I want to add a couple of notes in response to Stewart's post:

>
>Rufous Hummingbirds have apparantly declined as the range of the Anna's has
>expanded north, due apparantly to winter hummingbird feeding, and have
>become quite common, at least in the metropolitan area. Are they in any way
>responsible for the decline of the Rufous? I don't know, but I suspect so.
>Do Anna's defend their territories against Rufous, or compete for limited
>nectar? I'd like to know if and how Anna's may be replacing rufous, but I
>still love seeing the Anna's.

I have not read of any studies on this topic, but in my personal
experience, although Rufous and Anna's Hummingbirds overlap in their
range during the summer months, Anna's Hummingbirds tend to be more
reclusive and less aggressive than the Rufous Hummingbirds. Anna's are
smaller in numbers and concentration and in the summer months they tend
to disappear - especially if you cannot key out their distinctive calls
that can still be heard now and then in the summer months. In our Tacoma
yard, Anna's stop coming to feeders in the spring and summer months
before becoming regulars again in late August.

I would argue that development and its impact of wiping out hundreds if
not thousands of acres of edge habitat every year that would otherwise
offer blooms to feed hummingbirds is the leading local suspect in a
decline in Rufous Hummingbird populations. But in truth the situation is
much more complex than this, since habitat destruction along the entire
migration route and factors in the Rufous Hummingbird wintering grounds
are also major factors in the rise or fall of populations.
>
>In addition to habitat destruction, are Eastern Gray Squirrels an important
>factor, in the rarity of native Douglas Squirrels in metropolitan areas and
>in pushing the native Western Gray Squirrel to the edge of extirpation in
>western WA?

I would argue that the major factor in the relative rarity of Douglas
Squirrels and the near extirpation of the Western Gray Squirrel are
related and they are largely due to extirpation of the habitats that
these species depend upon. Here in Tacoma, Douglas Squirrels are not all
that hard to find if you take a long walk in the deepest portions of
Point Defiance Park or other aging second growth habitat, and if you can
find old growth habitat in the area you can also find the hungry little
native squirrels. Eastern Gray Squirrels prefer altered habitats,
especially urban and suburban habitats, and so the reason you don't find
Douglas Squirrels running around urban yards is that the habitat is
generally not suitable.

The Western Gray Squirrel is another story. This species is dependent on
Oregon white oak habitat that has all but been destroyed in Western
Washington. A small population of Western Gray Squirrel lives in an oasis
of oak and prairie habitat between Fort Lewis and the McChord Air Force
Base near Tacoma, but local businesses and a handful of government
leaders are hot to cut this oasis of oak habitat in half to create
something called the Cross Base Highway, which will likely complete the
extirpation of Western Gray Squirrels from Western Washington in order to
cut a few people's commutes by a total of 11 minutes.

Overall, while I do believe that feeding birds has an impact on the
numbers and mix of bird species in areas where people put out feed, I do
see the positives of bird feeding. Mostly, as Stewart wrote, it can turn
people on to the natural world around them and encourage people to learn
more about birds and habitat. In my case, I do have bird feeders. Natalie
and I are slowly transforming our urban yard into more native habitat
that will cater to birds and butterflies and other native creatures, and
we plan to phase out or cut down on using seed feeders slowly as the
habitat itself becomes more suitable. Natalie and I already keep a sloppy
garden and yard to draw native species, and more people should consider
doing so. You wouldn't believe the increase in insect diversity that
occurs when you let your yard and garden go a little wild. Tall grass,
rotting leaf debris, and native hedges and trees will go a long way to
draw more native creatures to even the smallest urban yard.

Happy birding!

Rob