I cannot add to data on Australian birds, but some might be interested in
similar observations from western Canada, particularly British Columbia. A few
years ago, some concern was expressed about a few species common in southern BC
- their numbers were declining. It was not until later that it was discovered
that there was a corresponding increase in their numbers further north. Their
numbers may not have been declining after all, just shifting northward. This
is all fairly recent, so there is not much in the way of hard data yet, just
birders' observations. As I recall Common Nighthawk was one of the first
species. There is one biologist/geographer in Vancouver doing some research on
this topic and I understand he does have some fairly convincing evidence of
range shifts, which he is linking to climate change. I don't know if he has
published anything yet, but I can make some enquiries. If anyone is interested
in further reading on
this topic in the northern hemisphere, contact me privately and I'll see what
I can find out.
Gary Davidson
--- On Wed, 1/27/10, James O'Connor <> wrote:
From: James O'Connor <>
Subject: climate change & bird distribution
To: "Greg Roberts" <>, ""
<>
Received: Wednesday, January 27, 2010, 9:34 PM
Hi Greg,
Thanks for this post: these are very interesting observations about potential
range shifts which, as you point out, haven't received a lot of attention. I
would be interested to hear from other observers of other potential range
shifts or contractions, especially latitudinal and altitudinal shifts. We're
particularly interested in the fragmentation of populations in eastern
Australia along the GDR, but all observations of this kind would be welcome as
a starting point.
We have used the Atlas to identify or confirm range shifts and contractions in
several species (e.g. Australasian Bittern and Crested Pigeon), but Greg's
observations are news to me, and I am sure there are other examples.
Cheers,
James
Website address: http://www.birdsaustralia.com.au
Atlas website: http://www.birdata.com.au
ABN: 87 004 076 475
Australian Partner of BirdLife International
-----Original Message-----
From:
On Behalf Of Greg Roberts
Sent: Wednesday, 27 January 2010 7:10 PM
To:
Subject: climate change & bird distribution
There has been a good deal of material about the southern extension of range
of more northerly species which may be due to climate change. Less has been
said in Australia at least about the converse - the possible shrinkage of
range of more southerly species.
South-east Queensland is the northern limit of range of quite a few
southerly species, so here would presumably be a good place to look.
I have found, going through my old notes, that Crimson Rosellas in southeast
Queensland were, in the 1970s, once widespread and common in places where
they are now scarce or absent - for instance, about Little Yabba and
Booloumba creeks in the Conondale Range. The species is still common in high
mountain, high rainfall sites such as the Border Ranges, but there is little
doubt in my view that it has declined sharply in numbers elsewhere in the
region.
In similar vein, I believe populations of Satin Bowerbirds have fallen,
especially at lower altitudes. South-east Queensland is the northern limit
of range of the south-east Australian populations of both Crimson Rosella
and Satin Bowerbird, though both species have disjunct populations in north
Queensland. I do not know if anything is happening with their populations up
there.
A third species, the Red-browed Treecreeper, does not occur north of
southeast Queensland. I believe its numbers have also dropped sharply in
this region. It was formerly a regular site, for instance, in the Blackall
and Conondale ranges, but it seems to be much more scarce there today.
Food for thought.
Greg Roberts
===============================
www.birding-aus.org
birding-aus.blogspot.com
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
===============================
==============================www.birding-aus.org
birding-aus.blogspot.com
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
==============================
__________________________________________________________________
The new Internet Explorer® 8 - Faster, safer, easier. Optimized for Yahoo!
Get it Now for Free! at http://downloads.yahoo.com/ca/internetexplorer/
==============================www.birding-aus.org
birding-aus.blogspot.com
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
=============================
|
