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LITTLE BLUE HERON  Egretta caerulea 51–61cm. Fairly small dark heron of

varied wetland habitats, from estuaries and mangroves to flooded fields,

lakeshores, rocky coasts; more often at isolated small ponds and ditches than

other egrets. Singles or small groups, often mixed with other wading birds.

Hunts mainly by waiting, slow stalking. Adult smaller and darker than Reddish

Egret, with blue-gray base to bill, yellow-green legs. At height of breeding, bill

base and lores flush blue, legs and feet blackish. Wholly white 1st-year Little

Blue easily passed off as Snowy Egret but slightly stockier, with bluish-gray face

and black-tipped bill, yellowish-green legs and feet, fine dark tips to outer

primaries. Piebald molting birds seen frequently for a few months in summer. SOUNDS: Much like Snowy

Egret, but often slightly raspier. STATUS: Fairly common Sep–Apr, mainly below 1500m; smaller numbers

in summer (mainly nonbr. imms.); breeds locally in nw. lowlands. (Americas.)

TRICOLORED HERON  Egretta tricolor 56–66cm. Handsome, ‘snake-necked’

heron of varied wetland habitats, from river mouths and mangroves to flooded

fields, coastal lagoons, lakeshores. Singles or small groups, often with other

wading birds. Hunts by waiting, often coiled and hunched low in shallow

water, and by active dashing. Distinctive, but perhaps better named ‘bicolored’

heron, with overall dark gray plumage and contrasting white belly; also note

long slender bill, yellowish face. At height of breeding, bill base and lores flush

violet-blue, legs and feet pinkish red. 1st-year has rusty head and neck sides, like

adult in 2nd year. SOUNDS: Relatively high, drawn-out, squawking aaáah, at

times in short series; also lower nasal calls. STATUS: Uncommon to fairly common Sep–Apr, mainly in

coastal lowlands but locally to 1500m; smaller numbers in summer (mainly nonbr. imms.); breeds locally

in nw. lowlands. (Americas.)

REDDISH EGRET  Egretta rufescens 66–77cm. Rather large, dimorphic

(white morph scarce) egret of coastal habitats from river mouths and lagoons

to salt ponds, beaches, mangroves. Hunts by dashing actively, often raising

wings; also by stalking and waiting. Note fairly large size, slender bill (with

pink base most of year on adult), dark legs. Dark morph adult has shaggy rusty

head and neck plumes; white morph wholly white (all ages; also see p. 78).

1st-year dark morph (representing most records in Costa Rica) dull slaty gray

overall with variable rusty tinge to neck, dark bill; cf. adult Little Blue Heron.

SOUNDS: Mostly quiet; rarely low moaning groans and grunts. STATUS: Rare

nonbr. migrant Sep–Apr, mainly on Pacific coast, a few imms. may oversummer. (N America to

Caribbean, winters to S America.)

GREAT BLUE HERON  Ardea herodias 102–127cm. The only very large dark

heron in Costa Rica, widespread in fresh and saltwater habitats, from beaches,

estuaries, and mangroves to lakeshores, flooded fields, roadside ponds and

ditches. Often in areas with other herons, egrets, storks, ibises. Hunts by

waiting and slow stalking. Flight heavy, with slow deep wingbeats, neck

retracted in a bulge like other herons but can be extended briefly after takeoff.

Adult has clean white crown, shaggy neck and back plumes, clean plumage.

1st-year has black crown, duskier plumage with pale edgings to upperparts;

2nd-year like dull adult, crown partially to mostly white. SOUNDS: Flight call a

loud, explosive rrEK! Other varied sounds include deep throaty croaks, often with raspy, ‘complaining’

quality. STATUS: Fairly common to uncommon nonbr. migrant Sep–Apr, mainly below 1500m, rarely

higher; small numbers of imms. oversummer locally. (N America to Mexico, winters to S America.)