[CT Birds] Common Birds in Decline in Connecticut
PCOMINS at audubon.org
Fri Jun 15 13:01:38 EDT 2007
That is a good point and I certainly agree that this is a potential
factor, but I also think that habitat changes and perhaps other factors
are at play because the declines are spread out over rather large
geographical areas, within which I think there would be variation in the
outbreaks of gypsy moth caterpillars:
Over the same period orioles have declined by nearly one percent
annually throughout USFWS Region 5 (Maine to Virginia) and at 0.7%
annually range-wide. Those numbers may not sound significant, but over
a 40 year time period would add up to substantial declines range-wide.
I did end up removing Black-billed Cuckoo from our list of focal species
for this reason. I have no doubt that they have also undergone
substantial declines over this period as well, but I thought that
perhaps the exact numbers were less reliable because of the natural
fluctuation in cuckoo numbers from year to year.
I do think that perhaps orioles are recently becoming more adapted to
suburban habitats, but compared with how common they were in
agricultural areas in the late 60's and early 70's and how much rural
and agricultural habitat we have lost, I don't think it is a stretch
that they have declined to the extent that the BBS data shows.
I know that in Manchester for one microcosm of the state, nearly all of
the scrubby edge areas that were productive for edge and shrubland birds
on the Summer and Christmas Bird Counts are now manicured high end
housing developments. So, while I think that gypsy moths may have
played some role in this and also the widespread spraying for moths in
the 70's could also have played a role, I also still think that loss of
nesting habitat is the key factor for all of these species.
Patrick Comins, Meriden
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