American Bird Conservancy has petitioned the U.S. Fish & Wildlife Service to list the Oregon Vesper Sparrow as a threatened or endangered species under the Endangered Species Act (ESA). In a letter sent to Sally Jewell, Secretary of the Interior, ABC describes this subspecies of the Vesper Sparrow as highly imperiled and threatened with extinction throughout its range. The petition makes the case that the species warrants listing because it lacks adequate protection under existing regulatory mechanisms. Without ESA listing, the sparrows’ future looks grim. The current estimated population of the Oregon Vesper Sparrow is fewer than 3,000 birds, and Breeding Bird Survey data indicates a statistically significant population decline of more than five percent every year over the last 45 years.
This migratory species has a restricted breeding range that historically included southwestern British Columbia, western Washington and Oregon, and northwestern California. Now, breeding populations have disappeared from British Columbia and California, along with numerous local breeding populations throughout the range.
The species overwinters in California west of the Sierra Nevada Mountains and south of San Francisco Bay, and historically it ranged into northwestern Baja California, Mexico. But wintering populations in Baja and southern parts of California have now disappeared.
“We are deeply concerned about the future of this bird,” said Bob Altman, ABC’s Pacific Northwest Conservation Officer. “With so few birds remaining, many in small and isolated populations, the Oregon Vesper Sparrow (Pooecetes gramineus affinins) needs the immediate protection and conservation focus made possible through ESA listing."
The bird primarily feeds on insects during the summer, along with spiders and other small invertebrates, and feeds heavily on seeds in the winter.
Sources: Chattanoogan, 22 December 2016