Beaver Reintroduction in the Absaroka-Beartooth Wilderness
Feb 25, 2016
Beaver Reintroduction in the Absaroka-Beartooth Wilderness
Absaroka-Beartooth Wilderness
Greater Yellowstone Ecosystem
(1,475 sq. miles)
Release Areas
Eagle CreekHellroaring Creek
Buffalo Creek Slough Creek Stillwater River
Project Origin
Abundant habitat devoid of beaver
(Early 1980’s)
Wilderness Reintroduction Requirements
•Positive affect
•Unable to recolonize
•Sufficient habitat
•Extirpation by humans
•Historically present – currently absent
Preparatory Documents
•Minimum tool – Wilderness character•NEPA – Effects and public input•BA & BE – Protected species
An Ecosystem Engineer
Riparian habitat enhancement
Colonization potential
Sufficient Habitat
20 miles: 1st-3rd order streams
Human role
Beaver abundant until 1950’s
Beaver absent in 1985- but evidence of past occupancy
Cause of demise:
•Trapping
•Tuleremia
•Willow decline
West Fork Cabin – symbol of a trapping era
A source for beaver– damage complaint
System for delivery
Relocation constraints :- Family groups- Early fall release
130 relocated – 40 at primary release sites
Trapping curtailed
What can we learn?
Management actions as investigations
1986-2010 Annual structure inventories
DamsLodgesBank LodgesCaches
Inventory Example: Frenchy’s Meadow
Quantification of Physical Variables
• Stream sinuosity
• Stream width and depth
• Sandbar distance
• Willow canopy
• Distance to confluence
Results 1986-2010:
• Carrying capacity reached – year 2000
• Colonies = 1.33/ km
• Willow and standing water >15%
Carrying Capacity Model:
Colony success correlated with: - Greater stream sinuosity and depth- Less distance to secondary channel- Fewer gravel bars
Colony success not correlated with: - Willow canopy