The toad that’s uniquely Canadian

Canadian researchers have made a remarkable wildlife discovery that could transform conservation efforts, uncovering new genetic evidence about a familiar amphibian with significant implications for biodiversity and species protection. Western toad. Credit: Jayna Bergman, University of Ottawa. A new study published in the journal Diversity and Distributions analyses the genetics of the Western toad, found across North America and the provinces of Alberta and British Columbia. The team from the University of Ottawa discovered that the genetically distinct and exclusively Canadian population of the Western toad ( Anaxyrus boreas ) highlights the country's unique biodiversity and the implications this holds for conservation. What makes these toad populations special? The lead author of the study, Jayna Bergman, and her team travelled across Alberta and British Columbia, collecting samples from toads and tadpoles to conduct ancestry-type testing, which compared the toads' DNA to see how closely related they were. They discovered that the ‘Calling’ and ‘Non-Calling’ Western toad populations are genetically distinct. Calling toads have vocal sacs and make mating calls, and non-calling toads do not have sacs and do not make mating calls. The new evidence shows that the differences are not just behavioural – they're also genetic. DNA changes slowly over time, meaning that populations that have been separate for long periods can accumulate small genetic differences. By measuring these differences, researchers can determine which animals belong to the same genetic group and which belong to distinct groups. “Our findings of a genetically distinct group entirely contained to a Canadian province is very unusual. These genetic results suggest we should be doing more to protect this species, especially the Alberta population of the Western Toad because of its unique complement of the species’ total genetic diversity,” said Bergman, a PhD student from the Faculty of Science and Professor Julie Lee-Yaw’s lab. Related article Frogs and toads are disappearing but here's how you can make them at home by making a simple pond Western toads are crucial for their ecosystems and have been designated as a Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and are listed under the Species at Risk Act. Toads with vocal sacs live east of the Rocky Mountains, and those without live west of the Rocky Mountains, with habitat potentially playing a role in these differences. “This ‘advertisement call’ provides a notable difference in breeding strategies and may be the only example of such an extreme difference in calls within what are considered the same species,” explained Assistant Professor Lee-Yaw from the Department of Biology. In Canada, wildlife protection decisions are dependent on identifying unique or distinct populations. In this case, the differences in mountains and climate associated with them seem to have helped keep the two groups of toads separate. The team also discovered a third genetic group of western toads in the southern Canadian Rocky Mountains. Many species in Canada were studied decades ago using limited genetic tools, but modern techniques have helped identify previously unrecognised populations. Future research Bergman says the next phase of the research should compare western toads across their entire range to understand how the different groups arose and whether they could possibly mate with each other, which is essential for testing whether they could become a different species. News reference Bergman, J. C., Enciso‐Romero, J., Pauly, G. B., Gamlen‐Greene, R., Todd, M., & Lee‐Yaw, J. A.. (2026). Pronounced Genetic Structure Associated With Differences in a Reproductive Trait and Climatic Barriers in Canadian Populations of the Western Toad ( Anaxyrus boreas ). .