The Legacy Partnership: Discovering the Effects of Cheatgrass on Nesting Raptors

06 July 2010

burrowing_owl_couple_mouth_openEach spring raptors embark on the vital task of nesting.  This is a period of great vulnerability, and nesting raptors face many risks such as predation, human disturbance, and prey availability.  A recent HawkWatch International (HWI) technical report indicated that non-native, invasive cheatgrass could compound these risks for nesting raptors, especially Burrowing Owls, Ferruginous Hawks, and Golden Eagles.  Upon first sight, cheatgrass appears to provide an ideal nesting place for raptors, but in fact, research suggests that cheatgrass results in lower abundance of primary raptor prey like ground squirrels and black-tailed jackrabbits.  Burrowing Owls and Ferruginous Hawks, both Wildlife Species of Concern in Utah, are open-country species adapted to native grasslands, shrubsteppes, and deserts of western North America; as such, they may be particularly sensitive to alteration of these habitats by the exotic cheatgrass.

As a result of HWI’s study, the Department of Defense (DoD) Legacy Resource Management Program awarded funds to a partnership between HWI and prominent federal, state, and non-profit groups, to further research the negative impacts of cheatgrass in Utah’s Great Basin.  The Legacy Resource Management Program was created in 1990 by Congress to assist DoD in protecting and enhancing resources while supporting military readiness.

The research study, which begins in the Spring of 2010, will look at abundance of prey and the reproductive performance of Burrowing Owls, Ferruginous Hawks, and Golden Eagles in high cheatgrass areas.  Scientific and management tools including a central nesting database, standardized data collection protocols, and a management plan, will help land managers in the region and elsewhere better conserve nesting raptors.  HWI looks forward to working closely with DoD - Dugway Proving Ground, partnership facilitator, as well as DoD - Hill Air Force Base, Bureau of Land Management (BLM), Raptor Inventory Nest Survey (RINS), US Fish and Wildlife Service, Utah Department of Wildlife Resources, and a volunteer eagle observer.