Sunday, January 24, 2010

Rocky Mountain Arsenal Raptors

Every DFO birding trip I have attended has been taught me something, and yesterday's trip to the Rocky Mountain Arsenal National Wildlife Refuge was no exception.

The highlight of this trip came early, in the form of Ferruginous Hawks. The more common 'light' form is pictured above. That individual had apparently had a messy breakfast before we arrived. As is often the case though, a well fed hawk is a content hawk, and this one remained perched as our 10 person group got good looks from fairly close range. Just down the road we had another Ferruginous, this one was the first of the dark variety that I had seen.

That one did fly more quickly, giving me a great view through my bins, showing its white tail and wrists on the upper wing, and the light crescent underneath that forms between the Ferruginous' telltale wrist comma, and the dark leading edge of the under-wing present in this variety. Good looks on both, and chances to become familiar with identification points that I knew would come in handy in the future. Little did I know that I would get the chance later on that same trip.

This bird is a juvenile, light, Ferruginous Hawk. One other birder spotted it on distant branch, but its perch was obscured by branches, and we ended up walking a good distance around the tree to get an unobstructed view. We had eliminated immature Bald Eagle and Red-tail Hawk fairly quickly, but were trying to determine if this could maybe be a Rough-legged Hawk - (which would have completed our area buteo trifecta for the day). The light coloring of the head was what was throwing us off, and we couldn't get a look at the feet, or discern the line of the gape as we approached to make an ID. In the picture the gape is visible, but in the field it was not. The bird decided it had had enough of the people walking a semicircle around it, and flew showing us its wrist commas and confirming its identity for us. It was a great chance to practice checking the field marks we had studied only a few hours before.

In addition to the Ferruginous Hawks there were a number of other raptors on display, including Red-tails, Northern Harriers, American Kestrels, Bald and the Golden Eagle above. The pictures of both the Golden and juvenile Ferruginous had to be brightened a bit after the fact, but show id points well. For the Golden, note that the bill progresses from black at the tip, to grey, and then a yellow base. This individual was close to a pair of Bald Eagles and allowed a chance to compare the two species. The Balds perch at an angle, where the Goldens tend to be more vertical and have a shape like that of a perched hawk.

Birding at the Arsenal is always productive, 27 square miles of refuge in an urban area guarantees that. An added bonus of a group trip like the one I joined yesterday was the potential to get outside the small area of public trails and see the Bison herd on the premises. Each time I visit I think too much time has passed since the last, and can't wait for the next. It is one of my favorite spots, and has a story that shows that even the most devastated environments can not only be repaired, but can become treasures for wildlife.

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