Amphibian Profile

Boreal Toad

It's Only a Northern Toad: The Dilemna of the Boreal Toad
by Justin Higgins

The boreal toad (Bufo boreas boreas) is currently considered to be a subspecies of the western toad (Bufo boreas). The western toad occurs throughout the western United States and Canada, while the boreal toad specifically can be found as far north as Alaska, down to the New Mexico and through various parts of Washington, Oregon, California, Idaho, Montana, Wyoming, Nevada, Utah and Colorado. Of particular interest is the endangered Southern Rocky Mountain population of boreal toad, which can be found in parts of Wyoming and New Mexico, but primarily in the mountains of Colorado.

The boreal toad has adapted to higher elevations, and is typically found at elevations ranging between 7,000 to 12,000 feet. In Colorado, it is the only toad found in alpine regions. Boreal toads have a few characteristics that set them apart from many other toads. They lack a cranial crest (the raised ridges between the eyes common on many toad species). They also have a light colored stripe running down the length of their back. Boreal toads have fairly warty skin, and their skin colors can vary from gray to green to brown. One way to distinguish the boreal toad from the main western toad species is by looking at its belly, which typically has a significant amount of dark blotches.

Finally, unlike many other species of toads, the boreal toad uses only a soft chirping sound, rather than a loud mating call. Generally, the boreal toad will only be found in areas that are good breeding grounds, such as lakes, marshes and ponds in spruce-fir forests and alpine meadows.

Current Status:

While the boreal toad used to be quite abundant, it has been suffering severe population declines since the 1970's. The Southern Rocky Mountain population has been most notably affected. Recently, a type of fungus known as chytrid fungus has been discovered in some local boreal toad populations. This fungus can be deadly and has been linked to a decline in amphibian populations in other parts of the world. Further research will help to determine how much this fungus might play a role in worldwide amphibian population declines.

The boreal toad had been a candidate for protection under the Endangered Species Act, but in September 2005, the US Fish & Wildlife Service announced that it was dropping it from the list. Their reasoning for this was that the boreal toad is only a subspecies of the western toad, and until it can be shown otherwise, they don't consider it to warrant special protection.

This decision has caused a lot of concern, but there is at least the possibility of a silver lining that could help the boreal toad and other amphibians in the long run. Since the boreal toad is no longer listed, it is now easier for biologists to study them without getting special permits. It's possible that it will be easier for scientists to study the boreal toad, both to understand its genetics and the fungus that could be killing it. The end result could be a way to help the boreal toad population become resistant to the fungus, and further genetic research may even help determine that the boreal toad is in fact a distinct species. If the boreal toad could be shown to be a distinct species from the western toad, it could win back protection under the Endangered Species Act.

So, although things are looking grim for the boreal toad right now, scientists may ultimately be able to understand more about them and how to help them and other amphibians.