MIGRATION DISTANCES OF MOOSE POPULATIONS IN RELATION TO RIVER DRAINAGE LENGTH

Abstract

To aid moose management in Sweden we want to be able to predict the yearly distribution of migratory moose populations based on winter inventory data since summer inventory data are lacking. As a first step in developing this method, we compared migration distances of moose in 11 populations to the upstream-lengths of river drainage is that winter concentration areas were located along. The winter concentration areas were in both coastal and mountainous-inland regions in central and northern Sweden. Mean and maximum migration distances of moose in the different winter concentration areas were found to be correlated with the length of respective river drainage, and moose generally migrated upstream from winter to summer areas. River drainage length and direction of flow appear to be major factors related to the maximum distances and direction that moose migrate from winter concentration areas. By noting the location of a winter concentration area along a river drainage, it may be possible to estimate the migration distances of the population and thus the length of the population's yearly distribution. This method will be further developed to more accurately estimate the area, in addition to the length, of the yearly distributions of migratory moose populations.