Gygax was enamored of social darwinism so I think "red in tooth and claw" was always part of the original druid concept.

The Romans described the druid's religion as "bloody" -- one that involved lots of blood rites. Think of the wicker man or midsommer. And while the Romans accounts were propaganda there is some evidence that the allegations of cannibalism might have been true.

Given where this circle is? I'm guessing lots of fish and the occasional harpy egg.