The situation is that if two (or more) species are capable of hybridisation, it is because they formerly were one species and have diverged, usually by geographic
separation, for a long time, into two different populations and then come to be sufficiently different in appearance to be regarded by us as being different species. That is where we are at with these corella forms. However the process of forming reproductive
isolation is not totally complete (or completely total). Then some factor comes into account, such as humans moving them around or rearranging ecological barriers, and they find themselves together again and can interbreed. The extent to which this happens
can be a whole spectrum of extents and that influences whether we call them species.
As for dogs. Not really. Dogs are dogs. All one species. In spite of the huge variations of breeds that we have created and given different identifiable names.
Philip
From: Canberrabirds [
On Behalf Of Martin Butterfield via Canberrabirds
Sent: Tuesday, 9 January, 2024 5:45 PM
To: Meke Kamps
Cc:
Subject: Re: [Canberrabirds] FW: FW: FW: eBirders! Take care with Long-billedCorella identification
A good question. Another good question is whether there is a point at which it is recognised that two (or more) species hybridise so frequently that it should recognised that they are in fact not species at all? The current fashion seems
to be only to split, never lump.
On Tue, 9 Jan 2024 at 17:23, Meke Kamps <> wrote:
Maybe a dumb question, but is there ever a point where a hybrid bird stops being a hybrid and is recognised as its own species (as happens with dogs) - or will these always be seen as hybrid birds?
On 9 Jan 2024, at 3:42 pm, Lindsay & Diana <> wrote:
Maybe the hybridisation started here
On 9/01/2024 2:37 pm, Geoffrey Dabb wrote:
Yes, and a couple of LBC xs were there in late 1980s along with little Corellas
From: Mark Clayton
Sent: Tuesday, January 9, 2024 1:47 PM
To: Geoffrey Dabb ; Canberrabirds
Subject: RE: [Canberrabirds] FW: FW: eBirders! Take care with Long-billedCorella identification
Isn’t that location the site of the old zoo?? I had always been of the opinion that the Long-billed Corellas locally originated from being released there when
the zoo closed down. Personally I don’t believe that they got here naturally unlike the Little Corella.
Mark
Sent from
Mail for Windows
From:
Sent: Tuesday, 9 January 2024 1:09 PM
To:
Subject: [Canberrabirds] FW: FW: eBirders! Take care with Long-billedCorella identification
Sorry, my error, careless map interpretation – ‘according to Birdata, the Callum Brae site is the prime spot for LBCs in the Canberra area’.
From: Canberrabirds <>
On Behalf Of Geoffrey Dabb
Sent: Tuesday, January 9, 2024 11:45 AM
To: Canberrabirds <>
Subject: [Canberrabirds] FW: eBirders! Take care with Long-billed Corella identification
Thanks Christine. Here are some further considerations. Before eBird, there was a small population of hybrids in the Canberra area, perhaps of aviary origin. It is not known
whether there were also any ‘pure’ LBCs. The hybrids came to be recorded as Long-bills, in the COG annual bird reports and in Birdata for example. No doubt many observers included them as such in personal records. The introduction in eBird of the ‘hybrid’
option created a third category, requiring a decision whether a particular record was of a hybrid or a pure LBC. While some specimens we see today seem indistinguishable from a pure LBC, it is difficult to be certain going by visual evidence alone. It is
a matter for the observer and reviewer to arrive at the appropriate category for eBird purposes. The category for other purposes is a different issue.
To supplement this note I’ve prepared the attached graphic. According to Birdata, the Bowen Park site is the prime spot for LBCs in the Canberra area. Incidentally, I am cautious
about making use of field guides on this issue, because (unless photos) the illustrations are usually diagrammatic, unlike the ones in Forshaw & Cooper editions, which show particular identified specimens.
From: Canberrabirds <>
On Behalf Of Christine via Canberrabirds
Sent: Monday, January 8, 2024 8:28 PM
Cc: Canberra birds <>
Subject: Re: [Canberrabirds] eBirders! Take care with Long-billed Corella identification
Hi all,
second try as my photos made my email over the limit.
It is indeed a tricky one, as by some definitions I would think there has never been a Long-billed Corella in the ACT, but by the definition and illustrations in many Field Guides
there are, by now, quite a few.
For your interest, here are a couple of photos I took today at Lake Ginninderra.
Quite apart from the Little Corellas in a nearby tree were five individuals together in a seperate tree, each with plenty of pink/red, and it appeared to be a family group. Three
together on one branch, the two on the outside were begging, and the one in the centre fed them (first photo). Just above them two more individuals with the same colouring (second photo).
ps It was raining, so even worse than usual photos.
<Long-billed (perhaps) & Little Corellas Lyneham 4.8.2012.jpg>
--
This is the email announcement and discussion list of the Canberra Ornithologists Group.
Emails posted to the list that exceed 2 MB (2,000 kB) in size, including attachments, will be rejected.
All emails distributed via the list are archived at
http://bioacoustics.cse.unsw.edu.au/archives/html/canberrabirds. It is a condition of list membership that you agree to your contributions being archived.
Canberrabirds mailing list
https://lists.canberrabirds.org.au/mailman/listinfo/canberrabirds
|
ATT00001.txt
Description: ATT00001.txt
|
