The white-tailed Kite was rendered almost extinct in California in the 1930s and 1940s due to shooting and egg-collecting, but they are now common again.
White-tailed kites feed principally on rodents; voles and field mice. They are seen patrolling or hovering over the open grassland and among the olive trees where they catch the voles that chew the olive tree base bark. This is very important at SRV because the voles are capable of girding full grown olive trees and killing them.

"The kites will feed on you, here on this field." Homer Iliad bk 16