Individuality in captive and field measures of behavior and space use in wild muskrat (Ondatra zibethicus)

Abstract

The role of individual behavioral tendencies in wild populations remains largely unstudied, especially in mammals, despite its potential ecological importance. We examined whether individual variation in muskrat (Ondatra zibethicus) behavior in a captive novel environment correlates with other measures of behavior and habitat use. We compared the novel environment assay behavior with handling docility and trap habitat for all animals. We radio-collared subadults to look for correlation between assay behavior, summer space use, trappability and likelihood of autumn dispersal. In the novel environment test, we found many muskrat did not exit the shelter during the test. Muskrat that entered the arena showed activity and boldness/emotionality axes similar to behaviors identified in other taxa in similar tests. Participation in entering the arena appears to be related to boldness rather than activity. Both participation and boldness were lower in subadults and higher in males. Neither activity nor boldness of participants in the novel arena was correlated to handling docility, suggesting that such measures would not be interchangeable for evaluating muskrat behavioral tendencies. None of these behaviors related to fine-scale habitat use as reflected by the capture site. In subadults they did not relate to field measures of home range composition, trappability or autumn dispersal, and there is only a suggestion of a positive correlation between captive activity and home range size, although small sample size limits the power of these subadult analyses. Muskrat vary in their behavioral responses in captivity, but there is no strong indication that this variation reflects differences in space use in the wild.