Gonzalez Voyer, A., Smith, K.G. & Festa-Bianchet, M. 2003: Dynamics of hunted and unhunted mountain goat Oreamnos americanus populations. - Wildl. Biol. 9: 213-218.
Native populations of mountain goats Oreamnos americanus are sensitive to harvest. To assess the potential effects of limited hunting on population dynamics, we analysed long-term data obtained from aerial counts of 12 native mountain goat herds in Alberta, Canada, during 1973-2001. Seven herds were hunted until 1987 and five were not hunted. Despite a decrease in the number of permits issued, mountain goat numbers declined in most hunted herds between 1980 and 1983. Hunting was closed in 1987. Only three of seven herds increased after hunting was closed. Unhunted herds also showed substantial among-herd differences in population trends. Our results suggest that factors other than sport hunting contributed to the population decline. Future harvests should target adult males, but the adult sex ratio of one intensively studied population was heavily biased in favour of females. A herd of 100 goats may only sustain the harvest of 1-2 adult males per year.
Key words: aerial surveys, Alberta, censusing, hunting, mountain goat, population dynamics, sex ratio
Alejandro Gonzalez Voyer* & Marco Festa-Bianchet, Groupe de Recherche en écologie, nutrition et énergétique, Département de biologie, Université de Sherbrooke, Sherbrooke, PQ J1K 2R1, Canada - e-mail addresses: aglez@miranda.ecologia.unam.mx (Alejandro Gonzalez Voyer); marco.festa-bianchet@usherbrooke.ca (Marco Festa-Bianchet)
Kirby G. Smith, Fish and Wildlife Division, 111-54 Street, Edson, AB T7E 1T2, Canada - e-mail: kirby.smith@gov.ab.ca
*Present address: Laboratorio de Conducta Animal, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, A.P. 70-275, 04510, Mexico D.F.
Corresponding author: Alejandro Gonzalez Voyer
Received 25 January 2001, accepted 30 September 2002
Associate Editor: Harry V. Reynolds