Harvest Status, Reproduction and Mortality in a Population of American Martens in Québec, Canada

Abstract

Effects of trapping on a previously unexploited (since 1895) population of American martens (Martes americana) were investigated (1984–1994) in the Laurentides Wildlife Reserve, Quebec. We used trapline-specific data on total harvest and trapping effort, and the age and sex distribution of 8, 801 carcasses to evaluate a commonly applied age- and sex-ratio index for evaluating harvest sustainability. Percent of males in the harvest was linearly related to trapping success. However, juvenile: adult female and juvenile: ovulating female ratios were not significantly related to harvest or trapping success. A sex ratio in favor of males (1.3 to 1.6) male: female was positively associated with trapping success (1.3 to 1.5 captures/100TN) during the last 6 years of the study. Ovulation rate for 1-yr-old females was 44% during 1984–1985, and increased to 76% in 1990, a unique finding for American marten. Mean ovulation rate (4.11 corpora lutea/ovulating female) was exceptionally high for American martens and did not vary significantly among years. The number of ovulations per adult (>2 yrs) female was 3.21; this is among the highest values reported for marten in North America. Annual mortality rate for all ages classes (35%) was similar to the rate calculated for the >5-yr-old cohort. However, mortality rates for martens in the 0–3-yr cohort were 61% (1984–86) and 66% (1990–91). Although sex ratio seemed to be a reliable index of harvest intensity, other commonly used harvest indices (e.g., juveniles: adult females; juveniles: ovulating females) were not significantly related with trapping success. Use of traditional harvest indices for managing marten populations was not supported by our results.