Each fall, the 1854 Treaty Authority coordinates a small mammal survey. The purpose of the survey is to monitor trends in annual abundance of small animals like mice, voles, and shrews that are important in the diets of predators like fisher, pine marten, and owls. A number of cooperators ranging from other management agencies to schools and private individuals participate in collecting information on trends in small mammal abundance across the northern portion of Minnesota. The survey consists of 3 transects with 10 stations each. At each station two mouse traps baited with peanut butter are set and checked for two consecutive days. Captured animals are identified and counted.
An abundance index is then created by calculating the average catch rates for each species. This abundance index for small mammals can then be compared to abundance information for furbearers like fisher and pine marten. There appears to be fairly good correlation between years of abundant small mammals in the woods and good numbers of juvenile fisher and pine marten in the fall trapping harvest, highlighting the importance of a good prey base to these furbearing species.