Reintroduction of Beaver into Appropriate Habitat on BLM Land

Alec Porterfield1*, Koby Kercher1*, Matthew Bair1*, Milo Pohlen1*

1Colorado Mesa University, Grand Junction, Colorado, United States

The North American Beaver (Castor canadensis) plays a very important role in stabilizing and improving the health of many aquatic and riparian habitats within the United States. Beavers do this by providing invulnerable ecosystem services, such as maintaining the health and resilience of hydrologic functions, biological functions, and geological functions. For various reasons such as post European expansion and habitat loss, beaver populations have declined drastically, negatively affecting aquatic and riparian ecosystems.

This project was conducted to determine if there are suitable locations for beaver reintroduction on BLM land within the Grand Junction field office boundaries. The project used the BRAT model on ArcGIS Pro while comparing the data to real-world data gathered in the field, which was used to determine the model's accuracy.

The main attribute of the BRAT model that was focused on for this project was “Existing Dam Building Capacity (dams/km)”. This focus considers other BRAT model attributes to calculate the capacity of dams per kilometer. Reaches were labeled either blue, green, orange, yellow, or red. Three reaches were selected with varying degrees of capacity. Reach 1 (Dominguez/ Escalante Campground Reach) had the greatest capacity of 5-15 dams/km (green reach), reach 2 (Highway 141 Reach) had a lower capacity of 1-5 dams/km (yellow reach), and reach 3 (Little Park Road Reach) had the lowest capacity of 0 dams/km (red reach). Ground assessments were conducted at each of the reaches with a scorecard sheet being used to calculate a score based on suitable vs unsuitable habitat characteristics (score of –78 to 100).  This was done by observing the slope, vegetation type, vegetation cover, etc. Reach 1 had the greatest score of 79, reach 2 had a lower score of 38, and reach 3 had the lowest score of –13. Each reach received a score that correlated with the BRAT Model existing dam building capacity.

The Dominguez–Escalante reach is the most suitable site for beaver reintroduction with the Highway 141 reach being a good alternative. The Little Park Road reach is unsuitable for beaver reintroduction and should not be considered as a viable site.

The project confirms that the BRAT model is accurate and can also be utilized by the Bureau of Land Management to locate additional or alternative sites for beaver reintroduction.  It is recommended that ground assessment still occur even though the BRAT model is accurate. The next steps would be to contact Colorado Parks and Wildlife and reintroduce the beavers to areas where they are most likely to survive and prepare a starting point for them to expand on.