The little blue heron (Egretta caerulea) is a small heron of the genus Egretta. It is a small, darkly colored heron with a two-toned bill. Juveniles are entirely white, bearing resemblance to the snowy egret. During the breeding season, adults develop different coloration on the head, legs, and feet. The population of E. caerulea is declining. Many possible reasons for this have been proposed. Exposure to heavy metals has been found to have detrimental effects on young.