Little Blue Heron

The Little Blue Heron is a small, slender heron with adult plumage of deep slate-blue overall, with a maroon-purple wash on the head and neck, and a bicolored bill that is pale blue-grey with a black tip. Uniquely among herons, juveniles are entirely white, closely resembling small egrets, and only gradually acquire blue feathers in a blotchy, piebald pattern during their first year before becoming fully blue as adults.

This white juvenile plumage is thought to help young birds mix safely with flocks of Snowy Egrets, reducing aggression from adults of other species and possibly improving foraging success.

Key field marks

• Adults: deep slate-blue body with a maroon head and neck, greenish legs, and a bicolored bill (pale base, black tip)
• Juveniles: entirely white with greenish-yellow legs and a pale bill, easily confused with egrets
• Transitional birds: patchy blue-and-white "calico" plumage
• Slow, deliberate walking gait while foraging

Similar species

• Snowy Egret: white juvenile Little Blue Herons resemble Snowy Egrets, but Snowy Egrets have black legs with bright yellow feet, while young Little Blue Herons have dull greenish legs
• Tricolored Heron: adult has a white belly, unlike the uniformly dark underparts of the Little Blue Heron

Leg and foot color is the best way to separate a white juvenile Little Blue Heron from a similar-looking Snowy Egret.

Range and habitat

Little Blue Herons are found across the southeastern and south-central United States, Mexico, Central America, the Caribbean, and much of South America, inhabiting freshwater marshes, swamps, mangroves, and shallow coastal wetlands.

Migration

Northern populations in the United States migrate south for winter, while populations in tropical and subtropical parts of the range are generally resident; post-breeding dispersal, especially by young white-plumaged birds, can carry individuals well north of the usual breeding range.

Behavior

Little Blue Herons forage slowly and deliberately, walking gradually through shallow water and pausing to strike at prey, in contrast to the more active, dashing feeding style of egrets like the Snowy Egret.

Voice

Calls include low croaks and harsh squawks, typically given during interactions at breeding colonies or when disturbed.

Feeding

They eat a varied diet of small fish, aquatic insects, crustaceans, and amphibians, hunted with slow stalking rather than the active running and wing-flicking used by some other small herons.

Nesting and breeding

Little Blue Herons nest colonially, often alongside other wading bird species, building stick platform nests in trees or shrubs near water; both parents share incubation of typically three to five pale blue eggs.