“…In such colonial species, parents must memorize the identity of their young before they fledge. This ability is found in various colonial birds such as swallows (Hirundo rustica: Medvin and Beecher, 1986; and Tachycineta bicolor: Leonard et al, 1997), terns (Sterna bergii: Davies and Carrick, 1962), cockatoos (Cacatua roseicapilla: Rowley, 1980), penguins (Spheniscus demersus: Seddon and Vanheezik, 1993), gulls (Larus atricilla: Beer, 1970), murrelets (Ynthliboramphus antiquus: Jones et al, 1987) and Piñon jays (Gymnorhinus cyanocephalus: McArthur, 1982). Unlike in mammals, in which parent-offspring recognition relies on various combinations of visual (Ferreira et al, 2000), olfactory (Maletinska et al, 2002;Dobson and Jouventin, 2003;Phillips, 2003) and auditory (Illmann et al, 2002;Terrazas et al, 2003;Mathevon et al, 2004) cues, avian parents seem to recognize their offspring by their voices (Saino and Fasola, 1996;Jouventin and Aubin, 2002;Insley et al, 2003); no visual or olfactory cues are known to play a role in this recognition.…”