On Monday Susan McDougall asked about cooperative hunting in Peregrine
Falcons and whether this technique is common in the species.

Yes, they do hunt cooperatively. Not only for food, but also as part of
pair-bond maintenance. How else can you explain the downtown Seattle pair
(Stewart and Bell) taking turns chasing a hummingbird one summer day morning
a few years ago?

Derek Ratcliffe in The Peregrine Falcon (1993 second printing, T & A D
Poyser Ltd, London), on page 148:

"when hunting in pairs, as they often do during courtship and when the young
have fledged, the falcon (female) and tiercel (male) can show remarkable
coordination in their combined efforts, and Treleaven describes how one bird
may steer the prey into the attack of the other."

Martin Muller, Seattle
MartinMuller at email.msn.com