Hi Tweeters

An interesting sidebar to Eric Greenwood's post is that Common Nighthawks
(CONI) used to be fairly common nesting birds in downtown Vancouver BC until
they were extirpated as a breeding species in Vancouver city by factor(s)
unknown in the 1970's. Flood? Disease? Sunbathers on rooftops? No-one knows.
Mystery.

While standing at a 10th floor window in an office building in downtown VCR
BC a few years ago, I noted window washers attempting to fix some gear on a
gravel rooftop below me were being harassed by a pair of Glaucous-winged
Gulls (GWGU). I looked for the chicks and saw them cowering against the
parapet on the side of the roof opposite to the workers.

Click.

In the late 1960's what passes for regional government here drastically
enlarged the VCR Landfill in Burns Bog, to the S of the city. One effect was
a massive increase in the GWGU population over the next decade. They began
to nest on gravel rooftops all over the city, among many other locations.
The CONI, being our latest migrant, would arrive back here about June 01 to
find the gulls already in possession of 'their' rooftops. End of CONI as a
locally breeding bird.

Has anyone else noticed similar large drops or extirps in other communities?

Michael Price
Vancouver BC Canada
michael_price at mindlink.bc.ca