Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!iuvax!mailrus!ncar!boulder!sunybcs!dmark
From: dmark@cs.Buffalo.EDU (David Mark)
Newsgroups: rec.birds
Subject: RE: range expansions
Keywords: birding, bird-watching
Message-ID: <8903@cs.Buffalo.EDU>
Date: 31 Jul 89 13:06:15 GMT
References: <8863@cs.Buffalo.EDU> <390@mit-amt.MEDIA.MIT.EDU>
Sender: dmark@cs.Buffalo.EDU
Reply-To: dmark@sunybcs.UUCP (David Mark)
Organization: SUNY/Buffalo Geography
Lines: 33

In article <390@mit-amt.MEDIA.MIT.EDU> geek@media-lab.media.mit.edu (Chris Schmandt) writes:

>Well, one of my favorite topics is range expansion (range decline is all
>too common!).    Like the mockingbird, which now winters over here (Boston),
>yet back in Mark Twain's day was referred to as the "catbird of the south".
>
>Over the last 5 years I've been watching Turkey Vultures move (back?) into
>eastern Mass.  ... [etc.]

Cardinals have been another northward range expander.  A hundred years ago, 
almost the only place one could find them in Canada was in extreme southern 
Ontario, near Point Pelee.  By the 1930's, they were common in southwestern 
Ontario, but were rare north and east of Toronto.  In the late 1970's, they were
a hotline item in Ottawa and rare in Montreal.  Now they are uncommon but 
regular in those areas.  Urban heat islands, feeders, and urban plantings have 
probably helped such non-migratory species extend northward.  These factors
helped the Mockingbirds spread northward too, although feeders probably
are not as important.

Feeders are almost certainly responsible for the winter survival of Anna's
Hummingbird, which now is easily found in Vancouver BC through the winter.
Probably a few members of of t`is non-migratory species always dispersed
northward, but never survived north of California until feeders were kept
up all winter.

One of the most spectaculcr bird range expansions in recent years (except
for the introduced Starling in North America) was the spread of the
Collared Dove across Europe.  Well, the species is now well-established
in Florida (escapes, or trans-Atlantic dispersal?), and they should be
appearing at *YOUR* feeder before long!

David Mark
dmark@cs.buffalo.edu