The North American river otter (Lontra canadensis) is considered a top predator in many freshwater systems in Michigan and throughout the continent of North America. As a semi-aquatic piscivore, river otters serve a critical role in linking aquatic and terrestrial ecosystems yet the current understanding of river otter distribution is limited to relatively small spatial scales. A landscape analysis was used in this study to assess river otter distribution in Michigan; this approach allowed for broad spatial assessment at the state scale and furthermore assessed the importance of both aquatic and terrestrial habitat components. I designed and evaluated an approach to identify landscape features related to river otter distribution in Michigan at two spatial resolutions with specific attention given to the relationship between river otter occurrence via trapping records and prey availability. A multiple linear regression model identified surface water quantity and wetland configuration, along with percent crop cover, to be effective parameters in predicting river otter harvest at the county scale (adjusted R2 = 0.67). At the local catchment scale, human population density, number of road crossings, percent crop cover, and percent canopy cover explained 62% of a predictive, maximum entropy model of species occupancy (AUC = 0.733). This analysis helps to identify the river otter's large scale habitat needs, highlighting the importance of connectivity between aquatic and terrestrial systems for effective, landscape-based management of fish and wildlife resources.
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