Subject: BIRDXXXX highlights (fwd)
Date: May 27 20:17:56 1994
From: "Byron K. Butler" - BBUTLER at YALEVM.CIS.YALE.EDU


On Tue, 24 May 1994 16:53:14 -0400 Ken Knowles said:
>What is the official status of chaffinch for ABA area lists. From what I
>understand all fo the sightings to date are regarded as escaped birds.Here
>
By chaffinch I assume you mean Common Chaffinch, Fringilla coelebs. On May 7,
1989 I had a male of this species turn up in my yard -- I then lived in
Orford, New Hampshire. As soon as I reported the sighting I received many
queries asking me to demonstrate that this bird was not either an escape nor a
ship-assisted bird. At that time "my" bird was only the 8th known record from
North America, the 5th from the United States, and the 1st for New Hampshire.
There was no evidence of the bird having ever been in captivity (i.e., no
feather wear characteristic of a caged environment, no leg bands, no evidence
of inbreeding etc.) and certainly no way to know if it had been ship-assisted.
Never-the-less, there were some who maintained that unless I could demonstrate
that the bird was not an escape or a ship-assisted bird that it had to be
regarded as such. I tried to learn as much as I could about the first seven
North American records to see if there was evidence of earlier escapes or
ship-assisted birds. I found no evidence at all that any of the North American
records of Fringilla Coelebs can be shown to be invalidated. In the absence of
such evidence, the most parsimonious hypothesis is that these birds got over
here under thier own power. I argued (and part of my arguement was later
published in "American Birds") that it is not appropriate to hypothesize a
bird is an escape or has been ship assisted unless one can produce evidence to
that effect and that it is incumbent upon those claiming such an explanation to
present that evidence. I do support the conservative nature of rare records com
mittees and do not fault them if they do not accept sightings of uncertain bird
s, however, when the committee goes so far as to suggest a bird is an escape or
has been ship-assisted when there is no such evidence, I believe it has acted
inappropriately. When I studied the records of this species I found no evidence
to suggest anything other than that these birds were here on their own, further
more, the majority (5 of 8 at that time) had been sighted during the spring
migration period in a temporal window of only a few weeks, it seems to me that
this current bird is also within that pattern.

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