[Tweeters] Mast producing trees and Lewis's Woodpeckers' - aquestion or two or three or more.....

Jeff Kozma jcr_5105 at charter.net
Thu Nov 11 10:20:55 PST 2010


Tweeters

In the scientific literature I have read on Lewis's Woodpeckers (LEWO), it
is my impression that they are somewhat burned habitat specialists during
the breeding season. They take advantage of burned trees (snags) for cavity
excavation and the openness of burned habitat provides great opportunities
for aerial foraging of insects. In addition, insect populations often boom
in burns from 1-5 years post fire and in large burns, densities of LEWO can
be quite high, especially 3-5 years post-fire. This is mostly from Vicki
Saab's "Birds and Burns" work in Idaho and Montana, as well as other
researchers.

With my work on cavity-nesting birds over the last 8 years, I have found
that LEWO also utilize oak habitat for breeding (as others undoubtedly
state), often approaching semi-colonial nesting as pair density can be
pretty high. This is most noticeable at Fort Simcoe, and other areas of
Yakima County where I have seen LEWO around oaks (Naches River, Oak Creek
Wildlife Area, etc.). However, I have also found LEWO nesting in pure
ponderosa pine forest in the Wenas area (where densities are much lower than
in burns) as well as in burns such as the Mud Lake burn above HWY 410 and in
the Ahtanum area. Work in Colorado by other researches has found that LEWO
also breed in cottonwood riparian habitats. So, the species is quite
variable in habitats that are used for breeding. Essentially, these habitats
must be open, have good quantities of insects, and have abundant snags or
cavities. Birds that breed in oaks here are not using the acorns as food
for their young, but simply taking advantage of the abundant cavities oaks
(especially large trees) provide as well as the openness of oak habitat.

In winter, LEWO do rely on mast and are mostly associated with oak dominated
habitats here in WA in winter. It would be interesting to know if the birds
breeding here in oak habitat are the same ones that winter here. Or, do our
breeders move south (say to oak forests in Oregon and California) and the
birds that overwinter here are migrants from further north...and if so,
where do our breeders go. Telemetry study anyone?

Jeff Kozma

Yakima

jcr underscore 5105 at charter dot net



----- Original Message -----
From: "Kelly McAllister" <mcallisters4 at comcast.net>
To: "'Yelm Backyard Wildlife'" <yelmbackyard at gmail.com>; "'tweeters'"
<tweeters at u.washington.edu>
Sent: Wednesday, November 10, 2010 6:37 PM
Subject: [Tweeters] Mast producing trees and Lewis's Woodpeckers' -
aquestion or two or three or more.....



> For what it's worth, I'd like to see if I can get some people to comment

> on

> post-breeding season (September-October)occurrence of Lewis's Woodpeckers

> in

> oak woodlands in Washington. I gather that one of the primary arguments

> against the notion that a failed acorn crop has created some recent

> wanderings, is that many, probably most, of our Lewis's Woodpeckers don't

> nest anywhere near oaks.

>

> I've not had the pleasure to see Lewis's Woodpeckers very often. However,

> the more memorable sightings have been large numbers in oak groves near

> Lyle, two different locations, and both during the late summer/early fall

> period. I'm wondering if some or many Lewis's Woodpeckers might move to

> oak-rich environments after the breeding season.

>

> "Birds of Washington" describes the species as wintering in oak woodlands

> and dependent upon mast supply. So, it seems likely that birds arriving in

> their winter habitat, probably during August or early September, finding

> mast production low to non-existent, would have no choice but to move on.

>

> Kelly McAllister

> Olympia

>

>

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> Tweeters at u.washington.edu

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