserve the fragments that remain and keep these creatures represented on the landscape. Like all native creatures, they have an inherent right to exist. Our story and identity as Coloradans are more intact when these populations thrive.”