butterflies of the "edge"

[Kondla, Norbert FOR:EX]

In the absence of some citations at my fingertips; I can offer the following
brief and incomplete thoughts:
- time and scale and stochasicity are of fundamental importance in ecology,
both autecology and synecology; change is the only constant so there is no
such thing as a stable biome and some biomes/habitats that appear to be
stable over short time horizons such as a human lifetime, actually consist
of a changing patchwork of various resources that organisms respond to
- in the example given below; was there sampling of a similar grassland
patch that was not located adjacent to a forest or an agricultural field --
to separate the influence of inherent habitat components vs influence of
position in the landscape relative to other patches?
- the primary drivers of butterfly location in space at a given point in
time seem to be thermoregulation, mate locating behaviour, oviposition
behaviour, nectar sources, sodium sources, wind, host plant location
- so from a behavioural perspective, mobile organisms can and do "opt" for
particular environmental attributes but from a population survival
perspective I doubt that there is any "opting" involved; the populations
simply persist where the suitable environmental attributes persist and the
populations go extinct when the right attributes no longer exist due to
natural or human-induced changes


-----Original Message-----
From: John Grehan [mailto:jrg13 at psu.edu]
Sent: Sunday, September 17, 2000 6:04 PM
To: leps-l at lists.yale.edu
Cc: smap at africaonline.co.ke
Subject: butterflies of the "edge"


The following is a modified email request from Smruti Damania for
information regarding butterfly behaviour and ecology that I am not
sufficiently familier with
to provide answers. If anyone on the list would like to provide information
on these aspects and any pertinent literature I am sure she would be most
grateful. She is not a member of the list (although I will suggest that she
might
like to join) so please send responses to her email address (but also post
on
the list if you think the points might be of general interest). John Grehan

From: "Damania" <smap at africaonline.co.ke>

I am a recent BSc. Zoology graduate from the University of Eastern Africa, 
Baraton. I am immensely interested in biological research and am an ardent 
butterfly enthusiast. While at the university, I had carried out several 
researches regarding the use of Lepidoptera as bio-indicators of different
biomes. 

According to my research, the greatest diversity of Lepidoptera were found 
in a sampling station that is a grassland patch lying at the edge of a
cultivated 
farmland. In my research, this 'edge' accounted for the highest distribution

class of Lepidoptera. Also, another interesting fact was that while
sampling in the indigenous woodland biome of my study area, I found
aggregates of Milkweed butterflies(Amauris albimaculatus) to prefer a
certain area within the biome 
where trees had recently been felled; and a path lay alongside. 

I am curious as to why the preference for living on the 'edge' should be so.

What exactly is it about the 'edge' that attracts butterflies to it? From my

observations, I found that the boundary zone between different biomes was 
much more preferred than within the biome itself. Why opt for the 'boundary
line' 
or the 'edge' ,as you call it, in preference to an established, stable
biome? 
I still cannot understand this, perhaps due to my limited knowledge on these
amazing creatures. 

In my research, A. albimaculatus, Papilio demodocus, Papilio dardanus, 
Papilio nireus and Vanessa cardui all show a preference to the 'edge'. 

What butterflies in America show a similar preference for the edge? 
Butterflies are still a relatively new field of study in my country, where 
conservation efforts tend to lean toward more economically profitable 
species.

Thankyou, 

Smruti. (Miss Smruti Damania, P.O. Box 975, Nakuru, Kenya)