Wednesday, May 20, 2015

New Study of Oregon Vesper Sparrow Confirms Small Population

(Washington, DC, May 15, 2015) Concerns about the long term fate of the Oregon Vesper Sparrow (Pooecetes gramineus affinis) have escalated following a recently completed range-wide inventory for the bird led by American Bird Conservancy (ABC), one of the nation's leading bird conservation organizations.

"The results confirm our initial concerns of a small and severely declining population based on Breeding Bird Survey data, and suggests a population certainly not larger and likely smaller than our earlier estimate of approximately 2,100 birds," said Bob Altman, who led the study and is ABC's Northern Pacific Conservation Officer.

The Oregon Vesper Sparrow, which is a larger sparrow with gray and brown feathering, is a subspecies of the more common Vesper Sparrow. It was once a common bird that inhabited grassland and savannah areas west of the Cascade Mountains in southwestern British Columbia, western Washington and Oregon, and a small portion of northwestern California.

Funding from the U.S. Fish and Wildlife Service multi-state grant program supported the extensive survey effort (both roadside and off-road on accessible lands) based on previous detections and potential habitat throughout nearly all the bird's range. Sparrows were detected at only 13 percent of the approximately 700 roadside point count stations. This was true even though researchers targeted places where the birds were recently detected, adjacent potential habitat, and additional potential habitat identified through extensive imagery interpretation and driving reconnaissance.

The greatest concern is populations in the Puget Lowlands and Willamette Valley ecoregions where there are less than 500 birds in each ecoregion. Meanwhile, the stronghold appears to be light to moderately grazed rolling hills and pasturelands in the Umpqua Valley of southwestern Oregon, where large ranches are the norm.

"The next step for ABC will be to complete a conservation status assessment to recommend conservation actions. It may even be necessary to petition that this bird receive federal protection under the Endangered Species Act," said Altman. The conservation assessment will be completed within the next year.

A species is added to the endangered species list when it is determined to be endangered or threatened because of any of the following factors:

the present or threatened destruction, modification, or curtailment of its habitat or range
overutilization for commercial, recreational, scientific, or educational purposes
disease or predation
the inadequacy of existing regulatory mechanisms
other natural or manmade factors affecting its survival

Among the conservation benefits authorized for threatened and endangered plants and animals are: protection from being jeopardized by federal activities; restrictions on take and trade; a requirement that the U.S. Fish and Wildlife Service develop and implement recovery plans for listed species under U.S. jurisdiction; authorization to seek land purchases or exchanges for important habitat; and federal aid to state and commonwealth conservation departments with cooperative endangered species agreements. Listing also lends greater recognition to a species' precarious status, encouraging conservation efforts by other agencies, independent organizations and concerned individuals.

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American Bird Conservancy is the Western Hemisphere's bird conservation specialist—the only organization with a single and steadfast commitment to achieving conservation results for native birds and their habitats throughout the Americas. With a focus on efficiency and working in partnership, we take on the toughest problems facing birds today, innovating and building on sound science to halt extinctions, protect habitats, eliminate threats, and build capacity for bird conservation.