This toad exists only in Canada—and scientists have finally discovered why

Photo: Jayna Bergman/University of Ottawa

Scientists have identified something that may be even more uniquely Canadian than the beaver or moose: a genetically distinct western toad population found only in Canada. The discovery, made by researchers from the University of Ottawa, points to a rare and previously unrecognized group of toads living in the Canadian Rockies and raises fresh questions about conservation, biodiversity, and how much wildlife still remains to be fully understood. The study was published in Diversity and Distributions.

A toad found only in Canada

Western toads, or Anaxyrus boreas, are found across a wide stretch of North America, from Alaska to Mexico.But this new research shows that not all western toads are the same. A team led by University of Ottawa PhD student Jayna Bergman discovered a genetically distinct population that is entirely contained within a Canadian province, something she described as “very unusual.”That discovery matters because a population found only in one country can be especially important for conservation. If that group is lost, it cannot be replaced from elsewhere. Bergman said the genetic findings suggest that more should be done to protect the species, particularly the Alberta population, because it represents a unique part of the species’ overall genetic diversity.

How the researchers studied them

To reach their conclusion, Bergman and her team traveled through ponds, wetlands, and lakes across British Columbia and Alberta. They collected genetic samples from both toads and tadpoles and compared their DNA to see how closely the animals were related.The result was more surprising than expected. The researchers already knew that western toads in Canada generally fall into two groups: “calling” toads and “non-calling” toads. But the new genetic analysis showed that these groups are not just different in behaviour.They are genetically distinct as well.That means the difference is not only about how they sound or behave during breeding. It is written into their DNA. Over time, when populations remain separated, their genes begin to diverge. The longer that separation continues, the more likely it is that they will develop into clearly distinct groups.

Photo: Jayna Bergman/University of Ottawa

Calling and non-calling toads

One of the most interesting parts of the study involves the western toad’s mating call. According to assistant biology professor Julie Lee-Yaw, toads east of the Canadian Rockies have vocal sacs and produce an “advertisement call” during breeding, while toads west of the Rockies and in the southern part of the species’ range do not.That difference is unusual in itself. Lee-Yaw noted that this may be one of the most extreme differences in calls among animals that are still considered the same species. In other words, two populations can look similar on the surface but behave very differently when it comes to breeding.The mountains appear to be involved in maintaining the populations apart. Differences in climate and geographic barriers may have prevented gene flow between the populations, allowing the populations to stay apart long enough for genetic differences to build up.

A third group in the Rockies

The research team also uncovered a second major surprise: a previously undescribed third genetic group of western toads living in the southern Canadian Rocky Mountains. This group was found in southwestern Alberta and southeastern British Columbia, and the researchers believe it may extend south into Montana.This discovery is important because it suggests that the species is more complex than previously thought.For years, wildlife studies relied on older tools that could miss subtle genetic differences. Modern genomic methods are now revealing hidden diversity within species that were once assumed to be well understood.Bergman said the next step is to compare western toads across their full range to better understand how these groups evolved and whether they can still successfully mate with each other. That question matters because if the groups are becoming reproductively isolated, they could eventually be considered separate species.

Why this matters for conservation

Western toads already have conservation concern status in Canada. They are listed as a species of special concern by the Committee on the Status of Endangered Wildlife in Canada and are also protected under the Species at Risk Act. The new findings add another layer of urgency.If Canada holds a genetically unique population of western toad, then protecting that population becomes even more important. Wildlife protection decisions often depend on whether a population is genetically distinct, behaviourally unique, or separated by barriers that prevent mixing with other groups. This study suggests that the Alberta toads meet several of those criteria.For conservation planners, that can influence how habitats are managed, how future surveys are designed, and where resources should be directed.It also shows why local populations matter. Even within a species that spans an entire continent, one region may hold an irreplaceable piece of the genetic puzzle.

More than just another toad

At first glance, this may sound like a niche discovery about a small amphibian. But it is actually a reminder of how much biodiversity can hide in plain sight. A species that seems common and widespread can still contain rare, isolated, and genetically distinct populations that deserve special attention.The western toad’s case is also a good example of how science keeps changing what we think we know. What once looked like a single species with a few behavioural differences now appears to include deeper genetic divisions and at least one entirely unique Canadian group.That is why this discovery stands out. It is not just about a toad. It is about a piece of Canada’s natural heritage that may exist nowhere else on Earth.