Don,

I think I remember a thread about the research done on the relationship of
raptors and grazing on the Zumwalt Prairie in NW Ore. . I just finished Macy
Houle's popular account of the research in " The Prairie Keepers" which
indicated potentially positive impacts of limited rotational grazing.

The hypothesis was that limited grazing encouaged young plant growth which
provided food for secondary grazers, Pocket Gophers and Belding's Ground
Squirrels which in turn provide forage for Swainson's, Red-Tailed and
Ferruginous Hawks in relatively high concentrations.

One conclusion weas that if rangeland is managed in manner which puts the
health of the range equal to or higher than the maximun short term output of
livestock that there is the potentil for considerable wildlife benefit.

Mike Waller