Subject: Re: BT pigeons
Date: Mar 3 10:57:14 1995
From: Dennis Paulson - dpaulson at ups.edu


I offer a hypothesis, that Band-tailed Pigeons may have moved their winter
base of operations to cities where there are an abundance of seed feeders,
thus altering our perception of their numbers in different ways. I really
feel there are more in North Seattle than there used to be. Alan Richards'
bailiwick out in the boonies by Naselle could lose birds for the same
reason. I'm not stating there haven't been large-scale declines, but I
wish it were easier to be sure.

As winter numbers are probably very patchy in space and time, the way we
really need to monitor their numbers is by breeding-bird censuses, and I
don't know what those have shown. I believe they may have shown local but
not widespread declines in the species.

One of the most fascinating things I learned when I was scanning Northwest
Christmas bird counts for recent years was that BTPI is a locally common
winterer in western WA but not in western OR. I never came up with an
explanation for that.

As for their being associated with bigleaf maples, Andy, that would be a
good idea to check further. They certainly hang out in the maples behind
my house, but they are the only large broadleaf trees. They also sit in
the conifers, which don't furnish as many nice perches. I haven't seen
them eating maple seeds, which would be the only reason I would think they
would associate with them especially.

American Wildlife and Plants: A Guide to Wildlife Food Habits, by Martin,
Zim & Nelson, 1951, lists the following wild plants as eaten by BTPI in the
Pacific states: *** oak & cherry, ** dogwood & elderberry, * madrona,
cascara, salal, thimbleberry, & bearberry. Number of asterisks
proportional to importance. Pine, hawthorn, and blueberry occasional.
Note these are either acorns or fleshy fruits (they may eat the seeds of
some). No maple listed, and it is a very different seed from the others.
They also eat cultivated grains and garden peas among non-native plants.
For these data, 510 stomachs were examined by US Biological Survey
personnel, presumably mostly gathered from hunters and quite a few years
ago. This is an impressive sample size. Any Tweeter seen them eating
anything else, except bird seed? They vacuum up sunflower seeds and millet
impartially at my feeders.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416