Deschutes County Wildlife Inventory Update

Later this summer, staff will coordinate with the Board of County Commissioners to share the public input and discuss incorporating the inventories into the Comprehensive Plan and zoning codes. If directed, staff will establish a robust public process with work sessions and public hearings before the Deschutes County Planning Commission and Board of County Commissioners to receive public testimony.

Lastly, additional community conversations relating to updating other wildlife inventories are anticipated as part of the Comprehensive Plan Update. The Community Development Department anticipates initiating a Comprehensive Plan Update (2040) in Fall 2021. The current Comp Plan covers the 20-year period from 2010 to 2030. While only 10 years old, demographic changes warrant revisiting the Comp Plan to ensure it accurately reflects existing conditions and trends, community values, and emerging opportunities.

Mule Deer (Odocoileus hemionus) Winter Range Habitat

The mule deer winter range habitat inventory was selected by the TAC for update primarily because it no longer reflects usage patterns indicated by data collected by ODFW biologists, and this habitat commonly is a source of conflict with proposed developments in the County.

The proposed inventory is based on these data sources:

• The biological mule deer winter range provides a general outline of mule deer winter range east of the crest of the Cascades in Oregon. ODFW considers the winter range to be that area normally occupied by deer from December through April.

• Aerial and ground survey observations of deer group sizes collected by ODFW biologists during each winter from 2015 through 2020 (unpublished)

• Mule deer resource selection function (RSF) model raster for probability of use in winter based on the “south central study” ( Coe et al. 2018 )

• Deer density polygons from two years of collar data for an area that was left out of the “south central study” (unpublished)

The newly selected blue areas represent significant winter range based on the raw data inputs described above and therefore these areas were identified for protection by the members of the IWG representing ODFW.

• The Current WA Zone for mule deer winter range covers approximately 315,847 acres.
• Blue polygons of new area cover an additional 188,132 acres.
• So, altogether the new winter range covers approximately 503,979 acres, a 60 percent increase.

The current inventory, illustrated by blue spheres with darker blue outlines, includes 5 bald eagle and 20 golden eagle nest locations, each buffered by a ¼-mile-radius sensitive habitat area.

The new inventory is based on these data sources:

• Oregon Eagle Foundation
• United States Forest Service Natural Resource Information System (NRIS) for terrestrial wildlife data
• Bureau of Land Management local records

• The new inventory buffers all known nest sites within each eagle territory and includes nests on all land ownerships within the County.
• Golden eagle nests are now buffered by a 2-mile-radius sensitive habitat area because they are thought to be more sensitive to disturbance.
• Bald eagle nests remain buffered by a ¼-mile-radius sensitive habitat area.
• The current inventory protects 2,297 acres of sensitive bird habitat associated with 25 nest locations (603 acres for bald eagles and 1,694 acres for golden eagles)
• The new inventory includes 116 bald eagle and 103 golden eagle nest locations.
• The updated nest locations and the larger radius of protected habitat associated with golden eagles results in 344,778 acres of sensitive bird habitat in the County.
• The larger number of nests and greater land base included in the new inventory do not necessarily correspond to increased eagle success or upward population trends. Survey methods have improved and survey efforts have greatly increased over the past several decades, resulting in the record of several alternative nest sites per territory (e.g. the 103 golden eagle nest sites represent 41 territories).

Current Deschutes County Wildlife Area (WA) Combining Zone for elk habitat (which focuses on winter range) covers approximately 51,717 acres.

The proposed inventory is based on these data sources:

• The biological elk winter range  (ODFW 2012)  which provides a general outline of elk winter range east of the crest of the Cascades in Oregon.

• Winter observation data collected by ODFW biologists from 2015 through 2020 (unpublished)

• ODFW biologists’ professional knowledge of winter range habitat use patterns by local elk herds