By Peter Travers
October 17, 1988 12:00 PM

>SIGOURNEY WEAVER (Gorillas in the Mist) As primatologist Dian Fossey, she protects the endangered mountain gorillas of Africa with a stunning, scary ferocity.

JEREMY IRONS (Dead Ringers) As twin gynecologists with kinky hangups about medicine, women and each other, Jeremy Irons is eerily convincing.

FOREST WHITAKER (Bird) As the late jazz sax genius, he rises from supporting actor to major star under the impassioned direction of Clint Eastwood.