Hi Bill and Tweeters:
I sent your interesting msg to Dave Wurzbach, an Osprey expert who lives down in the Chehalis area. Here is his answer about this behavior.
Yours, Carol Schulz
Des Moines
(There still are some Ospreys around here that haven't flown south.)
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>From Dave Wurzbach:
Carol,
You can pass this on to Mr. Anderson, or to whomever.
Dave

This behavior has often been misinterpreted as a form of hunting, but in fact it's the very behavior that sparked my interest in studying these hawks thirty years ago. What the bird was doing was was washing its feet by dragging them through the surface of the water after finishing a meal. It's not a behavior that is seen a lot and certainly isn't carried out by all Ospreys after every meal. I've witnessed it on half a dozen occasions.

This behavior is nicely described on page 370, in Arthur Cleveland Bent's Life Histories of North American Birds of Prey, book one of two books, in the chapter titled "American Osprey". This behavior is curiously missing in Alan F. Poole's book, "OSPREYS (A Natural and Unnatural History)".

It's also described in one sentence, "Often drags feet in water after feeding, presumably to clean them (perhaps also cooling)" which is located at the top of page 16, in the chapter on OSPREY, in "The Birds of North America, No. 683" a major undertaking to describe the life histories of all of the breeding birds of North America, which can be viewed on line - for a fee. (Notice that the authors wouldn't totally commit and protect their credentials by inserting presumably).

Female Ospreys are also known to wet their under parts during very hot weather (hmmm, that didn't sound quite right). They then return to the nest to cool their hatchlings with their wet plumage.

Dave Wurzbach



From: Bill Anderson
Sent: Thursday, September 15, 2011 12:16 AM
To: tweeters at u.washington.edu
Subject: [Tweeters] Edmonds osprey (9-13-11)


Last week I photographed an osprey skimming over the water below Sunset Ave. in Edmonds at sunset. Tuesday afternoon (9/13) I photographed similar behavior that I cannot explain, only document.
The osprey approached the Edmonds underwater dive park at Brackett's Landing from the north and started a long, low south bound swoop of the dive park. While making the swoop, the osprey would get down to water level and drag its feet along the water, making a rooster tail. At times the osprey was so low that it apeared its breast was scraping the water. It would pull up a little, then once again descend to water level and repeat the foot dragging.
Over an elapsed time of about a minute, the osprey made ten of these foot dragging, rooster tail generating, mini-swoops during its long swoop of the length of the dive park. When it reached the ferry dock it flew up and over the pedestrian bridge to the ferry and continued flying south.
For the past three summers I have photograhed many osprey patroling Puget Sound off Sunset Ave. for fish. I don't believe this osprey was hunting. The typical osprey hunt I have photographed consists of the osprey circling high overhead and then hovering above a target before diving. At the risk of anthropomorphizing, I would say this osprey was playing. A kid on a water slide came to mind.
If anyone has an explanation for the osprey's behavior, please reply to Tweeters as I am sure there are others in Tweetsterdom who would like to know what was going on.
Bill Anderson; Edmonds, WA. USA