The potential harvest of woodchucks [Ressource potentielle en marmottes américaines].

Résumé

Several years of research provide data for an analysis of the potential harvest of woodchucks. Data for birth and mortality rates, age composition, and numbers were obtained from 1957-1960 at Chambersburg, Pennsylvania. Information about 135 birth rates and age composition was obtained from two areas. In one, many woodchuck were removed in an unsuccessful attempt to reduce the population in the other, only a small number were taken. From these data, a set of four hypothetical cases is postulated at different birth and mortality rates. The harvest can be compared under four circumstances: (A) harvest of adults without compensatory effects on natural mortality, (B) compensation but no harvest of young, (C) compensation and harvest of young, or (D) compensation for both adults and young. Under realistic conditions, the maximum harvest was obtained from a population of l00 woodchucks with a birth rate of 1.6, a probability of survival of adults of 0.57, and of the 135 young of 0.27, if harvest replaced all of natural mortality.