Distinguishing Characteristics

Medium-sized heron of delicate build (adult length 56–66 cm; wingspan 100 cm; mass about 370 g, with males slightly larger than females); entirely white plumage; long, slender black bill; bright yellow bare skin in lores; and long, comparatively slender, black legs, with bright yellow feet. Immatures and nonbreeding adults have duller greenish-yellow feet, this color extending up rear of tarsus to “knee” joint, and paler grayish base of lower mandible. Adults in breeding plumage develop long, delicate plumes forming wispy spray of feathers extending off breast, recurving off lower back (arising from lower scapulars), and forming short, shaggy crest off nape. At height of breeding—but not necessarily coinciding with acquisition of plumes—lores and feet become much richer in color, tending toward reddish and orangish, respectively. Sexes similar in appearance even during breeding season. (For detailed plumage descriptions, see Appearance.)

Similar species include immature Little Blue Heron (E. caerulea) and Little Egret (E. garzetta). Immature Little Blue Heron, which has overall white plumage, distinguished by grayish to blue-gray lores (never yellow), thicker and more blunt-tipped bill that is grayish with black or dusky tip (never all black), more or less uniformly dull greenish legs (never with contrasting yellowish feet), dusky tips to primaries (most individuals), and often a few dark feathers in white plumage. Little Egret (E. garzetta), an Old World species casually observed along the Atlantic coast and recent colonist to the West Indies (breeds on Barbados), closely resembles Snowy Egret but appears slightly larger and stockier, having slightly longer, thicker legs, neck, and bill with slightly more noticeable gular feathering; these differences are subtle, however, and size overlaps somewhat with Snowy Egret. Little Egret best identified by color of bare skin in lores, which is grayish or bluish-gray (rarely greenish-gray or dull yellow, becoming reddish, orange, or blue-pink at onset of breeding); legs typically all black on adult (only immatures may show dull yellow extending up rear of tarsus); in breeding plumage, 2 (rarely 3) long, lanceolate head plumes (lacks bushy hind-crest of Snowy Egret; beware, however, some individuals, possibly hybrids or unusual Snowy Egrets that have been observed in New England, exhibited a bushy crest and 2 longer wispy plumes). For more information on distinguishing these species see McLaren (1989) and Massiah (1997).

Other white herons with black legs and contrasting yellow feet that could be confused with Snowy Egret include Chinese Egret (E. eulophotes) and Western Reef-Heron (E. gularis), both only accidental in North America. Chinese Egret distinguished by orange-yellow bill, bright blue lores, and short, shaggy crest during the breeding season, and by yellowish to bluish green legs and dark bill with yellowish base to lower mandible at other times of the year (Hancock and Kushlan 1984, del Hoyo 1992). Western Reef-Heron is a dimorphic heron (dark and white morphs; rarely also mixed plumage appearing piebald) that is closer in shape to Little Blue Heron, having a thicker, heavier, somewhat blunt-tipped yellowish to brownish-yellow bill with rather noticeable deeper gular area under bill, stouter and shorter tarsi, and (during breeding season) 2 or 3 head plumes as in Little Egret (Harris et al. 1996); dark morph birds are slate gray with white chin and throat, and only dark morph has been observed in North America (Am. Ornithol. Union 1998).