October 20, 2011
Fall Raptor Migration Monitoring
Field Location: Hayden Valley, Yellowstone National Park (TRANSLATION)
David Haines: I can see a raptor which appears to be a Cooper’s Hawk. I have used the silhouette, behavior and plumage to discern the species and age; it is north east of the observation point, traveling to the south east.
Jeep Pagel: Can you determine if it is an adult, or if it is in subadult plumage?
David Haines: It is an adult.
Lesley Henry: Is your Cooper’s Hawk moving past one of the more visible sighting points in the sky?
David Haines: No. You are seeing another raptor. The Cooper’s Hawk is moving at tree-line level in a steady and fast flight through the valley.
Jeep Pagel: Did you see the Swainson’s Hawk flying at a high rate of speed behind it on the same track through the Valley?
Leslie Henry: No. Is it still in your field of view?
David Haines: The Cooper’s Hawk is out of my view; please document it on our data sheet. I need to look at that other buteo, which I believe may be a Ferruginous Hawk. Also, there was a male American kestrel that was soaring near the Swainson’s Hawk. Leslie -- can you pick it up in your field of view?
Leslie Henry: Yes, I see the male American Kestrel; the Swainson’s Hawk you saw is a dark morph, and I have seen another Swainson’s Hawk; a light morph, near Mt. Washburn, and it was moving to the west to the roadcut.