Species Richness Variation

[Roger C. KENDRICK]

Here in Hong Kong, during the last two weeks I have run a moth trap
every
three or four days (well, nights!), weather (i.e. thunderstorms)
permitting. On the overcast, humid (>90% r.h.), calm nights, with the
temperature around 26 to 280C and occasional rain, the total number of
species seen (not including some "micro" moths) was in the region of 60
to 90. On the two nights were there wasn't a cloud in the sky, with
relatively low (around 70 to 80% r.h.) humidity (for Hong Kong in
summer), similar temperatures and little wind, the species counts
(excluding the same "micros") were 260 and 225 species!! No prolonged
extremely heavy rain was recorded during this period of time, a factor
that is known to cause a major drop in species numbers caught.

I find this observation of larger species counts on clear nights (albeit
from a very limited sample) a little surprising, as I would expect the
former conditions to be more likely to result in higher species counts
(based on previous experience in the U.K.).
Does anyone have any ideas as to why such high species counts occurred
on
relatively unfavourable nights?
Why was there such a large difference in the species counts?
Is this a phenomenon that is confined to the tropics?
Has anyone seen more than 260 moth species caught in one trap over one
night before?

Hoping for some possible answers.

(Thanks in advance for any answer to Leps-L, or by e-mail).

Roger.
________________________________________________
Roger C. KENDRICK
PhD student & Demonstrator, Dept of Ecology & Biodiversity
The University of Hong Kong
fax: (852) 24885285
mailto:kendrick at hkusua.hku.hk
http://www.hku.hk/ecology/dd/pgs/roger/hkmoth.htm Hong Kong Moths
mail: Kadoorie Agricultural Research Centre
      The University of Hong Kong
      Lam Kam Road, Shek Kong,
      Yuen Long, New Territories
      Hong Kong