>I CAN'T COMMENT ON THE FIRST TWO, BUT I'LL TAKE A STAB AT #3.  NO, IT
>SHOULD NOT BE LISTED YET.  I WOULD TAKE THE WE HAVEN'T LOOKED HARD ENOUGH
>YET STAND.  CONSERVATIONALISTS AND OTHER BIOLOGISTS DO NOT NEED THE BAD
>PRESS CONCERNING THE LISTING OF A SPECIES THAT IS LATER FOUND TO BE
>THRIVING.  SNAIL DARTER AND OTHERS NIGHTMARE.  A SPECIES SHOULD BE LISTED
>ONLY AFTER THOROUGH SEARCHES HAVE BEEN MADE BY COMPETENT FIELD BIOLOGISTS.
>FOR INSTANCE, MANY LAND SNAILS ARE KNOWN ONLY FROM THE SMALL TYPE SERIES OR
>A UNIQUE SPECIMEN.  MANY ARE FROM OUT OF THE WAY PLACES WHICH HAVE NOT BEEN
>ADEQUATELY SURVEYED.  SOME OF THESE MAY INDEED BE ENDANGERED, BUT UNTIL
>SOMEONE LOOKS FOR THEM, WE CAN NOT SAY.
>
 
Although I agree with Kurt, there is more to listing an endangered species
than the number of individuals left around (at least in the USA). Number and
location of populations are equally important. For instance, you could have
thousands of individuals in a healthy, reproducing population- but if that
population could be wiped out by a single disaster, then they may be
considered endangered. As an example, there are several freshwater mussel
species in Ohio that only occur in the lower Muskingum River. Most of these
species are doing well, and some are quite common. The point is that they
are in one place, and one slug of pollution upstream could kill them all.
Thus, they are considered endangered by the State even though they are
locally common. But as Kurt said, a species should not be considered rare or
endangered until we have thouroughly searched for it.
 
 
*  G Thomas Watters               *
*  Ohio Biological Survey &       *
*  Aquatic Ecology Laboratory     *
*  Ohio State University          *
*  1315 Kinnear Rd.               *
*  Columbus, OH 43212 USA         *
*  v:614-292-6170 f:614-292-0181  *
 
"The world is my oyster, except for months with an "R" in them" - Firesign
Theater