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BLACK-CROWNED NIGHT HERON Nycticorax nycticorax 56–64cm.
Chunky, mainly nocturnal heron often seen during the day in varied fresh and
brackish wetland habitats, from lakes in town parks to mangroves. Hunts along
edges and in shallow water, waiting and stalking slowly for fish. Roosts mainly
in trees, often not deeply hidden, at times with or near Yellow-crowned Night
Herons. Rather compact in flight, with short foot projection past tail tip, cf.
longer-legged, more lightly built Yellow-crowned. Adult plumage distinctive.
Juv./1st-year from Yellow-crowned by shape, especially pointed bill, shorter
legs, coarser pale streaks on upperparts (vs. pale spots and fringes to feathers).
Cf. Boat-billed Heron. 2nd-year like duller, browner version of adult. At height of breeding, adult lores
become black, legs flush bright salmon-red. SOUNDS: Flight call a gruff barking worhk! or wahk, with
rising inflection. Other low guttural calls when nesting and disturbed. STATUS: Uncommon to fairly
common Sep–Apr on both slopes, locally to 1500m; more local in summer, breeding mainly in nw.
lowlands and Central Valley. (Worldwide except Australasia.)
YELLOW-CROWNED NIGHT HERON Nyctanassa violacea 51–59cm. Mainly
nocturnal but often seen during the day, in varied brackish and freshwater
habitats, especially mangroves, along rivers. Main food is crabs, and regularly
hunts away from water, as in coconut plantations and on open beaches. Roosts
mainly in trees, often not deeply hidden. More lightly built than Black-crowned
Night Heron with stouter blackish bill, longer neck, longer legs; in flight, feet
project well past tail tip. Adult distinctive. Cf. Juv./1st-year Black-crowned
(nestling Yellow-crowned has yellow at bill base, soon darkens). 2nd-year like
duller, browner version of adult. At height of breeding, adult lores become
black, legs flush bright salmon-red. SOUNDS: Flight call a slightly grating owhr or kyowh, higher and more
nasal than Black-crowned, typically with more downward inflection. Low guttural clucks when nesting
and disturbed. STATUS: Uncommon to fairly common on both slopes, especially nw. lowlands; more
widespread Sep–Apr when n. migrants present, rarely to 1400m. (Americas.)
*BOAT-BILLED HERON Cochlearius cochlearius 46–53cm. Distinctive noc
turnal heron of fresh and brackish marshes, lakeshores, coastal lagoons, slow-
moving rivers, mangroves; spends the day roosting, well hidden in trees; tends
to leave roost later than night herons. Hunts at night along shorelines and in
shallow water. Flight direct with slightly stiff wingbeats emphasizing the
upstroke, subtly distinct from steadier bowed wingbeats of night herons. Note
very broad bill with distensible pouch, big dark eyes. Slightly smaller and more
compact than Black-crowned Night Heron, with shorter toe projection in
flight; adult has contrasting black underwing coverts. Juv. lacks pale spots and
streaks of juv. night herons. SOUNDS: Usually silent in flight at dusk. At roost when disturbed, and when
nesting, utters varied clucks and chatters, often with chuckling cadence, such as kuh-kuh kuk-kuh ku-kah.
STATUS: Fairly common to uncommon in coastal lowlands on both slopes, locally inland to 800m.
(Mexico to S America.)