Influence of Introduced Mink on Newfoundland Muskrat

• Main Author: Soper, Leah R.
• Format: Thesis
• Language: English
• Published: University of Wisconsin-Stevens Point, College of Natural Resources 2020
• Subjects: Canada; Newfoundland
• Online Access: http://digital.library.wisc.edu/1793/80626

The influence of introduced mink (Mustela vison) on an island race of muskrat (Ondatra zibethicus obscurus) was studied in insular Newfoundland using harvest statistics, field surveys, and stomach analysis. Fur harvest records show an increase in the mink harvest from 932 in 1958-59 to 2,770 in 1991-92 and a decrease in the muskrat harvest from 11,146 in 1958-59 to 897 in 1991-92. Presence of the introduced mink on a race of muskrat unadapted to mink, combined with marginal habitat conditions, have limited muskrat population growth in Newfoundland. Best muskrat populations were associated with dense stands of water horsetail (Eguisetum fluviatile), which was used to build houses which seemed to protect muskrats from mink. Wildlife Habitat Canada (WHC), the Newfoundland and Labrador Trappers Association (NLTA), and the Newfoundland and Labrador Wildlife Division (NLWD), Department of Culture, Recreation, and Youth