Subject: LEWIS'S WOODPECKER DECLINES
Date: Nov 24 06:00:56 2000
From: WAYNE WEBER - WAYNE_WEBER at bc.sympatico.ca


Birders,

The November 2000 issue of EARTHCARE NORTHWEST, the newsletter of the
Seattle Audubon Society, features a short article by Hal Opperman on
Lewis's Woodpecker-- one of the "Birds in the Balance" series. In this
very informative article, Hal speculates on the reasons for sharp
declines in Lewis's Woodpeckers both east and west of the Cascades
over the last 30 to 40 years.

Since many of you do not receive EARTHCARE NORTHWEST, I will quote the
paragraph on causes of the declines:

"No one cause accounts for the fact Lewis's Woodpeckers are
increasingly harder to find in their core eastern Washington range.
The dramatic decline of open, old-growth Ponderosa Pine forest; fire
suppression; selective logging; replanting with dense stand of young
trees; salvage logging after burns; mature riparian cottonwoods lost
to natural causes, but not replaced by regeneration because of flood
control, water diversion, or intense grazing; and abandonment of nest
sites near new construction of secondary residences all play their
part. Many causes, one culprit: humans meddling with the landscape."

Although all the factors mentioned by Hal probably play a role, he has
missed what I consider to be the most important cause of the decline:
competition for nest-sites from the introduced European Starling.

On the southern British Columbia coast, Lewis's Woodpeckers were never
very common, but they nested both around Victoria (mainly in and near
stands of Garry oak, also called Oregon white oak) and, less commonly,
around Vancouver. In both areas, the last recorded nesting records
were about 1962 or 1963, just about the time period when Starlings
were becoming an abundant breeding species. Since then, Lewis's have
been only a rare migrant on the B.C. coast.

In the southern B.C. interior, where Lewis's Woodpeckers were always
more abundant, they have undergone a dramatic decrease in breeding
range and in numbers since the 1960s. However, in the last few years,
the (reduced) numbers seem to have stabilized, and there were signs of
a small resurgence in 1999. The species has been placed on the
provincial "blue list" of species known to be significantly declining,
but not yet threatened or endangered.

Lewis's Woodpeckers nest mainly in two habitats in the southern BC
interior; riparian cottonwood stands in the valleys, and open areas
(especially burned areas) in ponderosa pine stands. The decline seems
to have mainly affected Lewis's in the valleys, where they face severe
competition from Starlings; the latter species is generally absent
from pine stands.

No detailed studies have been made in B.C. of Lewis's Woodpecker
ecology or on the effects of Starling competition for nest-sites.
However, in view of the known severe impact of Starling competition on
bluebirds, Tree Swallows, Purple Martins, Crested Mynas, and flickers,
both in B.C. and elsewhere in North America, it seems probable that
this is also a key factor in the decline of Lewis's Woodpeckers.


Wayne C. Weber
Kamloops, BC
wayne_weber at bc.sympatico.ca