I have a question for you. My children showed me a Koala in a
Eucalyptus tree at the local shops
being mobbed by Noisy Miners. What threat is the Koala ? He's ignoring
all the fuss and just dosing in his fork in the tree. Are Koalas nest
robbers and do they eat eat birds eggs and nestlings at night, ( I think
not ), or are the Miners carrying on like a pork chop just for the fun of
it ?
The local gardner has said that the Koala has been there for 2 days
and
the N Miners have been hounding it almost continually for that time. I do
not think there were any nests in the tree.
Any thoughts ?
Peter,
the Koala is highly unlikely to be a predator of birds or their eggs - its
gut is highly evolved to handle foliage, particularly eucalypt foliage
which is a very poor choice of food [it is tough, of poor nutritional
quality, contains many potentially toxic compounds and has little protein].
My guess is that the miners do not distinguish between mammal species and
treat them all as potential predators. Certainly the local Common Brushtail
Possums and probably Common Ringtail Possums are potential predators of
nest contents and roosting birds. The presence of a large, furred critter
in a tree may be more than adequate to elicit a mobbing response in Noisy
Miners, which as we all know have a low threshold for this anyway.
Peter Menkhorst
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