That�s right, BLM has EUTHANIZED 700-800 desert tortoises. Trust but verify. Click here to read one of many stories about it.
<*SIGH!*> There they go again....
Plainly this lady ain't had Ecology 101 either.
It ain't so much the individual tortoises ya gotta worry about, it the HABITAT. Preserve the habitat and you preserve the species. Without the habitat, all you'll ever have is a captive population.
A for the habitat angle re: the tortoise vs. grazing, browsing around I found only inconclusive studies on the impact of grazing on tortoises.
The problem seems to be there's so many OTHER factors that hammer tortoises its hard to isolate the effect of grazing.
One problem with grazing seems to be cattle stepping on and collapsing burrows, why that hould be lethal to an adept burrower like the tortoise I dunno. Another problem seems to be range degradation and introduced weed plants associated with overgrazing.
But again, unless I missed 'em, I didn't find any quantified studies.
Birdwatcher
