Friday, October 2, 2009

Birds of Many Feathers

Toward the end of the summer, we hawk watchers found it increasingly difficult to tell which molting haggard (adult hawk) we were observing. Red tail feathers looked less brilliant, spots and mottles on their chests seemed to move around, and unless we were lucky enough to see both haggards at the same time when the size difference between the male (smaller) and female (larger) was apparent, we could only rely on trying to match up recent photos with earlier ones. Sometimes, a bird looked so different that we even wondered if a new haggard had arrived on the scene!

So, as always when these knotty hawk questions arise, I contacted John Blakeman and asked him if the birds' markings changed during the summer and as they molt.

John's reply:

"Right now, in September, the hags can look decidedly different from their near-perfect winter splendor. They are just now finishing their molts. The long flight feathers are probably already replaced and in perfect new condition.
But their body coverts, the small non-flight feathers all over their bodies are in horrible condition at this time of the year. Many of the coverts are new, in pristine dark brown coloration, without any ragged edges, but a lot of the lighter-colored, partially bleached and worn coverts yet remain. Additionally, at this time of the year a lot of the coverts have dropped out and are being replaced, leaving yawning gaps in feather continuity.

Right now, the birds can look pretty ragged and disheveled. This is really apparent on the head and neck, in many cases, but by mid October, all the feathers should be new and evenly colored, ready for winter. Dishevelment will have passed.

Even so, there can be moderate new feather patterns, especially on the chest and belly. As they get older, they tend to lose more and more of the remnants of the immature belly band. Old adults often have no dark markings on any part of their chest or abdomen, although that is highly variable from bird to bird.

--John Blakeman

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