Tweeters,

Dennis Paulson notes that he has rarely observed kleptoparasitism
(stealing of fish, in this case) of Ospreys by Bald Eagles. I guess it
all depends on where you live.

The Nicola Valley near Merritt, B.C,, centered on Nicola Lake, has at
least 30 nesting pairs of Ospreys (including several places where 3
pairs nest within sight of each other), 6 to 8 nesting pairs of Bald
Eagles, and kazillions of fish.

In this area (and in other areas such as Kootenay Lake in BC, Pend
Oreille and Coeur d'Alene Lakes in N Idaho, and the lakes of central
Oregon), watching Bald Eagles steal fish from Ospreys is a daily
event. It makes you wonder whether Ospreys that nest close to Bald
Eagle nests, and are harassed more often, have lower breeding success
than those nesting farther away. I'm not sure if anyone has studied
this.

At any rate, it is heartening to see how much eagles and Ospreys have
recovered from the bad old days of DDT and eggshell thinning. In 1980,
I knew of only one active Bald Eagle nest and 2 Osprey nests in the
Nicola, though there may have been a few others I was unaware of. Long
may eagles, Ospreys, and fish prosper.

Wayne C. Weber
Delta, BC
contopus at telus.net



----- Original Message -----
From: Dennis Paulson <dpaulson at ups.edu>
To: <tweeters at u.washington.edu>
Sent: Friday, April 23, 2004 8:27 AM
Subject: raptor rumble


> On my commute this morning from Seattle to Tacoma, a bit north of
> Federal Way, I saw way ahead of me a bird diving on another bird,
and
> I assumed it was the usual crow diving on red-tail, but then I
> realized the diver was bigger than the divee. Finally they resolved
> themselves into an adult Bald Eagle diving on an Osprey that was
> frantically trying to get out of its way. They were 3-400 feet up in
> the air at this time, really moving. I assume the eagle was after a
> fish the Osprey had, but I couldn't tell. I don't know if the two
> interact territorially or if it's always kleptoparasitism when the
> eagle is after the Osprey. I have read about this interaction for
> years but have rarely seen it.
>
> A few days earlier I was coming in to Seattle in late afternoon, and
> three Ospreys in a row were flying south along I-5 just opposite the
> stadiums. I have no idea what was going on there.
> --
> Dennis Paulson, Director phone
253-879-3798
> Slater Museum of Natural History fax 253-879-3352
> University of Puget Sound e-mail
dpaulson at ups.edu
> 1500 N. Warner, #1088
> Tacoma, WA 98416-1088
> http://www.ups.edu/biology/museum/museum.html
>