Hello, Birders.
Yesterday, Tuesday, February 1st, while studying a flock of Canada Geese at
Waneka Lake, Boulder County, I reflected on the following two matters:
1. Despite all the reports, there are *not*, so far as I can tell, very many
Cackling Geese in the northern Front Range region (and probably elsewhere)
right now. I've seen small numbers (ones and twos and threes) on a few
occasions in the past month; but most of the time I'm out, I see zero Cackling
Geese. So what are all these small geese, then?? At Waneka, for example, I saw
one obviously large Canada Goose among 300+ distinctly smaller "white-cheeked
geese." To cut to the chase, almost all these birds are LESSER CANADA GEESE
(Branta canadensis parvipes).
The problem for us in Colorado is that we get both the small Canada Geese
("Lesser," or parvipes) and the large Cackling Geese ("Richardson's," or
hutchinsii). And here's an even bigger problem: At around the same time the
hutchinsii Cackling Geese are departing (late December), the very late parvipes
Canada Geese appear to be arriving (mid-December). So the synchronous turnover
creates the impression of a continuous presence of small geese. And indeed they
are all small geese! But they're not all Cackling Geese, not by any stretch.
Back on January 22, 2011, I estimated/quasi-counted geese in the following
numbers at Matthew T. Glasser Reservoir in Broomfield County: 2 Greater
White-fronted Geese, 7 Snow Geese, 1 Blue Goose, 1 Ross's Goose, 3 Cackling
Geese, 5 "large" Canada Geese, 2800 parvipes Canada Geese, 100 undifferentiated
Canada Geese (but not Cackling). I think those numbers are probably pretty
typical, with Cackling Geese representing about one-tenth of one percent of the
goose population after mid-January.
2. Canada Geese, like many other birds, are amazingly homeothermic (or
"warm-blooded"). Because of the extreme cold yesterday (not to mention right
now!), the moisture in the air was condensing and precipitating everywhere,
even in the wan, hazy, sunshine. One of the places the moisture precipitated
was on the backs of the geese at Waneka. And it just stayed there, accumulating
a good centimeter on the backs of many of the birds. Our instinct, I believe,
is to think, "Oh! Those poor birds must be so-o-o cold!" But it's the exact
opposite. They're so warm, so enviably warm, that they retain their warmth so
effectively that none of it escapes across their external surfaces. (Now, if it
was us humans out there, stark naked, the stuff would melt immediately on
contact with our skin, that is to say, for the 15-20 minutes before we
literally froze to death.)
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Ted Floyd
Editor, Birding
Blog: http://tinyurl.com/2g2staq
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