Genetic Assessment of Blanchard’s Cricket Frog for Recovery to Pelee Island, Ontario.
Blanchard’s cricket frog (Acris crepitans blanchardi) is a small (1.6-3.8 cm), warty, non-climbing member of the tree frog family. These aquatic frogs prefer open permanent water such as mud flats, stream banks,
and marshes. Originally, they ranged from Texas through the central states (Nebraska, Iowa, Illinois, Ohio, Wisconsin, Michigan), and into southwestern Ontario on Pelee Island and Point Pelee.
The Canadian population of Blanchard’s cricket frog is listed as endangered by both the federal and provincial government, and the species has not been seen on Pelee Island since 1987. Populations throughout much of its northern U.S. range are also in decline, and is also classified as endangered in Wisconsin. Natural flooding, predation, dredging of drainage ditches, fertilizers and pesticides, and fragmentation of wetlands are factors thought to have contributed to this frogs disappearance from Canada.
The Canadian Blanchard’s Cricket Frog Recovery Plan is supported by several agencies, with a breeding colony maintained by the Toronto Zoo. The goal is to restore the species to its original Canadian distribution. This component of the recovery plan will profile the genetic composition of historic and extant populations. This will be used to identify the best population from which to draw source animals for the reintroduction of Blanchard’s cricket frog into Canada. The genetic composition of the original Pelee Island population will be determined from historic specimens located at the Royal Ontario Museum and the Canadian Museum of Nature.
Profiling recent specimens from across the frogs’ current range will establish whether different “forms”
of the species exist in southern versus northern areas. If so, it may not be appropriate to move southern-adapted animals to southwestern Ontario. However, if no genetic distinctiveness is found,
it may be ideal to draw source animals from southern populations rather than disturb the already declining ones of the northern United States.
The ideal recovery program will establish several connected populations of Blanchard’s cricket frog on Pelee Island. This will allow gene flow to maintain genetic diversity, but will also provide a colonisation source in the event of localised extinctions. established, genetic testing will continue to assess the levels of genetic variation and connectivity among populations, and the potential risk of extinction of
the newly introduced animals.
For more information, please contact Kaela Beauclerc, Paul Wilson, or Brad White at Trent University, Peterborough, Ontario.
Frog Range Map