The small population size of Oregon Vesper Sparrow is well-documented, but the reasons remain speculative. As with most migratory birds, declines may be caused by habitat factors on their breeding or wintering grounds, or migration stopover areas. This makes underlying causes more difficult to pinpoint, but potential factors include: loss and degradation of habitat due to development, fire suppression, exotic species, and/or agriculture. Oregon Vesper Sparrows may also be declining due to factors that generally affect small population sizes. Small populations lack genetic diversity and are less able to rebound after environmentally harsh years, breeding seasons with low productivity, disease, and natural disasters such as fires, floods, and drought. To begin to disentangle these potential causes of population decline, a group of collaborators are contributing to a range-wide study to assess limiting factors and inform conservation action. The three-year study will assess productivity, survivorship, dispersal/recruitment, and habitat in order to identify where within the Oregon Vesper Sparrow’s annual life cycle conservation actions are needed. Klamath Bird Observatory’s work with the Rogue Basin population is being replicated by partners in the Umpqua and Willamette Valleys in Oregon, and the Puget Lowlands in Washington. This work is being completed in partnership with American Bird Conservancy and the Center for Natural Lands Management. The Rogue Basin component of this project is funded in part by the BLM National Conservation Lands Management Studies Support Program, Charlotte Martin Foundation, Oregon Wildlife Foundation, and Friends of the Cascade-Siskiyou National Monument.
Range-wide Oregon Vesper Sparrow Project
Vesper Sparrows (Pooecetes gramineus) are found throughout the northern half of North America and Canada. In the Pacific Northwest, breeding populations of Oregon Vesper Sparrow (Pooecetes gramineus affinis), one of four subspecies, historically spanned from southwest British Columbia, western Washington and Oregon, to northwestern California. Breeding Oregon Vesper Sparrows have been extirpated from British Columbia and northwestern California. Due to these dramatic declines, the subspecies has been petitioned for listing as endangered or threatened under the U.S. Endangered Species Act. The population is estimated to be fewer than 3,000 individuals.
Collaborators are conducting field research to determine why this species has been in decline, and what can be done to turn these negative trends around. Klamath Bird Observatory, American Bird Conservancy, Center for Natural Lands Management, and a master’s student from Southern Oregon University (SOU) are tackling this unique opportunity to study Oregon Vesper Sparrows together, throughout the subspecies’ breeding range, in order to develop strategies for stabilizing and recovering populations.
The Vesper Sparrow is considered a “little brown job.” You know, those streaky brown sparrows and dull-colored females that we all struggle with identifying? If no one knows about this “little brown job,” how can it ever be protected? The story of the Oregon Vesper Sparrow needs to be shared with birders and non-birders alike. Local Rogue Valley community members were involved in an end-of-season Vesper Sparrow count in 2018 to help share the story about this declining species, and assist researchers in gathering information about fall dispersal and habitat use. Fourteen volunteers attended an education presentation on the Vesper Sparrow, and then spent a total of 76 hours in the field studying the Vesper Sparrows at Howard Prairie in August.
In 2019, we are partnering with Vesper Meadow Education Program (www.vespermeadow.org) to again recruit community science volunteers to assist with the project. Volunteers will spend time at Vesper Meadow, a beautiful upland meadow located on the high divide of Dead Indian Plateau about 30 minutes east of Ashland, OR, and help researchers look for and record color-banded birds – or document their absence. Community scientists will also visit several other meadows in the Cascade Siskiyou National Monument to determine whether individual Oregon Vesper Sparrows banded in 2018 have relocated to nearby suitable habitat this summer. This community science effort is supported by Oregon Wildlife Foundation and BLM National Conservation Lands Management Studies Support Program. If you are interested in participating, please sign up at https://www.vespermeadow.org/vesper-sparrow-monitoring or contact Jeanine Moy at jeanine[at]vespermeadow.org.
In 2018, Klamath Bird Observatory staff, interns, and a master’s student from SOU began in-depth monitoring of the Rogue Basin birds located at Howard Prairie, near Ashland, Oregon. This research is being replicated by partners in the Umpqua and Willamette Valleys in Oregon, and the Puget Lowlands in Washington – to get a picture of Oregon Vesper Sparrow population health across its entire range.
Jim Lawrence, 2018 KBO Field Technician, spent his spring mornings diligently watching Vesper Sparrows from his lawn chair. The birds arrived from their wintering grounds in late April and began to settle in for the summer. Jim witnessed them defending their territories and attracting mates, watched as they paired up and initiated nest building, and saw them incubate their eggs and raise their young. Jim recorded breeding pairs as they built 25 nests and reared 62 fledglings: the next generation of Vesper Sparrows. His efforts will help track reproductive success as well as adult and juvenile survival.