Monty Brigham wrote:
> On another point are frogs in general disappearing? In my area of
> eastern Canada the chorus frog isn't as noticeable as years before. Your
> thoughts please.
Here in Georgia that's not the case, except for problems where sites get
bulldozed like the dry pond site near me. That one bit will probably
lower the county frog populations by many thousands if all species are
counted.
If anything we believe some frogs here are expanding their range. And
that's often man made. For instance, logging operations often produce
temporary small pools, and I believe the Barking Treefrog and some
others are utilizing those to move northward. I've documented them in
good numbers northward of the previous range in Georgia. Certainly a
major portion of the water used for breeding down here is man made one
way or another.
Another one that's thought to move some frogs around here is fish
stocking. Although most species don't do well using water that has fish,
some are being carted around as eggs/tadpoles in stocking operations.
I'm assuming a lot of the range expansion I documented in the study is
not real expansion, however. I'm mostly just finding them where they
have been but not noticed. The use of call survey is fairly new in
establishing frog ranges. In fact it's still getting official standing,
which is something I've certainly pushed forward. You will no longer be
able to talk about Georgia's frog ranges without dealing with survey by
call recording. I've produced more records than all the bodies in bottles.
Of all our frogs the Gopher Frog and the Oak Toad may be in decline. If
so, it's habitat changes or long term climate change. The Pine Barrens
Treefrog has yet to be documented in Georgia, but if you look at it's
known range it must be one that was, not too far back, continuous.
The midwest was the hardest hit of the US as far as I can tell. There
are numerous causes, many of which don't have much to do with us. Some
new fungus infections, long term climate changes and so on.
You are seeing what has been widely reported. In a number of parts of
the world. Initially reported as some sort of barometer of how we were
damaging the environment, detailed research has shown it to be far more
complex. And there is a lot of work to do. Part of the critical info
needed is real good documentation of the ranges. Much of that now is
being done by volunteers like me. Many areas have the equivalent of our
Herp Atlas survey. There is even a US one, though that's not well
thought out. Anyone who wants to contribute, what's needed is eyes and
ears. And some form of documentation. Check and see if there is a survey
in your area. You don't need to go at it as heavy as I, every report counts=
.
I'm not overly worried about the complete loss of frogs. But some
species will undoubtedly go. Or their range will change. Canada is
fairly marginal for frogs as a whole. The long, cold winters make it
tough to be a frog there. I'd expect even moderate climate variations
would make a big difference in distribution.
Note that actually seeing frogs is tough. If you want a better picture,
go out in the breeding season at night and listen. You need to learn the
calling patterns, some frogs only call for part of the night, etc. Some
of the chorus frogs here are early evening callers, others all night,
and some better late night. Most call better if it's just rained or is
raining. I've also had cases where they only called when a car passed on
the road. Our big chorus frog calling time is early season, from now to
about early April. Yours would, of course, be much later.
Walt
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