Sharon.

You basically have to train yourself. The way I did it was counting
waterfowl, probably the easiest because they sit fairly still. If you are
looking at a small group of birds, say under 20, count them. If you see
another group, guess how many are there, then count them and see how close
you were. Every time you see a small group of anything, guess the size,
count, then adjust your mental picture of 20 items. Eventually, you will get
pretty good at estimating groups of 10, then 20. If you are looking at a
larger group, try to figure how many sets of 20 are in it, then cont them
and check for accuracy. Do this for a while until you are fairly good at
estimating 50. Then when you see a larger group, guess how many groups of 50
are in it. Then work on estimating 100. Once you get 100 down, you can
handle most any flocks you will find by estimating the number of groups of
100 within the flock. When counting Snow Geese, good luck!! What I usually
do is estimate an area that contains about 100 birds, then extrapolate that
area over the area of the entire flock, and estimate how many squares and
the area that would contain 1000 birds, then count how many groups of 1000
are there.

Everyone has a different ability to estimate numbers - it just takes
practice - and don't be afraid to be wrong. You will almost always be
wrong - the key is to be close and consistent. If you can estimate
consistently within +/- 10%, you will be better than most.

Dana C. Rohleder, O.D.
Port Kent, NY
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----- Original Message -----
From: "Sharon Tierra" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, February 19, 2003 9:34 PM
Subject: Re: Crows, crows, crows


> I'm very interested in knowing how one goes about estimating the number
> of birds in an area when numbers are large.
>
> Sharon Tierra
> Brookline