(I tried to post this a few days ago, but it got filtered out. Russell has
confirmed all is now ok, so here goes again, with apologies if some of the
context has got lost in the meantime).
Some observations about Red-tailed Blacks and Glossies, with reference to
Cas asking about food, and Tim Murphy talking about the party they saw at
Gatton the other day.
Red-tails are always around somewhere in the Lockyer Valley, and I've
recorded them at Abberton in every month of the year except December - but
I've no doubt they're not far away. They cruise around in smallish parties,
mostly say 3 to 15, presumably on the look out for food sources. When they
find something they like, they'll usually return to it every day until it's
exhausted. Around here Melia azedarach seems to be a favourite staple in
late summer and autumn, and there are some mature trees which they can be
depended to return to every season. I've also seen them feeding in
eucalypts, but am sorry to say that I've never troubled to id the trees -
which I will try to correct in future.
Glossies are much less frequent, but turn up at Abberton mostly in the
winter months. Their food sources are much more abundant in the higher
forests around the rim of the valley. I have only ever seen them feeding in
Allocasuarinas - littoralis and torulosa. Again, there are some favoured big
roadside specimens that they will regularly spend weeks in when they're
fruiting.
Regarding the sighting at Gatton, Tim mentioned not seeing any red in the
tail, or any yellow spotting, pale bills, and also that they were not
Yellow-tailed Blacks.
Both male and female Glossies have red in the tail; the Red-tailed male has
red in the tail, orangey/yellow in the female.
Any female in the group would have either yellow-spotting or a yellow face
patch, depending on the species. But, if they were all males, they would
have all had red in the tail.
Glossies and male Red-tailed Blacks have a darkish bill, female Red-tailed a
paler bill. But there are so many variables when looking at a group of birds
in flight, that can be a very tough one to pin an id on.
None of this is intended as a critique on the observers, or what they saw,
just a way of saying that the answer is that the birds weren't close enough,
or the conditions weren't good enough, to show their id features. There is a
size differential between the two, and the Glossy is often quite brown about
the head, but both are tough from a distance. In these circumstances it
would have to come down to call, and no amount of descriptive text about
calls is ever going to be much help - it just takes exposure and familiarity
to get the differences clear in one's head, or a lot of regular study of the
tapes. But even that will fade if you're not out there and lucky enough to
encounter the birds fairly regularly. And you've then got to combine the
call with a good visual id to get it lodged in the brain!
I'm seeing Red-tailed Blacks around quite a bit at present, and we haven't
had Glossies at Abberton since last July. But god forbid that we should ever
give in to allowing ourselves to id birds on the basis of probability
theory!
Tim, you said the birders divided into two camps; from what you've said you
were able to see, I'd have probably have given in and started a third -
"Don't know, can't tell, better view required".
Bill Jolly
"Abberton",
Lockyer Valley, Queensland.
Visit our website at http://www.abberton.org
-----Original Message-----
From:
Behalf Of Cas and Lisa
(also Silvia, Max & Viveka) Liber
Sent: Saturday, 20 March 2004 1:07 PM
To:
Subject: red tailed blacks and Melia azedarach
Dear Bill,
great photos! I am interested as Red Tailed blacks were apparently recorded
a very long time ago from the Sydney area (anyone ever seen them in
Sydney?). I live in Sydney's inner west where there is a flock of
Yellow-tialed blacks that like the casuarinas that were planted in amenity
plantings about the place. I am in contact with my local councils' park
officer and was telling him to plant more black cocky friendly trees
(sheoaks....banksia integrifolia) but I couldn't think of any others.
What else do the red tails like up there and anyone else know of what trees
yellow tails like (apart from pines that is)
Cas
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