A habitat suitability model to assess population status and management implications for beaver in Wisconsin

Abstract

Beaver (Castor canadensis) act as ecosystem engineers shaping wetland ecology. Their potential to affect hydrology and habitat for numerous species makes beaver management crucial and often complex. To inform management strategies and evaluate management actions, it is important to understand the broad-scale distribution of the species and its habitat. We set out to develop a model that provides a metric of relative quality of beaver habitat and capacity for beaver across the varied ecosystems of Wisconsin, USA. Because beaver are tied to specific habitat characteristics (waterways and wetlands), habitat suitability models (HSMs) can be a powerful tool to describe the distribution of their habitat across the landscape. We applied an HSM framework to estimate the relative capacity of each natural waterway in Wisconsin to support beaver colonies. We found that beaver habitat quality varied widely across the state from areas of low-gradient streams with ample wetland vegetation in the north to areas where slope or lack of riparian vegetation limited capacity for beaver in the agricultural and unglaciated regions. We used this model to examine the potential impact of management actions in terms of the proportion of beaver habitat (weighted according to HSM scores) affected. This HSM model provides a tool to help wildlife managers understand beaver distributions, plan population management, and evaluate future management scenarios.