Subject: 04-04-97 Another Quick Check of Des Moines, WA Marina
Date: Apr 5 12:21:03 1997
From: Maureen Ellis - me2 at u.washington.edu
There is a foot-trail that goes midway along the bluff-side just above
the beach houses and a little north of the Des Moines Beach Park. A
quick late afternoon check in that lovely, quiet forested area was
rewarded with a leisurely view of our drabbest looking, drabbest singing
warbler. Peterson's Western Bird guide describes its song as "a weak
colorless trill, dropping in energy at the end." A good description, I
guess, but our first Orange-crowned warbler of the season was just
beautiful against a sunshiny bright blue sky and its song delightful.
RE: Recent discussion about Brant geese foraging....................
I did some literature research in Bent's on Brant geese diet preferences.
Most of the observations reported were of USA East Coast populations
with minimal specific information on what our NW Brants eat. Along both
coasts, of course the eelgrass Zostera marina is a major part of their
diet and also an alga Ulva lactuca plus other species of algae.
Additional things eaten include crustaceans, small mollusca, worms, and
marine insects. On their Arctic breeding grounds they have been seen to
eat land grasses and stalks/leaves of various flowering plants such a
Ranunculus and Saxifraga plus mosses and black lichens (those growing on
the upland rocks of high north places like Baffin Island.)
With regard to eelgrass, Brant are known to pull up much more than they
can eat when it is within reach depending on the tide depth. The excess
grass forms large floating mats which may drift a good distance off shore.
The geese can then consume these during high tide in relative safety from
shore-bound predators. I'm sure there must be more recent (than the late
1800's reports in Bent) studies of Brant foraging requirements. Perhaps
some our Tweeters who work as wildlife professionals or any of our astute
amateur ornithologists who have may have been watching these geese for
years can comment (I have less than five years experience with NW
seabirds.)
It's a beautiful Saturday and on my way down to the Marina.
Maureen Ellis me2 at u.washington.edu Univ of WA and Des Moines, WA