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Hi All,
1/ Years ago, long before the GBS database was a
comprehensive unit, when the GBS Results first showed decline of the Starling
starting to become obvious, I wrote a note for Gang gang about asking people to
carefully record Starlings for the GBS. I found it hard to believe that the
decline was real, as at that time, they were at my place every day. I suspected
participants were being slack and disinterested in recording such
"uninteresting" birds. It is now clear that it is real and the decline has
continued. This is well covered in the GBS Report and it is nice to see that the
trends shown there are continuing. I now go many weeks between observing
Starlings at home. The decline in the House Sparrow is occurring around the
world, well at least in Europe, so Canberra is not an exception. I have had
correspondence with various others and seen publications attesting to that.
Interestingly I have had the following e-mail
discussion (today) with someone from the ZOOLOGICAL SOCIETY OF LONDON who wrote to
me this week about the GBS trends, in particular following up about the House
Sparrow and its avian predators around the world. Extracts follow:
Dear Philip
That is superb - you've certainly whetted my appetite to see the book!
I've just emailed our librarian declaring it to be an essential addition to the
collection, so hopefully she'll be in touch. The EGI library is in Oxford - not
too far away. There's probably also a copy in the British Museum Library at
Tring, as they're supposed to have "everything" on birds.
The items from the entries below that stand out for me
are:
[Collared Sparrowhawk] declined to a low in Year 11
(1991) and since then has had a dramatic increase. For the first 14 years [House Sparrow] was the second most
common species but it has since declined. Wherever I
look, there is an almost relentless inevitability about finding increases in the
local small Accipiter where House Sparrows decline, and conversely no change in
status of the Accipiter where they don't. Granted your Currawongs have also
increased, but I somehow can't see a generalized, opportunist predator as a more
likely culprit than a specialist like the Collared Sparrowhawk - esp. as you
tell us that it's probably the predator most at home in suburban
environments.
Chris Bell
Conservation Programmes
Zoological Society of London
Regent's Park
London NW1 4RY
ZOOLOGICAL SOCIETY OF LONDON
LIVING
CONSERVATION
to which I have responded:
"If there is a connection between small
Accipiter increase and House Sparrows
decline, then I can see causative only in that direction (i.e. House Sparrows
decline could hardly cause a small Accipiter increase). It is indeed an
interesting connection, it makes sense, and if it helps, you are welcome to
cite this study as a consistent result. I wouldn't claim it on the basis of
this study alone, but then I didn't know anyone had found such a
connection. I'm sure there are many other factors involved. The Collared
Sparrowhawk here takes a lot of Common Mynas and Common Starlings too.
There may be partitioning between the sexes as to who takes what, as the female
is much bigger than the male."
Philip
2/ As for Geoffrey's second point about
"When calling (the 'doodle-doo' or 'hollyhock' call) Peaceful Doves do not open
their bills, but they DO close their eyes." As good as the photos are, I wonder
if it is mainly closing of the nictitating membrane. Beyond that, I can
only respond with the rather puerile lyrics of an less than fully imaginative
song "Do you close your eyes when you're making love" and suggest there is a
precedent.
Philip
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