Likely there is a lot of ad hoc (or studied) information about
Currawong/Collared Sparrowhawk interactions that Stephen has access to that
is summarised into that sentence. Just as Pied Currawongs and Australian
Ravens will fight for a long time about ownership of a nest tree (they do
most years in my back yard) maybe these two do too. It would hardly be
surprising. Currawongs have a bit of an advantage by virtue of being a pack
animal and small flocks of them can attack raptors. I and no doubt others
have seen and reported on that Currawongs will quickly harass a Sparrowhawk
that has caught prey. I saw that recently at my home when a Sparrowhawk had
caught a Crested Pigeon. Sometimes maybe intending to steal it or just out
of aggression.
The great increase in summer time (i.e. when they breed) abundance of the
Pied Currawong over nearly 30 years in Canberra of GBS data (as shown in my
book for 21 years but has continued) has not been matched by a decrease in
Collared Sparrowhawks. That is not to say that there is not a negative
impact happening.
Philip
-----Original Message-----From:
On Behalf Of Andrew
Thelander
Sent: Sunday, 1 December 2013 10:42 AM To: birding-aus Aus Subject:
[Birding-Aus] Collared Sparrowhawks & Pied currawongs
Hi all
I see in The Birds of Prey of Australia: A Field Guide by Stephen Debus
(OUPA, 1998) page 90, he refers to the population explosion of Pied
Currawongs in SE Australia as a potential threat to the Collared
Sparrowhawk. Currawongs are "a predator and competitor capable of robbing
and injuring adults and killing nestlings." Stephen is an authority in this
field and has a wealth of information. Currawongs have invaded Brisbane over
the years and are nesting in the city. I have also recently found a Collared
Sparrowhawk nest which has just been abandoned by the birds for reasons
unknown.
Does anybody have any information about Currawong/raptor interactions? It
seems the currawongs are here to stay in Brisbane.
Regards
Andrew
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