Mike:
> 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.

This goes back to the whole notion of the fact that grazing can be
of benefit in some cases, to some species, but that the cattlefolk
seem bent on bending such findings into an argument that all
cattle grazing is beneficial in all instances. This makes it
politically difficult to support "good" grazing regimes, as the
other side will seize upon that support to demand that they,
"the real conservationists", be allowed to run more cows because
if one cow in one field is a good idea, a few hundred thousand
spread across the landscape must be a gawdamned stroke of brilliance.

The key, though, is in the phrase "some cases, some species".

For instance, I think all would agree that the irrigated alfalfa
fields one finds in the Great Basin, with their vast populations
of Belding's Ground Squirrels, are beneficial to raptors. Densities
can reach pretty intense levels of prey and predator, both. Indeed,
I've viewed fields through spotting scopes which have yielded
Hitchcockian vistas of horders of ground squirrels running to
and fro, and in one case a prairie falcon landing in their midst
with a look on its face which I can only describe as bewilderment
("too many choices!"). Hate to sound anthropomorphic, so perhaps
there just weren't enough brain cells to process thousands of
ground squirrel images in parallel.

A couple of cautionary notes, though. First, if there were
enough water, would it be wise to modify the entire sage-steppe
to irrigated alfalfa? The rancher might well say "yes! and
it's even beneficial to wildlife!". I would say, (sniff), "What
about my lovely-sounding Sage Thrasher and funky Sage Grouse?".

Also, this beneficial relationship is one of chance and economics,
not intent. Such huge numbers of ground squirrels must munch
a measurable amount of forage. Ranchers don't get rid of them
because it isn't economical (I've asked!) and they don't run
horses in these particular fields so there is no risk to their stock
of broken legs, etc.

But, imagine that some genetic engineer comes forth with a modified
virus targeted to wipe out all Belding Ground Squirrels in the
universe, cheaply, by infecting a few dozen in strategic locations.
What would be the rancher's reaction? Many would say "yeah,
go for it, gawdamn pests!".

And, poof, there disappears the benefit for raptors.

These are complicated issues...

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