Grebe Tracking Study
Introduction
Western grebes are in serious decline in Washington State and are one of the species most impacted by oil spills in California.
Evaluation of post-oil spill rehabilitation and survival of grebes has been prevented by lack of suitable tracking capability. Subcutaneous VHF transmitters tear out shortly after implantation and early pilot studies implanting intracoelomic transmitters resulted in 100% failure.
A 2007 study by the Oiled Wildlife Care Network and the SeaDoc Society developed an intracoelomic surgical procedure that resulted in 86% survival of Western grebes. This field study will determine how long and how well Western grebes implanted with transmitters will survive after release. 10 healthy birds have been implanted with intracoelomic satellite transmitters using the new technique and movement and survival are being monitored post-release.
This should provide California’s oiled wildlife responders with a technique for capturing Western grebes on water and will provide significant advances for monitoring post rehabilitation survival of rehabilitated oiled birds. Also this new technology will permit biologists to study Western Grebe migration and for the first time, to be able to link winter foraging areas on the marine water with summer nesting location on freshwater lakes.
Keep in mind:
- No one has ever been able to implant transmitters in grebes and have them live this long
- The grebes are ONLY SWIMMING. (They fly just twice a year, to migrate.)
With luck, the implanted birds will live long enough that we can learn about their migration habits.
Update 3/18/12: The transmitter batteries have died in all the birds, so tracking is at an end.
Update 12/12/11: Bird #97617 flew south to the outer coast of California near San Diego. Crazy bird! This is unexpected, as we thought birds stayed put during the winter. See this bird's tracking page.
Update 11/7/11: Bird #97622 migrated back to San Francisco Bay on November 4th. To the best of our knowledge, this is the first recorded complete annual migration of a Western Grebe.
Update 7/15/11: One bird stopped transmitting in May, leaving three birds alive and transmitting. One of the birds, 97622, has migrated to Clear Lake. Take a look at the individual tracking page for bird 97622.
Update 3/18/11: We are down to 4 birds alive.
Update 1/28/11: Two birds have died since release. That gives us a 78% post-release survival rate, which is pretty good considering that previous attempts had 100% mortality rates.
For photos, video, and more information about the study, use the links below.
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