Subject: Re: Contents of the Auk - October 1996
Date: Oct 24 11:50:29 1996
From: Alan G. Grenon - agrenon at kent.wednet.edu



> October 1996 (Vol 113 No 4) issue of The Auk, the quarterly journal of
>the American Ornithologists' Union.

>
>Consequences of an alien shrub on the plumage coloration and ecology of
>Cedar Waxwings. Mark C Witmer. pp 735-743. Orange, instead of the normal
>yellow, tail bands in waxwings is the result of feeding on fruits of
>introduced Eurasian honeysuckles (Lonicera morrowii and L. tatarica), a
>food with high rhodoxanthin content, when birds are in molt. Eurasian
>honeysuckles are widely established outside of cultivation in the NE
>United States. Ecological interactions between waxwings and these
>honeysuckles underscores the unanticipated consequences that exotics can
>have on native organisms. The extent to which introduced honeysuckles may
>influence the ecology and behavior of waxwings remains to be determined.
>

A presentation of this material at the A. O. U. meeting this summer did
_not_ establish a cause-and-effect relationship between this plant and
feather color. It showed a possible correlation, leaving many variables
undescribed and the hypothesised cause untested. I'd like to know if the
article provides more details. I've seen some older waxwing specimens with
orange tail tips. . . A dietary source of feather pigment should be easy
to test.

Don't get me wrong; you'll find few people more virulently opposed to
introduced organisms.

Alan Grenon
agrenon at kent.wednet.edu
Seattle