Hi Tweets,

After crunching numbers from this summer, thought a footnote would
be in order, to a discussion that ran earlier this year, back in
June and July, a thread here on Tweeters regarding the
disappearance of Nighthawks from Seattle. At that time, I
remarked, based on several recent years growth of the Purple Martin
population, in Seattle, and elsewhere in the Puget Sound and Georgia
basins, that the abundance of flying insects should not be a
limiting factor for Nighthawks. (This particular observation was in
fact originally made by Dennis Paulson, back in October 2004,
after reviewing data showing another significant annual increase in
known nesting martin pairs, data collected by Kevin Li, myself, and
others.) It was pointed out, by Bob Altman, that martins were the
exception , regarding long term trends for populations of aerial
insectivores. The regional martin population has been steadily
increasing since nestboxes were widely introduced, beginning in the
1970s. The only limiting factor seemed to be nesting cavities.
Well, not so anymore. This year Purple Martins in the north Sound
experienced by far the worst year for reproduction in all the years
data has been collected, and the limiting factor seems to have been
the food supply. Last year, 2005, was an average year up to that
point in time, with pairs producing between three and four
fledglings . (The BC-WA average 1998-2003 was 3.4 young per pair.)
2006 by comparison was bleak, at 1.25 fledglings per pair, at 13
colonies in seven north Sound counties. A few examples, 21 pair in
Skagit produced 80 fledglings in 2005, this year 24 pair produced 19
fledglings. Six pair in Bellingham last year produced 27
fledglings, this year 8 pair produced 8 fledglings. Three pair on
Lopez Island fledged 13 young last year, this year four pair there
experienced total reproductive failure, cold eggs and dead young
when nests were checked on August 10th. Reports of low production
and nesting failure are also coming out of BC this year. To what
extent poor reproduction and failure occurred elsewhere in WA is
unknown, as what reports I've seen so far have been mixed. It is
also worth noting that none of the noted poor reproduction or
failure in WA was in any way due to Starling competition.

Will be interesting to see what happens in 2007, which could see
the first reduction in numbers of WA martin pairs since the nestbox
recovery began four decades ago.

Stan Kostka

lynnandstan at earthlink.net

Arlington WA