Management of the North American Beaver (Castor Canadensis) on the South-Savo Game Management District, Finland (1983–1997)

Abstract

Two pairs of North American beavers (Castor canadensis) from the USA were introduced in Sääminki in southeastern South-Savo in 1937. The present population is the offspring of these two pairs. Currently, the beaver population is rapidly increasing and causing considerable damage to forest and agricultural land. Therefore there is a need to manage the beaver population at a lower, but sustainable level through hunting. However, it is impossible to develop a beaver management plan without quantitative data about beaver from this area. The South-Savo Game Management District has estimated the population density of beavers using annual questionnaires to hunters from 1983–1997. Furthermore, the occurrence and amount of damage caused by beavers was determined in 1995 and 1997. Hunting clubs manage 68% of the total area of South-Savo which encompasses about 2.17 million ha. Twenty-five percent of this area is water. The beaver population has increased from 1100 to 3000 individuals from 1983-97, and the respective number of lodges has increased from 400 to 1280. The beaver density is highest in the southeastern part of the study area, but the range is also expanding to the west. The occurrence of damage had a patchy distribution and was highest in the eastern part of the study area where the beaver density was highest. The total area of extensively flooded land caused by damming activity was 475 ha in 1995 and 321 ha in 1997 while overly wet areas increased from 581 ha to 598 ha, respectively. During the study period, 14% to 27% of the beaver population was harvested annually. Hunting is only allowed in areas where