Monitoring American Marten on the East-side of the North Cascades of Washington

Abstract

We used track plates to monitor American Marten (Martes americana) over 2 field seasons in 2003 and 2004 to test the efficacy of applying this technique to Late-Successional Reserves on the east side of the North Cascades. We stratified our sample area into wet and dry late-successional forest habitats in order to account for differences in habitat structure, disturbance regimes, and forest management strategies. We detected no Marten during either year in the dry-forest habitats. In the wet-forest habitats, detection rates were 0.29 in 2003 and 0.73 in 2004. The latency to detection in the wet-forest habitats was 5.5 d (s = 3.1) in 2003 and 5.6 d (s = 3.8) in 2004. The corrected probability of detection at a survey unit in the wet-forest habitat was 0.26 in 2003 and 0.42 in 2004. We then used the variability from our 2 sample years to estimate sample size requirements for different levels of power to detect changes in our abundance indices. Our study indicates that conservation efforts for the American Marten should be focused on the wet-forest habitats. This information should be useful to managers in designing a long-term monitoring program for American Marten.