Subject: inquiry via Leps-L (fwd)

From: "Henry M. Brodkin" <[email-masked]>
Date: Mon, 3 Apr 1995 23:13:52 -0700

I am forwarding this request to Leps-L.  Please reply directly to
Christopher at <[email-masked]> as he is not yet
subscribed to the list.
(also please put your replies on the list for those of us who
are interested)

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        Hank Brodkin <[email-masked]> Marina Del Rey, CA
                        33.58'24"N 118.27'39"W
 finger <[email-masked]> for information about the Calbird-L Mail List

---------- Forwarded message ----------
Date: Mon, 3 Apr 95 12:57:14-040
From: starr - christopher dr. <[email-masked]>
To: [email-masked]
Subject: inquiry via Leps-L

INQUIRY: RIODINIDS IN TRINIDAD & TOBAGO
For a biogeographic-biodiversity study of the continental island of
Tobago, I am comparing numbers of known species in fairly well-
surveyed groups of plants and animals with those known from the
nearby continental island of Trinidad.  Trinidad has 16 times the land
area of Tobago, and so far the numbers in a broad array of groups are
consistent with the biogeographer's rule of thumb that a 10-fold
increase in area entails approximately a doubling in the number of
species.  Relying mainly on Malcolm Barcant's 1970 field guide to the
butterflies of the two islands, and assuming that the two are about
equally well surveyed in all families, I have broken the butteflies
up into five convenient groupings, disregarding any residue that
doesn't fit into any of them.  The figures for numbers of species
recorded in Tobago:Trinidad are as follows:
four-footed butterflies 22:108
lycaenids 17:97
pierids 13:27
riodinids 11:104
satyrids 8:24.
These figures all fit in well with the overall pattern from many other
groups of plants and animals, except for the very low Tobago:Trinidad
ratio in the riodinids.  It is way off the curve.
I would be most grateful to anyone who could advise me whether the
figures for this family are in fact believable or should be discarded.
I note that in a great many groups of organisms the Tobago:Trinidad
figures must be rejected in advance, as we know that Trinidad has
received much more intense collecting effort than has Tobago.  This is
the case for practically every poorly-known group.  But is there any
reason to think that riodinids should be less intensely surveyed than
the other four groups?
Christopher K. Starr
Dep't of Zoology
University of the West Indies
St Augustine, Trinidad
[email-masked]