CALF HARVEST AND REPRODUCTIVE RATE OF REINDEER IN FINLAND

Despite a 2-fold increase in density and consequent habitat deteriorat ion, reproductive rates of reindeer (Rangifer tarandus tarandus) in Fi nland have increased even in herds without supplemental feeding. Winte r foods are limited, and reindeer dig for food beneath snow the entire winter; calves commonly share feeding sites with their mothers. Using 28 years of data on calves per female for 56 herds, we found that cal f removal led to compensatory changes in reproductive rates in 12 nort hern herds and the strength of the relationship between' harvest rates of calves in years t; and calf to female ratio in year t + 1, was gre ater the longer the period of use of snow-covered foods. Calf harvesti ng appeared to relieve density-dependent suppression of reproductive r ate, even at high reindeer densities. Thus, calf harvesting apparently can increase the carrying capacity of the habitat, which concomitantl y may lead to an increased rate of exploitation of that habitat.