birding-aus
At 17:04 9/02/99 +1100, Philip A Veerman wrote:
>It seems that most places (or at least urban places) only support one common
>corvid species.
Sympatry in Australian corvids is quite intriguing given that they all seem
so similar in morphology, phylogeny and ecology. In urban, rural and bush
Townsville Aus Raven and Tor Crow are sympatric. Tor is more common but I
think Aus is fast catching up. Its hard to be sure if things are changing
or balanced. When I first lived in Townsville in '89 Aus. was around but
scarce, and now they seem common. It will be intersting to see if Tor
disappears in time. In recent years I've watched their interactions a few
times and they seem quite confrontational but not aggressive and outcomes
are hard to gauge. they're difficult to observe interacting because mostly
they fly far during the process, one species (usually Tor) following the
other (but at quite a distance). Tor are much more prone to flocking so
they seem to gang up on ravens in pairs.
Where else are there sympatric corvids.
David James
PO BOX 5225
Townsville Mail Centre 4810
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