Serge:
>It is the case of Bonelli's Eagle (?) _Hieraaetus fasciatus_ around
>the Mediterranean which tandem hunts rabbits and ground birds (e.g.
>partridges) in the `maquis' (a kind of chaparral I guess).

I don't know, but do know this has been most heavily studied in
Harris' Hawks, where extended family groups cooperatively hunt
and in addition use the result to feed the kids of a single
pair (turns out to be typically a sister of mom helping out).

An aquaintence of mine did his PhD on this topic, or more precisely
quantifyng the relationship between indirectly pushing your genes into
the future vs. doing so directly (by raising your own kids). As in
"under what conditions are the benefits of raising my own family
outweighed by helping my sister". And using the quantification to
predict where Harris' Hawks will most frequently do this (it's not
uniform across their range).

Fascinating stuff.

>There are also all these stories on sea eagles _Haliaeetus sp._ and/or
>Ospreys _Pandion haliaetus_ catching too big a fish and being unable
>to free their talons...

And kestrels taking pigeons in banding stations!

Hmmm...in my experience, most big raptors have halitosis, does
Haliaeetus?

- Don Baccus, Portland OR <donb at rational.com>