Larry and Tweeters,



The Christmas Bird Count was not designed to keep track of changes in bird
populations, and cannot do so with any statistical accuracy. On the other
hand, the Breeding Bird Survey was, and does. As someone who has taken part
enthusiastically in both projects since the 1960s, I have far more faith in
the BBS as an accurate indicator of changes in bird numbers than the
Christmas Bird Count.



Of course, the BBS and the CBC are trying to measure two different things:
numbers of breeding flickers, versus numbers of wintering flickers. It is
quite possible that flickers could be declining as a breeding bird in WA,
but increasing as a wintering bird, as most of the flickers that winter in
WA breed in BC or areas even farther north.



Let's have a look at BBS results for Northern Flickers in WA, using the
tables that I referenced in my earlier message. From 1968 through 2007, the
BBS data in fact suggest an annual increase of 0.9% per year in WA. (WA is
one of only 4 states which show an increasing trend in flickers; the other
45 (there are no flickers in HI) all show a DECREASING trend, which is
statistically significant in most of them. Even in WA, the apparent increase
is NOT statistically significant, which means we cannot say for certain that
it is different from zero.



In the U.S. and Canada as a whole, flicker numbers (including both Northern
and Gilded Flickers) decreased by an average of 1.8 percent per year from
1966 to 2007-an alarming rate of decrease. If this number is accurate, it
means that the North American flicker population is about 45% of what it was
in 1966, or a decrease of 55%.



It is true that the steepest declines are in states east of the Mississippi.
However, the average rate of decline was 1.1% per year in both Oregon and
California, and was statistically significant there. In British Columbia,
there was virtually no change over the 41 years (average decline of 0.1%,
not significant).



Should flickers go on a "special concern" or "candidate" list, either
federally or in Washington? Probably not-despite the declines, they are
still commoner everywhere than Pileated Woodpeckers. However, what I was
trying to do in my message was to contrast Pileated Woodpeckers, which are
increasing practically everywhere, with flickers, which are declining
practically everywhere.



Wayne C. Weber

Delta, BC

contopus at telus.net









From: Larry Schwitters [mailto:leschwitters at me.com]
Sent: December-07-10 1:39 PM
To: Wayne Weber
Cc: TWEETERS
Subject: Re: [Tweeters] "State Candidate" species in WA



Wayne and Tweeters,



One might speculate that a lot of the concern for Pileated comes from low
numbers and habitat loss.



Northern Flickers decreasing in Washington State? Not according to the
Christmas Bird Count Data. http://audubon2.org/cbchist/table.html

The British Columbia Christmas Bird count data also indicates significant
Northern Flicker increases in the last twenty years.



Larry Schwitters

Issaquah