Date: 2/9/18 4:01 pm
From: Robert O'Brien <baro...>
Subject: [obol] Re: More (detailed) Crossbill Info and Questions
Well, I just got a tip on how both these species perched on the same
treetop.
The photographer set up the branch along a roadside where crossbills were
coming
for salt. A clever form of chumming I guess, wherein the chum doesn't show
in
the photo.

On Fri, Feb 9, 2018 at 12:17 PM, Robert O'Brien <baro...> wrote:

> I hadn't decided whether to post all the stuff below, given the possible
> waning interest in the Oregon *Crossbills of the Century* invasion,
> starting late last year. (only 17+ years so far though). But with
> yesterday's great observations and photos by Philip Kline (
> https://ebird.org/view/checklist/S42595651 ) I'll go ahead.
>
> There are a couple interesting images on the attached jpg that is scanned
> from hardcopies of the AOU's life histories Birds of North America (1996).
> 1. Note the two perched species are on exactly the same twig in these 2
> separate accounts. Look familiar?
> 2. WW Crossbill is reported to have had a breeding outpost in the
> Cascades!
> 3. Check out the Oregon Breeding Bird Atlas to the right.
>
> So, I contacted the author of the WW Crossbill life history. He was
> likely a grad student at the time of his original observations (1996) in
> the Cascades.
> 1996 was awhile ago and he has been Distinguished Chair in Ecology,
> University of Wyoming, for quite awhile now ( http://www.uwyo.edu/benkman/
> people.html ) . So, it's not surprising that in short order he sent me
> his notes from 29 years ago about this WW Crossbill 'colony'.
>
> *I saw the white-wings on 23-25 July 1989 in the Cultus Lake area,
> Deschutes NF. There were 15-20 of them doing a lot of singing and giving
> flight songs indicative that they were about to nest. They were especially
> common in an area of mature Engelmann spruce that was producing a large
> cone crop. I got the impression that they had recently arrived and over the
> time I was there they seemed to increase. Although I didn’t see nest
> building, based on a fair amount of time observing breeding white-wings
> (between 1982 and the spring of 1989) I am virtually certain they would
> soon be building nests.*
>
> He has continued to publish many articles on crossbills.
>
> His unrelated observations were not picked up in the fabulous Oregon
> Breeding Bird Atlas (Paul Adamus, primary author) of about the same
> period. The atlas map suggests possible breeding though in the NE Oregon
> Mtns based upon the few suggestive observations.
>
> So, this is ancient history, what does it mean today?
>
> 1. Crossbills are known to breed wherever they find themselves, any month
> of the year, given an adequate local food supply. (For instance, his
> Cascades observations and some in the BB Atlas). But, year-round breeding
> only occurs south of us. More northern breeding seems to be dependent upon
> day-length: greater than 10.5 hours. This will occur in about a week.
>
> 2. And, it's not just WW Crossbills. We have had several Red Crossbill *call
> variants* this winter. Farther south (Arizona) there have been 2 or 3 or
> more call variants in the same
> flying flock. Like Dave Lauten, I've always put these variants on the
> back burner and been rather skeptical, but I now have to admit 'it's for
> real'. And it isn't a recent observation/theory. But, will these
> variants return to some ancestral breeding location, or will they breed in
> Oregon?
>
> This is a once in a lifetime (Crossbill lifetime, that is) chance to find
> out. So, I'd encourage OBOLers (like Philip Kline) to continue to monitor
> coastal (or valley) crossbills for breeding. This is not an easy thing to
> do for WWs, given the reports in the Oregon BB Atlas, *and recording
> their calls would be imperative. *Doug Robinson has posted that he will
> be willing to identify recorded calls of Crossbills (Red or WW), so that
> makes it much easier. *Send them to Doug.* As Doug says, even cellphone
> recordings will work. And, if some OBOL birders can find a breeding
> colony, even if it's the local coast variant, it would be very interesting.
> Could there be a misplaced call variant in the breeding colony? That would
> introduce a fly into the ointment, for sure.
>
> Bob OBrien Carver OR (where I have only seen/heard crossbills once in
> many decades, and then just for an hour or so in late-summer, mature, loud,
> cone-popping Austrian Black Pines. They must
> not have liked this local abundance since they moved on, much to my dismay.
>
>
>
>
>

 
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