Population/Resources/Release

[Kenelm Philip]

	I agree with Norbert Kondla that the 'balance of nature' is an
idea that's been oversold--things are less static than that image suggests.
I also agree that many other things besides resources affect population
size--I've seen it happen. On the other hand, you won't see sustained
population levels in excess of what the resources can support...  The
well-known fact that habitat destruction is a major factor in extinction
is a case in point.

> I am not aware of any literature that presents data for the release
> of 'extra' butterflies displacing others

See the paper I referred to: Dethier & MacArthur, 1964. 'A Field's
Capacity to support a Butterfly Population', Nature 201:728-729. When
extra larvae were added to the colony (a 25-fold increase), the result
was that adults the following summer left the colony--as was shown by
the presence of eggs on asterd along the road leading out of the field
involved. Unless only the added larvae produced out-migrating adults,
one may conclude that the extra butterflies did in fact displace others.

						Ken Philip
fnkwp at uaf.edu