[Birdtalk] Red Crossbills at Feeders
STEPHEN T CARLILE
carlilest at msn.com
Thu Mar 26 22:16:15 MDT 2009
I do remember. I was there with Mark and I was pretty impressed that he could "deliver" such a rare bird (and a lifer too for me) in such numbers. I can still remember how my neck hurt after watching them move through the trees.
Stephen Carlile
----- Original Message -----
From: Mark Stackhouse<mailto:westwings at sisna.com>
To: Birdtalk Birds<mailto:birdtalk at utahbirds.org>
Sent: Thursday, March 26, 2009 10:03 PM
Subject: Re: [Birdtalk] Red Crossbills at Feeders
I don't disagree with anything the Bryant says, except that the numbers of White-winged Crossbills is not unprecedented in Utah. About 20 years ago, in 1987 or 88, there was an irruption of crossbills that may have been even bigger than this year's (I can't say, since I haven't seen this year's - just judging from the reports you guys post). In May of that year, on a field trip to Brighton for the Field Ornithology class I taught at Tracy Aviary, we had several hundred crossbills all over the upper part of Big Cottonwood Canyon, with White-winged outnumbering Red by about two to one. Some of you "old timers" might remember it.
We didn't have nearly as many birders in Utah then, and no Birdnet, so I can't really say how extensive this event was, either geographically or temporally, but it was, and still remains, the most impressive crossbill irruption I've seen anywhere.
Mark Stackhouse
On Mar 26, 2009, at 9:43 PM, Bryant Olsen wrote:
I too have seen these cycles of boom and invasion with Crossbills before, and as a plant guy maybe I help shed some more light on the issue. Pines, and other conifer trees, have very erratic cone crop productions from year to year, depending on various factors such as snow pack, late frosts, and other less understood cycles. So the birds that specialize in feeding on their seeds, such as Crossbills and Pinyon Jays etc., have adapted a degree of adaptability not seen in many other birds. They will wander widely looking for a good crop, stay and nest,even in mid winter, and then move on once the crop is exosted or fails.
However, what has been happening to the conifer forest of the west, and the far north for that matter too, the past few decades is rather unprecident. After the worst drought in 500 years starting in 1999, and lasting until about 2005, many of our forests were severly stressed and beetle out breaks have destroyed vast acres of them on a very large scale that has never been seen before, which creates a lot of fuel for forest fires, which destroyes even more forests. Although the last few years haven't been as bad for water, the trees still haven't fully recovered, and the new stress of a warming climate, which increases beetle larvae survival rates, isn't helping. Basically what I am say is that what we are seeing may note be just another boom-bust cycle, but may actually be an invasion of birds from farther north looking, in desperation, for heathly conifer forests to nest in.
Which bring us to the White-Wing Crossbills. These are normally very rare and unusual in the Great Basin and Centrel and Southern Rockies, with only a few erratic reports of individuals. These Crossbill are specially adapted for sub-arctic spruce forests and never before have been reported so widely and in such numbers this far south. When I went to Yellowstone last summer they were everywhere, out numbering even the Red Crossbills, and I suspect this is were all of ours have come from. That many White Winged Crossbills only could have come from Canada. We simple don't have that extensive of spruce forests to produce that many. Also many of you may have notice a crash in numbers of many other conifer dependant species. Remeber how the CBC was missing so many "normal" winter birds that were seen in great numbers just the previous winter?
Climate change is real folks, and happening right before our eyes. But no need to panic, it has all happened before on the scale of geological time, and evolution will adapt and change species to new climates, sometimes suprizing quickly.
Sorry for the long rant. Just my personal fellings on what I have been obseving the past decade or so. I could very well be wrong.
Bryant Olsen
--- On Thu, 3/26/09, Mark Stackhouse <westwings at sisna.com<mailto:westwings at sisna.com>> wrote:
From: Mark Stackhouse <westwings at sisna.com<mailto:westwings at sisna.com>>
Subject: Re: [Birdtalk] Red Crossbills at Feeders
To: "Birdtalk Birds" <birdtalk at utahbirds.org<mailto:birdtalk at utahbirds.org>>
Date: Thursday, March 26, 2009, 2:59 PM
I remember some years ago when there was a great irruption of crossbills in Utah, much like you're experiencing now. When spring came around, I was seeing crossbills in the desert, among the joshua trees on the Beaver Dam slope, and elsewhere in the St. George area. I thought it rather odd, just like the current reports of crossbills at feeders where they've rarely, or never, been seen before.
But it all makes sense when you consider the biology of population dynamics, and the cycles of abundance. To over-simplify a bit, populations cycle upward as resources (such as food) increase, then when the resource collapses (also part of the cycle) this expanded population is left looking farther and wider for that resource. As birders. we see this as birds looking for food that show up in places you don't expect to see them, like your feeder.
I've seen red crossbills foraging in mats of seaweed on the beach in Washington. The only time I've seen Pinyon Jays on Deseret Ranch in Rich County is after big fire years in western Utah that destroyed large tracts of pinyon-juniper.
So what you all are seeing at your feeders is the tail end of a boom cycle for crossbills, where individual birds are casting about in a desperate search for food.
Enjoy those crossbills while they last - when I've seen this before, it was immediately followed by a crash, and several years of few sightings, even in prime habitat, as the population builds back up again.
We'll see this summer in the mountains, and next winter, if my read of this is correct . . .
Mark Stackhouse
On Mar 26, 2009, at 2:12 PM, Carl Ingwell wrote:
And don't forget Jeff Bilsky's F Red Crossbill at his feeder in Sugarhouse.
On Thu, Mar 26, 2009 at 1:58 PM, Kristin Purdy <kristinpurdy at comcast.net<about:/mc/compose?to=kristinpurdy at comcast.net>> wrote:
I've heard two reports of Red Crossbills at bird feeders in the past couple days. Arnold Smith in Morgan, Morgan County, has had Red Crossbills at his feeder this week for only the second time since he's lived at that location, which I think is about 1970.
Keith Evans had a male Red Crossbill visit his feeder today for the first time ever. Keith lives in South Ogden, Weber County.
Kris
_______________________________________________
Birdtalk mailing list
Birdtalk at utahbirds.org<about:/mc/compose?to=Birdtalk at utahbirds.org>
http://utahbirds.org/mailman/listinfo/birdtalk<http://utahbirds.org/mailman/listinfo/birdtalk>
--
Carl Ingwell
801-688-5017
_______________________________________________
Birdtalk mailing list
Birdtalk at utahbirds.org<about:/mc/compose?to=Birdtalk at utahbirds.org>
http://utahbirds.org/mailman/listinfo/birdtalk<http://utahbirds.org/mailman/listinfo/birdtalk>
-----Inline Attachment Follows-----
_______________________________________________
Birdtalk mailing list
Birdtalk at utahbirds.org<about:/mc/compose?to=Birdtalk at utahbirds.org>
http://utahbirds.org/mailman/listinfo/birdtalk<http://utahbirds.org/mailman/listinfo/birdtalk>
_______________________________________________
Birdtalk mailing list
Birdtalk at utahbirds.org
http://utahbirds.org/mailman/listinfo/birdtalk
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://secureserver.securesites.net/pipermail/birdtalk/attachments/20090326/312ebe87/attachment-0001.htm
More information about the Birdtalk
mailing list