Overharvest of Fox Squirrels from Two Woodlots in Western Ohio

Abstract

Harvests of fox squirrels (Sciurus niger) from 54 acres (21.8 hectares) of oak-hickory woodlots located on a public shooting area in western Ohio were analyzed to determine the effects of hunting on the squirrel population over a 7-year period, 1965-71. Yields averaged 1.00 squirrel per acre (2.5 squirrels per hectare) the first 4 years, 1965-68, but declined significantly to an average of 0.60 squirrel per acre (1.5 squirrels per hectare) the last 3 years, 1969-71. Squirrel harvests were significantly correlated with the preseason squirrel density but were not significantly correlated with hunting pressure each year. High sustained hunting pressure and the ease of hunter access to all portions of two woodlots combined to allow hunters to shoot a high proportion of the resident squirrel population. Hunters recovered an average of 47.1 percent of the marked adult females, 59.1 percent of the adult males, 33.3 percent of the subadult females, and 58.1 percent of the subadult males in the first hunting season after tagging. The average annual mortality for marked adults and subadults combined was 91.8 percent; 75.2 percent of this mortality was a result of hunting. Preseason squirrel densities in the total harvest were significantly correlated with the kill of subadults, the recovery rate of adults, and the total kill of adults for the previous year. During the last 3 years, 1969-71, the adult squirrel population was reduced by hunting to a level that could not produce enough young to bring preseason densities up to 1965-68 levels. There was a substantial immigration of subadults into the study area during the hunting season in the last 4 years. Small wood lots on public hunting areas may be difficult to manage for fox squirrels without some restraint on hunting opportunity. Management of these woodlots should be based on a concept of sustained yield rather than on hunter success, because hunter demand far exceeds the supply of squirrels. J. WILDL. MANAGE. 38(1):67-80 Fox squirrels inhabiting public hunting areas are frequently subject to annual hunting pressures several times higher than squirrels on privately owned forests (Peterle and Fouch 1959). Each year as hunting opportunities decline on private lands, more squirrel hunters seek their recreation on public hunting areas. Game managers should be concerned with the effects of this continuing heavy hunting pressure, particularly as the resulting squirrel harvests affect population densities and the maintenance of population equilibrium from year to year. The present paper reports on 7 years of harvest data (1965-71) for 54 acres (21.8 hectares) of woodlots located on a public hunting area in western Ohio. Our aim was to study the effects of hunting on a fox squirrel population exposed to relatively long (88-98 days) hunting seasons that began in early September before many litters born in midto late summer were weaned. In extensive forests there seems little doubt that both gray (S. carolinensis) and fox squirrels are usually underharvested (Allen 1952, Uhlig 1955). However, Allen (1943:335), Allen (1952:28), and Baumgartner (1943:193) reported overshooting of fox squirrels inhabiting small woodlots in Michigan, Indiana, and Ohio, respectively. These authors believed that squirrel populations in woodlots were sustained by an immigration of squirrels from adjacent, more lightly hunted, populations. Where woodlots were small and widely separated, population recovery was slow after years of high kill (Baumgartner 1943:193). 1A contribution of Federal Aid in Wildlife Restoration Projects, Ohio W-105-R and Illinois W66-R. J. Wildl. Manage. 38(1):1974 67 This content downloaded from 207.46.13.126 on Sat, 24 Sep 2016 04:49:41 UTC All use subject to http://about.jstor.org/terms 68 OVERHARVEST OF OHIO SQUIRRELS * Nixon et al. Peterle and Fouch (1959) published the only long-term study of the effects of hunting on fox squirrels in woodlots. They found that short (22 days) October hunting seasons did not materially change the fox squirrel population. We acknowledge personnel of the Ohio Division of Wildlife who assisted with livetrapping and operation of the checking station. H. C. Schultz and W. R. Edwards, Illinois Natural History Survey, reviewed the manuscript.