Gooday Bill and birding-ausser's,
I believe the Black Kite, Milvus migrans is supposed to be the
commonest bird of prey in the World, recall reading that somewhere?
While living in the Cairns area I was always amazed at how
quick a large gathering of these raptors would start to circle a cane paddock
during its burning off prior to harvest. As soon as the smoke rose the birds
seemed to come in from all directions I recorded 70+ on one occasion.
I have never observed them hunt live prey but believe the
macropod massacre that occurs regularly on many Qld. roads is more than
sufficient to meet the species food requirements.
I would consider the smoke of a fire to be sufficient evidence
of a possible food source for the bird to investigate. Apart from this the
highways, roads and rail tracks that criss cross our continent could
certainly provide good visual guides for a raptor to follow in search of
Only my thoughts of the top of my head.