Conservation of Fish Species At Risk in Canada: Populations At the Edge of Their Range

In North America, the native ranges of many species reach northward into southern Canada.  These species at the edge of their range often have limited distributions and are considered rare in Canada.  Several aquatic species whose range extends into southern Canada, and whose main population is found further south, are listed by the Committee on the Status of Endangered Wildlife in Canada and subsequently, have been afforded protection under the federal Species at Risk Act.  There is an ongoing debate as to whether such species deserve protection merely based on political boundaries, if they are more abundant elsewhere in their range.  To determine which ecological traits predict a species to be listed as at risk in Canada, all fish species were assigned values for various ecological and life history traits, including being at the northern edge of their range in Canada, based on published literature.  A classification and regression tree (CART) analysis was conducted in R, using the statistical package TREE.  Being at the northern edge of its range in Canada was a significant predictor of at risk status.