From: "John Hartog" <>
> I like recording frog sounds. (That's a start) I do not know too
> much about frogs that are going extinct, but I have heard that
> various frogs around the world have shown drastically declining
> numbers in recent years. Some say frogs can be good indicator
> species, kind of like the canary in the coal mine, and that their
> decline can correlate to a decline in overall ecosystem health. I
> don't know how they sort out correlation and cause, but it must be a
> fascinating field of work. I do not know what a nature sound
> recordist in Portland Oregon, can do to help with this field of
> work. But if anyone knows of any frog studies going on near here, I
> would love to know.
> John Hartog
The most critical need is survey. We know so little about actual
populations of frogs or their distribution. Often the only data is from
folks that looked during the day, the worst time to survey frogs. In a
great many cases there is not enough data to establish baseline
populations to start investigating decline. Surveying frogs at night by
recording calls is about the most effective survey technique. Using
that, I made major differences to Georgia's frog distribution maps. All
expansions of range. While I think there are some range shifts going on,
exploiting human activities to expand range, I think most of the new
areas I put on the map were always there.
It takes massive amounts of time, for which there is no money. Just the
place for volunteers to help. The same need is true for almost any group
of animals that are not targets for hunters, or fishermen.
Hunt up the section of your state's DNR that deals with frogs, here in
Georgia it's a very underfunded section on Non-game species. Talk to
them, they will probably know what volunteer activity is available. If
there is a herp survey going on, volunteer. Then get out and see if you
can bury them with reports. Believe me, they will love it if you do good
work.
There is a national call survey system you could volunteer for. I don't
get involved with it because their methodology is extremely flawed. A
very rigid system of routes, prescribed survey dates and times all
combine to insure they will miss most frogs. It was obviously set up by
looking only at a statistics book. No biologists appear to have been
consulted. Certainly no one with my experience with calling frogs. Worst
is that's the survey that the feds will probably make decisions on.
You can find most of these activities on the internet, or in the local
paper if you happen to look on the right day.
Considering many places I've found frogs successfully breeding, I'm not
so sure about environmentally sensitive. Oily, junk filled swamps, mine
pits and tailings. They seem to be able to use most quite successfully.
Only place I saw failure was some kaolin mine pools. The frogs bred, but
the water was so low in pH that most species tadpoles could not survive.
The population of frogs in that area is high, and not changing, so there
must be enough ok water as well.
One of the big problems is far too many think correlation and cause are
the same thing. Correlation only gives you some ideas where to look for
cause. When you find that it won't be correlation, it will be some
chemical pathway or whatever. Sometimes I think a course in statistics
should be required for everyone. Every course I had was very clear on
the difference between correlation and cause. And that statistics was
really only able to give you correlation.
Walt
________________________________________________________________________
________________________________________________________________________
"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
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