Wednesday, November 28, 2012

Fall Raptor Migration

The end of October brought the end of one of my fall projects - trapping and banding migrating raptors at the Idaho Bird Observatory. This year, with a lighter class load, I was able to spend more time on the mountain. I was up there at least 2 days a week and sometimes as many as five. It was a great time with a lot of great birds.

American Kestrel - Male.

In total, I trapped 16 days and banded over 220 birds. Between the two trapping stations (Lucky Peak and Boise Peak), our team banded over 1100. It was a pretty good year!

The highlight of the season for me had to be my solo trap of two juvenile goshawks at the same time.

Two juvenile Northern Goshawks - male left, female right.

It was all quite unexpected. I was trying to catch a Merlin, another favorite bird. They are fast and fleeting. The Merlin dove close to the "mist net" but pulled up at the last moment and flew on by. I twisted to see if it was circling back around when I saw a large bird hit the net! I didn't even see her. I ran out and extracted the first goshawk from the net. I often invite others to join me in the blind, but on this day I was working by myself. I returned to the blind to process the goshawk. As I sat down, another bird caught my eye. The other goshawk was going after my dove! I hadn't even pulled the lure. Holding the first goshawk in one hand, I leaned over and trapped the second with my only free hand. Yikes, what do I do now!?! I quickly put the first in a "can" as I ran out and retrieved the second. Awesome day and a great comparison of the size difference between male and female goshawks! The goshawk is always my favorite as I have spent the last 2.5 years studying them for my master's thesis in raptor biology. I caught a total of four this year.

While I am partial to goshawks, there are more rare birds to catch. While Swainson's hawks are common in our area, we have only ever captured three of them in 17 years of trapping. That is until I trapped the 4th this year.

Juvenile Swainson's Hawk.

This might have been a more exciting bird had I realized what we had trapped at the time. Without taking a close look at the bird, I originally identified it as a juvenile Red-tailed Hawk. I passed it off to be banded by an assistant, and I went on trapping. It wasn't until I saw the photos that it clicked. That was no Red-tailed Hawk! That was an important lesson that I will not make again!

Juvenile Red-tailed Hawk (one of eight I caught this year).

Merlins are always a favorite. I would catch a total of five this season. Like goshawks, they often commit to their prey from a distance out and come in hard and fast. We also have three possible sub-species that migrate through Idaho and it is always exciting to see what you caught. However, I have only even caught the primary sub-species - Taiga or Tundra Merlin - Falco columbarius columbarius.

Taiga Merlin.

During my first day of trapping this season, late in the day, I was visited by a unique American Kestrel. This male bird had all of the markings of a normal Kestrel, but lacked much color on the breast. A few times during the season, presumably this same bird, came by late in the day. Finally, on my last day of trapping, I got him.

Male American Kestrel.

The bird had normal streaking on the chest, but lacked much background color. Just two feathers had the expected buff color.

American Kestrel.

Sometimes we catch non-raptors. Last year Neil caught a Northern Shrike. This year, I was surprised by a Steller's Jay in my net!

Steller's Jay.
Steller's Jay.

It was a great year. I look forward to another one next season!

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