Dennis, Mike, and Tweeters,

I am certain that, in some parts at least of the Pacific Northwest,
the main fruit used by wintering American Robins is the
berries of the native Pacific madrone (Arbutus menziesii)-- a tree
that usually produces abundant fruit that often lasts all winter.

It is instructive to compare the numbers of wintering Robins on
the Christmas Counts at Victoria, BC (where madrone is abundant)
and at Vancouver, BC (where it is rare). In the last 10 years,
Victoria has averaged 5277 Robins on its CBC-- almost 7 times
as many as Vancouver, which averages only 790. This is so
despite the wide variety of non-native fruits available in Vancouver.
None of them seems as useful to Robins as madrone berries.

Every time I visit Victoria in the winter, I am impressed by the big
flocks of Robins, which are usually busy gobbling madrone berries.
However, it should also be noted that Victoria averages about 2 to 3
degrees F milder in mid-winter than Vancouver, and worms and other
terrestrial (or subterranean) foods may also be more available to
Robins there than around Vancouver.


Wayne C. Weber
Delta, BC
contopus at telus.net



----- Original Message -----
From: "Dennis Paulson" <dennispaulson at comcast.net>
To: "Tweeters" <tweeters at u.washington.edu>
Sent: Sunday, December 03, 2006 4:24 PM
Subject: [Tweeters] berry interesting


I wonder what the robins would have been eating 100 years ago. The
ones in my yard are scarfing down cotoneaster and yew berries,
neither of them native. I don't know of anything in the neighborhood
that would feed them now, and I don't suppose there would be any
around here (the worms are shivering deep underground). If you
subtract all the exotic berry-bearing trees and shrubs planted in
towns, the Pacific Northwest might not be able to support very many
fruit eaters in winter. How many people have robins or Varied
Thrushes feeding on native fruits around their houses?
-----
Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115
206-528-1382
dennispaulson at comcast.net