DISPERSAL OF JUVENILE FISHERS IN MAINE

We studied natal dispersal of fishers (Martes pennanti) in a harvested population in southcentral Maine during 1984-90 because of concern ov er the high level of harvest and a lack of information about fisher di spersal. Probability that an individual would disperse by the end of i ts first year was 73 and 100% for males and females, respectively (n = 21 M, 12 F). However, 32% of males and no females dispersed before th e age of 9 months. Mean distance between natal and adult home ranges d id not differ (t = 0.16, P = 0.88) between males (n = 8, xBAR = 10.8 k m, range = 4.1-19.5) and females (n = 5, xBAR = 11.2 km, range = 5.0-1 8.9). Dispersal, in combination with intrasexual territoriality of adu lts, may limit fisher density and competition for food. Dispersal of n early all juveniles allowed them to quickly replace adults removed by fur trapping. However, the short distances moved by dispersing fishers may limit their ability to recolonize areas from which fishers have b een extirpated, and may reduce interchange among isolated populations.