Breeding behavior of captive Emperor Penguins (Aptenodytes forsteri) was observed at Sea World, San Diego, California during July, August, and September 1980, and April 1981. Emphasis was on displays, courtship, egg-laying, incubation, and care of chicks. I observed the trumpet display most often between birds of opposite sexes and I interpret it as a signal of sexual identity. I interpreted the sideways stare display as a signal of sexual identity important in pair bond maintenance. Three head movements studied shared several functions including comfort behavior and reduction of intraspecific aggression. My observations confirmed that the display walk occurs in Emperors and is used by males to attract females. The single note cry allows separated members of a pair to find each other. Results of an attempt to sex Emperor Penguins by vocalization are reported.