It sounds like a sad nature moment.

Netta and Dennis please don't take this personally:

As some of you may know, Cotoneasters are among the most invasive of alien
shrubs in at least western Washington, with at least 16 species of
Cotoneaster naturalized in W. WA including a couple of species that have
become quite common, they are increasingly replacing our native flora and
contributing to the demise of much of our native fauna, that in turn depend
on the native plants. These Robins will now spread the seed, scarified
(nicked) by the grit in their gizzards then packaged in fertilizer. These
Cotoneasters will replace natives of similar habitats.

I find the Cotoneasters (I believe they are mostly C. Simonsii) in
relatively dry, open woods (by Seattle standards) where some natives such as
Ocean Spray Holodiscus discolor would normally be common. I've noticed
Bushtit nests in Ocean Spray whose seed heads look much like bushtit nests
and may help to camoflage them. Their flowers are a favorite of Spring
Azure butterflies, both as a nectar source and as a larval food. They are
also a favorite larval food of our beautiful Lorquin's Admiral butterfly.
That's just the butterflies, only a tiny fraction of the insects, not to
mention all of the other organisms. Cotoneasters host fewer insects (here
in their non-native habitat) and will support fewer insectivores including
the birds . I understand that even our songbirds, that primarilly eat seeds
and berries as adults, primarilly feed their young caterpillars.

One more plant that grows best in this habitat is the Madrone Arbutus
menziesii, whose berries are a favorite of our declining Band-tailed Pigeon
along with most of our other berry eaters including Cedar Waxwings and
Varied Thrushes among others. Sadly, large flocks of Starlings often wipe
out most of the berries before the Band-taileds can get them.

That's just 2 of the many plants that Cotoneasters are increasingly
replacing.

So while the birds may enjoy the berries of alien plants like Cotoneasters
and Pyracantha they are sowing the seeds of destruction (at least
degradation) of their whole ecosystem when they poop them out. So if you
have these plants to feed the birds, make sure the birds have corks in their
cloacas. To grow them in your gardens is akin to raising and releasing
Starlings, except that Starlings may have reached a plateau of their
population, while Cotoneasters seem to be rapidly increasing.

Stewart Wechsler
West Seattle
ecostewart at quidnunc.net



-----Original Message-----
From: TWEETERS-owner at u.washington.edu
[mailto:TWEETERS-owner at u.washington.edu]On Behalf Of Netta Smith
Sent: Wednesday, December 31, 2003 2:05 PM
To: tweeters at u.washington.edu
Subject: robin invasion


Hello, tweets.

A few minutes ago I had a great nature moment.

Robins have been flying over the neighborhood all day, presumably searching
for food sources. Amazingly, I heard one in brief full song when I was
outside at one point.

But the exciting thing was when birds started falling out of the air into
my yard, their target a Cotoneaster shrub full of bright red, half-inch
berries. They dropped into it one after another, with birds constantly
coming and going and as many as about 10 present at once. I tried watching
individual birds, and it seemed that each one would eat about 10 berries
before it flew away. Some lingered longer, others gobbled up their berries
at the rate of about one per second, each berry disappearing instantly into
that capacious throat. The whole episode lasted less than 5 minutes, and
they were gone. This must be a common feeding strategy, but to see it so
intimately was quite a thrill.

A bit earlier, I had watched a Hermit Thrush feeding on the same berries by
jumping up from the ground beneath the shrub, grabbing a berry and
swallowing it, taking a little more time to get it down than the robins.
That's the first of that species I've seen in the yard this winter. I think
it also was feeding on millet that I had sprinkled everywhere, along with a
Varied Thrush, also the first I'd seen in my yard. Snow can bring good
birding.

And the same to all of you!

Dennis Paulson
--
Netta Smith and Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115

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