numbers game or counting

[Michael Gochfeld]

Barb Beck wrote:

> The numbers game is played to give some estimate - admittedly rough as to
> the abundance of a particular species.  Sometimes large numbers of a species
> can be counted by one person.  Several I was involved in:

I agree with the fact that numbers are better than no numbers.  When I was 15 I
had to justify to my birding mentor why I bothered to count Robins on suburban
lawns.

However, numbers become more useful, the more qualifications and explanations
there are.  Thus the example of a flock of 1000 individuals plus  1 individual
would be published as a count of 1001.  This has been recognized as troublesome
for decades, and I always try to enter the proper estimates in my field notes as
1000 +/-100  +  1.  This would probably only be useful if I ever go back to try
to figure out status, even if the field notes ultimately got archived somewhere.

Nonetheless, putting an error estimate around numbers can be valuable.

Published census data are fraught with many possible errors (including
identification and including failure to recognize ones favorite taxon).

I agree too, that butterfly numbers are more variable than birds due to
phenology and weather conditions and events the previous week, month or  year.

Also individual counters may have particular preferences and spend more time
hunting for particular species or bothering to count the common ones. For
example, there are a lot more Cabbage Whites (at least in NJ) when you actually
count them individually, than if you just do drive by estimates.  That must be
more of a problem for less conspicuous species.

Michael Gochfeld


 
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