[obol] Re: shrike ID
- From: David Irons <llsdirons@xxxxxxx>
- To: paul sullivan <paultsullivan@xxxxxxxxxxxx>, linda Fink <linda@xxxxxxxx>, OBOL Oregon Birders Online <obol@xxxxxxxxxxxxx>
- Date: Fri, 27 Mar 2015 16:45:15 +0000
Paul Sullivan wrote:
I
wouldn’t say that most of the Northern Shrikes we see in Oregon are
immatures, i.e. the brown-colored birds. I’ve seen plenty of adult
Northerns. Carol
& I saw BOTH kinds of shrike in the same day regularly on our
winter raptor routes in Gilliam county over the last many years. We did
see BOTH species sitting up on power lines, too. (Gilliam county has
limited perches). Paul et al.,
I would caution that many of the Oregon Northern Shrikes that look like and are
identified as "adults" (strongly contrasting plumage with gray adult-like
upperparts) are actually first-winter birds if you look closely. By late
winter/early spring these birds will have transitioned into plumages that make
them look like adults. However, they will have worn retained flight feathers
that reveal their age. A good example of such a bird can be found at the link
below. Image #3
http://www.birdfellow.com/birds/northern-shrike-lanius-excubitor#/idPhotos
I too have seen "plenty" of adult Northern Shrikes in Oregon, but these still
represent a decided minority of all the Northern Shrikes (hundreds) that I've
seen over 40 years.
One behavioral clue that has not been mentioned is flight style. Northerns tend
to have a more undulating flight with more frequent breaks in wingbeats,
whereas Loggerheads fly with more rapid and constant wingbeats taking a more
direct flight line. I agree that both species will perch on power lines. I
think we are just more accustomed to seeing Loggerheads on power lines because
there are a lot more of them on the landscape (in season).
Dave Irons
Other related posts:
