In 2020, we expanded the project with the deployment of archival GPS tags to track migration and overwinter locations of Oregon Vesper Sparrows that breed in the Rogue Basin. We successfully captured 10 males at our Howard Prairie study site and placed GPS backpacks on them using a leg-loop harness. Because the GPS tags are very small, and the batteries are not powerful enough to transmit data, tagged birds need to be recaptured the following year to retrieve the stored data.
In 2021, we located and recaptured four of these GPS backpack-wearing males! Three of them had fully functioning tags with fall migration and/or wintering locations recorded, and we look forward to sharing these exciting new results soon. In 2022, we expanded this aspect of the study and tagged 15 more birds at our Rogue Basin study site, as well as worked with partners in the Willamette Valley to tag 10 more birds there. This subspecies has never been tracked year-round before, and our work will uncover critical information about the migratory routes and overwintering areas used by this imperiled subspecies. This will help answer a question essential for future conservation efforts – what challenges might these birds be facing during migration and winter? Do birds breeding in the Rogue Basin and Willamette Valley use the same migration routes and winter locations? If not, how might these conservation challenges differ for disparate breeding populations?
To read more about this effort and see photos, check out the Klamath Call Note blog at How to Track an Oregon Vesper Sparrow. Our GPS research was made possible with funding from the Carpenter Foundation, Oregon Wildlife Foundation, and Oregon Conservation and Recreation Fund.
2020 saw the installation of the very first Motus station in Oregon at the Vesper Meadow Restoration Preserve, supported by Montana’s MPG Ranch. The Motus Wildlife Tracking System is a collaborative research network using automated radio-telemetry arrays to study the movements of small organisms. Tags are small enough to be carried by birds, bats, and even insects. Motus tags emit a radio frequency that can be detected by a nearby Motus station anywhere in the world. Our ongoing research includes tracking local Oregon Vesper Sparrow movements using Motus technology at this site, and migratory movements as the western Motus network develops. Further, our Motus station will provide location data for other research projects, recording any tagged organism that passes by on its own migratory journey. The east coast has a well-established Motus network that has led to exciting new discoveries in animal migration. We are excited to be at the forefront of developing a Motus network in the western U.S.
In 2021 and 2022, we searched for nests of this ground-dwelling bird at Vesper Meadow and placed Motus-compatible LifeTags on 20 Oregon Vesper Sparrow nestlings that were nearly ready to fledge. LifeTags are solar-powered and emit a signal every few minutes during daylight hours for the lifetime of the bird. The automated “resighting” and location estimation from this new technology will help us study habitat use, movements, and survival of young birds during the vulnerable post‐fledging period, and explore the dispersal of returning birds to nearby meadows next spring. We set up an array of Motus nodes at Vesper Meadow to supplement our main Motus station there. Four of the nodes formed a mini-grid around two of the nests with tagged nestlings, and this will serve to pilot the use of this technology to track precise fledgling locations. We collected tens of thousands of detections of our tagged fledglings from the node network over the months of June – October, and we will analyze those data this winter. A handheld telemetry antenna and Motus nodes placed in nearby meadows will allow us to more easily find any tagged birds that disperse to other meadows in the future.
In 2022, one of the fledglings tagged in 2021 passed by the Motus station, pinging off the tower three times between April 24 and May 13. This was very exciting! Because this individual did not seem to stay in this area to breed, we likely would never have known it was there – and that it had survived the winter – without the Motus tag. In addition to enhancing our Vesper Sparrow research, the Motus station at Vesper Meadow has detected five Lewis’s Woodpeckers migrating from MPG Ranch lands in Montana, a Swainson’s Thrush, Western Sandpiper, and Semipalmated Plover that were tagged in British Columbia, and a Dunlin and Long-billed Dowitcher that was tagged in California’s Central Valley – so the station is assisting other researchers with their migration tracking projects as well! Our Motus station, node network, and tagging effort were made possible by MPG Ranch, USFWS, Oregon Wildlife Foundation, and private donations.