Officials say Ripley, a Harris's Hawk, was chased off the Zoo grounds by native red tailed hawks.
He was last seen Saturday.
Harris's Hawks are chestnut in color and their dark tails that have white at the base and tip.
Ripley also has an identification band on his left leg.
If you believe you have spotted Ripley, do not try to catch him.
Instead, call the Zoo's 24-hour emergency hotline at (559) 286-7403.