Wayne,

Thank you for that bit of information that points towards the loss of roof
nesting sites as only a minor factor at best in the decline of our (once
Common) Nighthawks (at least in Vancouver BC). I certainly appreciate your
input on this issue near and dear to so many nature enthusiasts hearts. As
you admit, your knowledge of insect populations is more limited, so I have
to suspect this may be a factor in why you have the impression that avian
predation is a substantially more important factor than decline in preferred
food insects. I certainly don't know what percentage either of these
factors are in that decline. While it seems very likely that increases in
avian predation is indeed one important factor in the equation that has led
to the loss of much of our former Nighthawk population, I have yet to see
evidence that it is the main factor. I encourage people to look further
into evidence whether declines in preferred insect food species in the
nesting range of the "Common" Nighthawk is a critical factor in the decline
of the Nighthawks over much of their range and how important increased
lights at night has been in the decline of those insects. Do we have
examples of where crow and gull populations or other avian Nighthawk
predators have not increased, yet there has been a similar decline in
Nighthawk populations. Has cat predation increased and is that one of the
limiting factors in the Nighthawk population? I'd also like to know of any
other factors that have led directly or indirectly to the decline of our
"Common" Nighthawks.

Stewart Wechsler
Ecological Consulting
West Seattle
206 932-7225
ecostewart at quidnunc.net

-Advice on the most site-appropriate native plants
and how to enhance habitat for the maximum diversity
of plants and animals
-Educational programs, nature walks and field trips
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-----Original Message-----
From: Wayne C. Weber

"...The ground-nesting nighthawks have disappeared around
Vancouver just as thoroughly as the roof-nesting ones. So
it looks to me that although loss of nesting sites may be a
minor factor in the disappearance of nighthawks, increased
avian predation is the main factor. ..."

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