Subject: Re. Common Nighthawks
Date: Jun 06 20:16:09 1995
From: Jack Bowling - Jack_Bowling at mindlink.bc.ca


Dennis Paulson writes:
>My slant on the decrease of Common Nighthawks has been that this was a
>fairly marginal species in western Cascadia in precaucasian days, because
>the climate just doesn't favor large numbers of appropriate-sized flying
>insects (this is the worst area for an entomologist in the lower 48,
>believe me). During the period of intense logging, the landscape opened
>up, and insects actually became more abundant. I suspect nighthawks were
>favored then, just like Lewis' Woodpeckers, bluebirds, and others. With
>the subsequent "succession" (all clearcuts were fated to be either
>second-growth forest or shopping malls), conditions became marginal or
>worse again. I wonder if the decline in Purple Martins may be attributable
>to the same things.

Growing up in Tsawwassen in the 60's and 70's, nighthawks were a common
summer bird as Michael stated. We equated the "mosquito hawks" with the
hot, hazy evenings of summer and eagerly awaited a male to "boom" near us.
My mother's side has a 4-generation lineage in the Fraser Delta: her mother
was born there in 1897 and her father arrived from Nova Scotia in 1909.
They wed and raised a family of three girls at the east end of the now 12th
Avenue in Tsawwassen. I remember asking my grandparents about nighthawks
and they said that they were common when they were young during the first
years of this century, too. Same for my mother and her sisters during the
20s and 30s. I have often wondered about their decimation over the past two
decades. Aerial spraying blowing away a favoured insect prey species? They
seemed to love the "flying ants" when they emerged. Sure was a lot of
aerial spraying for mosquitoes when I was a kid so don't know if it could
have been a causative factor (I can still remember the sickly sweet smell
of the spray, watching the bi-plane rolling as it pulled up from a run). Is
the change in habitat from bigleaf maple/alder and redcedar/doug-fir
habitat associations to one of suburbia the root cause? The logging of the
pioneer forest of the Tsawwassen peninsula began at the turn of the century
and was just completing at the time I was old enough to remember any of it
( I _do_ remember the huge Gr. Blue Heron rookery a couple of blocks away
from our house. The one with the terrible fish smell and the huge, noisy
squawking birds in the trees...and the one which split up and moved to
Point Grey and Point Roberts when it was logged). This coincided with the
completion of the Deas (George Massey) Tunnel under the Fraser R., thus
sealing Tsaw's fate as a booming bedroom community for Vancouver. This fits
in well with Dennis's theory of possible increased insect prey due to
opening up the forests. But if encroaching suburbia is the root cause of
recent declines, then why are nighthawks still common back east as Dennis
mentions? Lack of suitable nesting habitat as suggested by Michael? They
love to nest in open pine forest in the interior. Nesting on flat roofs in
suburbia (which they do commonly in Kamloops, B.C.) would keep them out of
the way of canine predators but would open them up to predation by gulls.
Is the ratio of gulls/sq. mile lower back east than it is in the Fraser
Delta? It certainly is in the interior of B.C. What was their preferred
nesting habitat on the coast? I think many nighthawks used to nest in the
semi-dune habitat along the various short spits that jutted into Boundary
Bay in the "old days". Too many suburbanites walking their dogs now for
that strategy to ever succeed. Were there any studies of the species done
on the coastal strip during the period when they were common? What of the
fossil history? What of their social history among the west coast native
tribes? How long has the species inhabited the coastal lowlands?
Post-Wisconson glaciation or before? Their long migration path suggests a
possible inhabitation before the last glaciation. Lots of questions. No
answers. I still spend many summer evenings here in Prince George watching
nighthawks coursing through the skies and it always takes me back to the
end of the school year, sitting on Spetifore's Spit with the mosquito hawks
tearing past my head. I really do hope that one day they will return in
numbers to the beaches of my youth.

,Jack

,Jack




Jack Bowling
Prince George, BC
CANADA
jack_bowling at mindlink.bc.ca