# dots on maps

[asolodovnikov]

Wednesday, November 03, 1999, 9:59:11 PM, you wrote:

BB> Does anyone have an opinion about how many dots (=distribution records) a
BB> map needs to be useful? Many of my species are known from only one or two
BB> sites, so a map of their distribution would probably be a waste of space and
BB> time (but maybe other people think otherwise?). How many locality records
BB> does it take to interest biogeographers?

In my opinion it depends on particular problem you solve. Of course,
like all extremities, maps of 1-2 dots sound like to be of little use.
But even such maps of very few dots maybe useful for understanding of
some distributional pattern(s) for the given taxon(xa). Imagine a set of such
maps when one have a task to understand some pattern. It is much
better than having just a set of records. Visual impression seems to be a
strong tool for analytical work. Besides, in the revisions it is
better to map all distributions to provide readers the material which
is easier to remember and pleasant to use. Very detailed
(with hundreds of dots) maps may be essential for understanding of the
biotopic structure of the range (I mean trends in lanscape/biotopic
distribution within some piece of the range). But dotting of all
records (especially for a well documented taxon) would sound as unnecessary on
a general map aiming just to show the range of taxon. No general standard
guidelines could be given for a process of mapping. Each time one should
look for the optimal compromise among aim of the map, its scale and design.
Other point: I think one should distinguish the difference between the "working"
maps (for oneself, for discussions etc.), and maps to be published. Better to
produce many (maybe more than needed) of the "working" maps, which would help one
to solve a problem and find the best scale and design, but then select few ones
(the best) to be presented in the final publication for others.

And of course, I quite agree with Dr. Neil Snow, that each record should
be vouchered. But list of recorded specimens and map, serving to somewhat different
purposes, should not replace each other, but complement each other.

This is written by a beginner, who published no one distributional
map so far, but made several of "working" ones, and used the published ones.
Interesting what can the really experienced researchers say on the
approaches of mapping?

Sincerely,

Alexey.
************************************************
Alexey Yu. Solodovnikov
research assistant and research entomologist, Ph. D.
Laboratory of Insect Taxonomy
Zoological Institute Russ. Sci. Acad.
Universitetskaya nab. 1
199034 St.Petersburg RUSSIA
phone: +7 812 3281212
fax:   +7 812 1140444
e-mail: asolodovnikov at mail.ru