Modeling emigration of wolves from a wilderness area into adjacent agricultural regions

Abstract

We developed and applied a simple population model to examine the relation between abundance of wolves in a wilderness area and the numbers that emigrate into adjacent agricultural areas and that may need to be removed on an annual basis. The model was applied using Minnesota wolf (Canis lupus) data. The gray wolf is emigrating from northern wilderness areas in the State of Minnesota (USA) into adjacent agricultural and urban areas to the south, and the costs of both wolf control and compensation to farmers for lost livestock is increasing as the number of wolves increases. Emigration reduces the number of wolves on a refuge to about 85% of the carrying capacity, and the number of wolves that emigrate into the agricultural area is 6% of the number on the refuge. With control on the refuge the number of wolves killed is about 10% of the carrying capacity or 24% of the wolves on the refuge, but control on the refuge results in less emigration. A conservative control strategy, in which abundance on the refuge is closer to the carrying capacity and emigration increases slightly, can increase the number of wolves on the refuge with a small increase in emigration.