A comparison of the dynamics of pairs of adjacent moose (Alces alces) populations, one lightly harvested by controlled hunts and the other heavily harvested by open hunts, was conducted in 3 areas in southwestern Quebec. Computer simulations were used to evaluate effects of different hunting regimes on populations, and to generate management predictions. The model assumed that predation was the major mortality factor in the absence of hunting, and that natural mortality was density dependent. The model gave acceptable predictions. Results revealed that density was inversely related to hunting pressure. Field data suggested that unbalanced sex ratios diminished productivity; when this relationship was included in simulations, it appeared to predict observed differences. To optimize moose harvest in southwestern Quebec, we recommend retaining at least 40% males among adults, increasing calf cropping, and limiting hunting to the level of maximum sustained yield. J. WILDL. MANAGE. 45(3):598-611 Computer models for simulating responses of wildlife populations to harvest schemes are being used with increasing frequency. Workers seldom lack ingenuity for simulating population mechanisms; a major limitation, however, arises in applying existing data to calibrate and test these mechanisms. Without a basic understanding of population responses, quantitative predictions having the accuracy required by managers cannot be made. The study reported here, involving 2 levels of hunting pressure on moose, appears to demonstrate that simulated relationships based on data can provide a reasonable basis for management predictions. Moose management in North America has been strongly influenced by the concepts of net and gross productivity (Pimlott 1959), but these do not account for variations in density or nonhunting mortality as functions of hunting impact (Caughley 1974). Caughley (1976) preented a model for ungulates that was based on optimum yield, as was the more general model of Clark (1976); we have applied this approach to moose. In Quebec, the number of moose hunters increased from 43,000 to 98,000 between 1964 and 1977, while the legal take remained relatively stable at 8,000 moose, resulting in declining hunter success (Bouchard and Gauthier 1978). It was essential to determine whether the decline was due to a declining moose population, an inability of new hunters to find suitable hunting sites, or increasing wariness of moose. We designed a study to document effects of different hunting pressures on moose populations, and constructed models to incorporate field data for predicting an optimum-yield management strategy. We thank D. St.-Hilaire, who was in charge of the aerial surveys for most of the project, and J. Boivin, L. Breton, G. Michaud, D. Pare, R. Pariseau, and M. Poulin, who participated in the surveys. We appreciate the skill of pilots B. BenI Present address: Department of Zoology, Clemson University, Clemson, SC 29631. 598 J. Wildl. Manage. 45(3):1981 This content downloaded from 157.55.39.163 on Wed, 21 Sep 2016 05:39:53 UTC All use subject to http://about.jstor.org/terms MOOSE HARVEST IN QUEBEC* Crete et al. 599 bridge, P. Langlois, J.-G. Lejeune, F. Lemieux, Z. Lemieux, C. Richard, and B. Samson and mechanics P. Saint-George and T. To. The computer center of the University of Minnesota provided computer time for simulations.