Adjustments of the Northwestern muskrat (ondatra zibethicus spatulatus) to a Northern environment ...

• Main Author: Stevens, Ward Earl
• Format: Text
• Language: English
• Published: University of British Columbia 2012
• Subjects: Arctic; Mackenzie river
• Online Access: https://dx.doi.org/10.14288/1.0106456; https://doi.library.ubc.ca/10.14288/1.0106456

The northwestern muskrat (Ondatra zibethicus spatulatus) is nowhere more abundant than in the delta of the Mackenzie River in northern Canada. An investigation was undertaken to assess the adjustments resident animals have made in order to inhabit a region more than one hundred miles inside the Arctic Circle. The rigours of the physical environment demand that these animals live in burrows rather than in lodges of vegetation, as in more southern areas. During summer the breeding pairs may occupy shallow temporary habitat which is not suitable for tenure during winter. These summer sites must be vacated before ice seals the lakes and prevents escape from a rapidly deteriorating environment. That all muskrats do not desert this temporary summer habitat was indicated by the fact that only half as many marked animals from such sites were encountered subsequently. It may be assumed that a depressed survival was the rule in such locations. Only deeper lakes with adequate submerged food plants constituted ...