Egg patterns as identity signals in colonial seabirds: a comparison of four alcid species.

The ability to recognize mates, kin, offspring and neighbors by their individually distinctive traits-individual recognition (IR)-is widespread in animals. Much work has investigated IR from the perspective of the recognizer, but less is known about the extent to which signals have evolved to facilitate IR. To explore this, one approach is to compare putative identity signals among species that differ in life history and extent of IR.