Original message: Molecular vs morphological avian systematics

[Martin Bailey]

> Avian evolution A wild goose chase
> Jan 31st 2002 From The Economist print edition

"Canada-goose..... a species that farmers and park-keepers around the
northern hemisphere regard as a pest. "

 I am bemused that the Europeans call the Canada Goose a pest.

After the Second World War it was felt that the Canada Goose was on the road
to oblivion.  A captive breeding and release program was started at Regina,
Saskatchewan in the 1950's with aspects of it continuing into the 1990's.
It has proven to be very successful.

It is a sort of revenge for the release of European birds into North
America.  English Sparrows - now called House Sparrows - spread out from the
American seaboard in the early 1900's reaching Saskatchewan in the late
1920's.  Some say that it displaced native sparrows.  The reality is that
the native birds were adapting themselves to manmade structures that were
not there before white settlement.  Now they had to compete for these
structures with one more bird.

Today House Sparrows are on the decline and House Finches - released on the
east coast in the 1940's - have arrived here and are on the increase.  ( I
am sure that some whizz kid can find a statistically significant  inverse
correlation between the decline of one bird and the increase of the other.)

Probably what is happening is that Merlins(a native falcon) have started to
nest in towns here and find House Sparrows easier pickings than that other
import - the House Finch.

Using this information as a backdrop, is there any proof that the release of
captive bred butterflies results in competition for food with already in
place butterflies?  If not, what is the problem with another species finding
a niche in an already man altered environment?  Not all releases of non
native flora or fauna into new environments has proven catastrophic.  Many
we enjoy.

Martin Bailey,

greetings from:  Weyburn, SK., Canada.
                         49.39N  103.51W


 
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