Oregon Vesper Sparrows are a declining and at-risk subspecies unique to the Pacific Northwest. This June, KBO’s Science Director Jaime Stephens, Research Biologist Sarah Rockwell, and volunteer Nate Trimble spent time in the field placing miniature GPS tags on Oregon Vesper Sparrows to discover their migratory routes and wintering grounds. We thought you might be interested in the process! (All photos and video by Nate Trimble unless otherwise noted.)
All that’s left is to hope he comes back next year! Because the battery weight needs to be light for a bird of this size, the tag is too small to transmit data; instead the data are stored on the device. This means each bird must be recaptured next year to retrieve the recorded GPS locations.
It’s suspected that Oregon Vesper Sparrows from the Rogue Basin winter in the Central Valley of California, but no one knows for sure. This is the first time this subspecies has been tracked throughout their annual cycle. The precise location information we will gain is critically important. This tagging project builds on nearly a decade of KBO’s work contributing to Oregon Vesper Sparrow range-wide research projects, in partnership with American Bird Conservancy and Center for Natural Lands Management, to better understand this subspecies’ population size and trends, as well as whether their populations are limited by factors related to the summer breeding grounds, overwintering grounds, or survival during migration. With a better understanding of where in the annual life cycle birds are experiencing threats, and how specific summer and winter geographies are linked, we can better identify conservation actions to halt and reverse the declining trend for Oregon Vesper Sparrow.
As this year’s nesting season draws to a close, we wish the sparrows good luck on their upcoming journey south. We hope to see many of them back at our meadow next summer!
(KBO’s Oregon Vesper Sparrow field efforts in 2020 were supported by the Carpenter Foundation, Oregon Wildlife Foundation, and Oregon Zoo’s Future for Wildlife Fund.)