"These tortoise-killing ravens are so smart, scientists must use drones to stop them"

LAT:

Instantly, the quadcopter squirted streams of silicone oil into the unoccupied raven’s nest, thoroughly coating a clutch of simulated eggs.

While the attack may have lacked the shock and awe of a Hellfire missile strike, it would have proved lethal to actual raven eggs. The layering of oil would have prevented oxygen from permeating the shells, slowly suffocating the embryos within.

...

Other options now on the drawing board include “techno-tortoises”: realistic replicas of baby tortoises that, when pecked or bitten, emit irritants derived from grape juice concentrates