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DENVER (KDVR) – In mid-July, a group of wildlife experts, along with the help of some wildlife-loving volunteers, reintroduced roughly 600 boreal toad tadpoles to Colorado’s high country.

This is an effort to help the species numbers move toward a self-sustaining level.

According to Colorado Parks and Wildlife, there are an estimated 800 boreal toads still living in the wild today. That alarmingly low figure is why the Denver Zoo and Colorado Parks and Wildlife have come together to help improve their numbers through the forming of the Boreal Toad Conservation Team.

FOX31 spoke with Jake Kubie with the Denver Zoo to get the breakdown of what the team aims to achieve, what’s been done so far and what led up to this need for human intervention.

Contributing factors to the boreal toad’s decline


For the past two decades, the species of toad native to the southern Rocky Mountain region has been decreasing at an alarming rate.

According to a study conducted in 2003 by the U.S. Geological Survey, the annual survival rates for male boreal toads trended as follows:

  • From 1991 to 1994: The annual survival rate was 78%
  • In 1995: The annual survival rate had dropped to 45%
  • From 1998 to 1999: The annual survival rate dropped to heavily to 3%

As this figure dropped, so too did the number of egg masses, which according to Amphibian Planet are long strings of eggs laid out along plants or on the bottoms of shallow water in ponds.

This decrease has been attributed to chytrid fungus or, Batrachochytrium dendrobatidis, which is also referred to as “Bd.”

According to Kubie, if a toad comes in contact with the fungus known as Bd, it can contract a disease that carries a “very high mortality rate.” The increase in Bd’s presence in regions where the boreal toad population has been negatively impacted has been, at least partially, attributed to climate change.

The efforts of the Boreal Toad Conservation Team

Release of Boreal toad tadpoles in Gunnison National Forest
Release of Boreal toad tadpoles in Gunnison National Forest
(Credit: Colorado Parks and Wildlife)

According to the project’s information page, the two major aims of the Boreal Toad Conservation Team are:

Breeding and release

  • This includes preventing the species’ numbers from reaching zero in the wild.
  • Improving the boreal toad’s immunity to Bd.

Community science

  • This means observing boreal toads in Colorado to learn where best to release tadpoles during future reintroduction efforts. This part of the group’s efforts requires help from volunteer community scientists, which is where you come in.

If interested, you can apply to join Team Toad.

Kubie told FOX31 a breeding program was launched to counter this concerning trend in 2019.

In March of this year, as part of this program, Denver Zoo officials went down to the Colorado Parks and Wildlife’s Native Aquatic Species Restoration Facility in Alamosa to retrieve adult boreal toads for the purpose of breeding.

Once they were brought back to the Denver facility, wildlife experts with the zoo were able to help the toads successfully reproduce, which in total spawned 600 tadpoles.

Kubie said the boreal toad’s preferred habitat is at an elevation between 7,000 and 12,000 feet. In July, to comply with this preference, the team took those freshly spawned specimens to Gunnison County and released them in some of the area’s waterways.

Officials made sure that the area that the tadpoles were introduced into was not impacted by the, Bd, fungus that has been causing the species so much trouble.

What’s next for the boreal toad?

The term used to describe the boreal toad’s hibernation state is brumation. During extended periods of colder weather, lizards, amphibians and reptiles slow down and become sluggish in nature, which leads to them burrowing in rock chambers located near streams, beaver dams or another small mammal’s burrow.

The National Park Service said that this is due primarily due to hibernacula, which is a process that occurs near running water that keeps the temperatures above freezing.

Now that brumation season has arrived and has sent boreal toads into their seasonal sleep of sorts, so have the efforts of the conservation team.

But, if you want to stay updated on when their conservation efforts will resume in the spring of 2023, sign up for Team Toad and spread the word about these endangered toads native to Colorado that could use some helping human hands on their journey back to an un-endangered status.