Re: [Tweeters] scrub-jays a mixed blessingThere is a journal article from about a decade ago that was looking at two bill-morphs of Scrub Jay. One ate acorns, the other pine nuts. I suspect they will evolve around here.

Hal Michael
Olympia WA
ucd880 at comcast.net
----- Original Message -----
From: Jesse Ellis
To: Daniel Brown ; Tweeters
Sent: Monday, October 20, 2008 6:31 PM
Subject: Re: [Tweeters] scrub-jays a mixed blessing


Tweets-


Lots of jays are dependent or co-dependent on some type of nut. Nutcrackers and whitebark pine, scrub-jays and blue jays and oaks, and possibly (to some degree) Steller's and some conifers. I've been wondering about the same thing with regard to the expansion of scrub-jays. Are there simply enough oaks around in the King Co. area now planted to support them? Or have they turned to other food source? If they still need oaks, then I suspect some bad masting years will cause them to move around a lot if they run out of food. Should be interesting in the future.


As for competition with Steller's, sure, they'll compete in Seattle. But Scrubs, because of their dependence on oaks and whatever other human sources of food they have, will probably not extirpate Steller's, and probably won't result in the elimination of Steller's even with Seattle and King Co.. Portland has both species.


There IS a paper out there though that showed that Steller's Jays were at the bottom of the hierarchy with respect to corvid foraging groups. When multiple species in Arizona were feeding simultaneously on the same acorns, Steller's did the worst.


Jesse


At 5:42 PM -0700 10/20/08, Daniel Brown wrote:
Having grown up with scrub-jays, I can attest that they are aggressive and opportunistic, and they will certainly prey on any eggs or nestlings they can find. But the local Steller's jays run amok in my Redmond yard every spring and they seem to commit as much mayhem and murder as I remember from the scrubs.


One thing to be said for the scrubs is that they are enormously entertaining--they're smart, curious, and flamboyant. You won't be bored if they do show up in your neighborhood.


Perhaps this has already been discussed here and I've missed it, but is there any reason to think that the range expansion of the scrub-jays is anything other than "natural"? That is, is it the result of increased plantings of non-native oaks in urban areas of Puget Sound, for instance? I'd be interested in what folks think...


Daniel Brown
www.danieljamesbrown.com






On Oct 20, 2008, at 4:51 PM, Dennis Paulson wrote:


Hello, all.


It's interesting to read all the enthusiasm for the scrub-jay invasion on tweeters. There is a saying to the effect "be careful, you may get what you wish for."

Friends of mine in Portland have scrub-jays in their yard, and they have learned to dislike them fairly vigorously. They are active birders and bird lovers (I'm protecting their privacy on purpose), but the scrub-jays have pushed them beyond the pale. The jays take the eggs and/or young of every open-nesting species that tries to nest in their yard, and they bully the other birds unmercifully, often seeming to purposefully (according to my friends, both of whom have scientific backgrounds) fly in to their feeders just to scatter all the other birds. I seem to remember the word "terrorists" being used.


So it may be a mixed blessing when scrub-jays colonize all of the King County lowlands, which they probably will. I'd love to see one in my yard, but that is tempered by all the stories I've heard. We already have a full complement of crows, effective nest robbers that they are, and adding scrub-jays to the mix may be hard on our local avifauna. Mike Donahue pointed that Anna's Hummingbirds, those other California immigrants, "know" scrub-jays in an evolutionary sense, but our local birds don't.


I can't be too grumpy, however, when I've just returned from a successful Hawk Owl hunt.


Dennis
-----
Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115
206-528-1382
dennispaulson at comcast.net






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Daniel Brown
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--
Jesse Ellis, Ph. D.
Neurobiology and Behavior
jme29 at cornell.edu
111 Mudd Hall
Cornell University
Ithaca, 14853


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