Consequences of harvesting on age structure, sex ratio and population dynamics of red deer Cervus elaphus in central Norway

We explore some of the consequences of harvest on population growth rate, a ge and sex structure in a Norwegian population of red deer Cervus elaphus, using age-structured demographic models. Survival rates were estimated from individuals marked and monitored annually during 1977-1995, and informatio n about reproduction patterns were obtained from hunting material in the sa me region. The population had an actual doubling time of 14 years, correspo nding to a multiplication rate of 1.051. Harvesting led to a reduction of a bout 10% of the potential multiplication rate that equalled 1.166. Includin g stochasticity had only a small effect on the population multiplication ra te. Due to a high hunting pressure, males had less than a 10% chance of rea ching 4.5 years of age and the male-biased harvest strongly biased the sex ratio. Assuming that when the number of females per male increases above a given threshold some females would not manage to mate, we investigated at w hich level male harvesting could be maintained without having demographic c onsequences on the population growth rate. We concluded that the hunting pr essure on males could probably be increased further but indirect consequenc es of a strongly biased sex ratio (e.g. on population genetic structure) re main to be studied. Variation in the multiplication rate mainly resulted fr om the variation in winter calf survival. In its present form the harvestin g regime reduces the growth rate and biases the sex and age structure, but does not seem to threaten the population's viability and productivity.