Sunday, October 07, 2007

Owl Banding

On Saturday night (and Sunday morning), Karyn and I joined our local Golden Eagle Audubon Society chapter on a field trip to the Idaho Bird Observatory. The Idaho Bird Observatory is considered an important birding location for the Audubon Society. The Idaho Bird Observatory is located at Lucky Peak (The actual peak, not the reservoir below it that most locals would think about when hearing the term). The peak is the southern most peak in the Boise front and is a critical junction for bird migration before they cross a large expanse of desert to the south. The IBO bands song birds, raptors and owls at the site. Last year we visited for the song bird banding. There is a summary of that trip on my blog at Idaho Bird Observatory - September 4, 2006.

The trip up to the observatory is a steep 4 wheel drive road that climbs 2500 feet in 6 miles. We met as a group at the bottom to carpool up the hill. A few planned to camp out at the observatory, while most, including ourselves, were just planning a late evening. We arrived at the observatory in early evening while it was still light. The biologists took us on a tour of the operation before diving into the hot pizza that our trip leader had brought to them. They were happy for the pizza as they live on the peak for most of the late summer and fall. The temperature was quite cool, made much cooler by the 15-20 mph steady winds hitting the peak. At 7:30pm the biologists raised the capture nets and turned on the audio simulating the call of the Northern Saw-whet Owl. The Saw-whet is the primary Owl they catch this time of year as their other species, the Flammulated Owl passed through weeks ago. Our trip was planned to coincide with the expected peak migration of the Saw-whet. It appears that our timing was correct as they had recently been catching 3-4 owls per night. The night before our trip, they banded a total of 13 birds.

At 9:30pm we made the first pass through the nets. There were no captured owls. To stay warm Karyn and I, along with another woman from the group, decided to take an hour long hike down the ridge road. Despite the wind it was a beautiful hike in the dark. There were lots of stars visible and the city provided enough ambient light so we could find our way through the dark. On the 11pm net run we found 4 owls! All four were Northern Saw-whet owls. The owls were brought back to the banding station where all of the scientific measurements were made. The biologists explained their processes and answered questions for the group. The birds were evaluated for age, sex, and health. Sex determination can only be determined through measurements and is only 95% accurate. DNA is another method, but the team was not taking blood samples. We appeared to have 3 females and 1 male, a mixture of hatch years (born this year), a second year, and a 2+ year old. Age is very difficult to determine as well on these birds. The oldest bird appeared to have feathers from three different molts. All of the birds were healthy with a couple of them rating high on the scale of muscle development. The muscle development not only indicates health but likely implies that the owl has already migrated a great distance developing those flight muscles further. Once all the measurements were taken the biologists would set the owl on someones arm to allow the owl to recover from all of the probing before flying off into the forest. It usually took a minute or two and on a couple of occasions resulted in the owl lightening its load just before flight! They then silently took to the air flying up to a branch in the tree above us before moving on their way. While the biologists would be working all night, it was past midnight so we decided to forgo the next net run and head home.

The owls are beautiful creatures, fascinating to watch. As usual the process brought about my concern for its intrusive nature. I wish we lived in a world where this intrusive process was not necessary. Unfortunately, with more than 20% of the bird species on the planet threatened or worse, increasing our education on individual species is critically important if we hope to help them survive the continued onslaught of human activity. With that said, the team of biologists were very professional doing everything possible to reduce the stress on the birds themselves while helping us to help them. In all it was a very enjoyable evening. The bird observatory is open to the public so go check it out!

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Anonymous said...

What species of owls did IBO net in the 4 that you saw?

wolf21m said...

Stephany, all 4 were Northern Saw-whet owls. I will update the story to specify that. Thanks for stopping by.