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Description
Length: 61
-66 cm (24 - 26 in). Weight: 816 g (1.8 lb - male) Chicken-sized
bird, with large wings, small head, long neck, long tail. Head
almost bare, with frizzy red crest, large bright blue area around
eyes, which are red. Short bill. Bronze olive color above, buff
streaks on hindneck and mantle; tail black, shoulders and tip
of tail pale buff; throat and breast buffy white; remaining underparts
and primaries, chestnut colored. Sexes similar but female slightly
smaller and has lower crest. "Prehistoric" appearance.
Range
South
American only; Guianas and Venezuela south to Bolivia, Peru and
Amazonian Brazil. Lowland, to 500 m altitude.
Habitat
Found in vicinity
of swamps, mangroves, lowland flood forest, river banks, oxbow
lakes, where aquatic vegetation and giant arums plentiful. Perch
on low or middle branches of vegetation overhanging water; occasionally
found in treetops, especially when roosting.
Niche
Feed primarily
on leaves and shoots of some marsh and swamp plants, mainly arums
(philodendron family). Leaves are ground in the large double crop,
and ferment there, giving bird a musky odor. Weak fliers because
of size of crop, which displace some of breast flight muscles;
thus they are sedentary and somewhat ungainly. Live in pairs in
groups of 50 or more. Perch on branches, while resting a callous
on sternum on branch. When alarmed, open large wings, displaying
bright chestnut flight feathers around a large black spot surrounded
by white - this simulates an "eye". Diurnal and nocturnal, tends
to rest during hottest part of day. Not palatable to humans but
preyed on by monkeys. Some evidence of relationship to cuckoos.
Life History
Breeds during
rainy season. During breeding, live in small groups of two to
ten; a few of which are breeders and the others, "helpers". Entire
group incubates eggs and cares for young, which are fed from crop
of adult caretakers. Mating probably polygamous and promiscuous.
Build loose stick platform two to eight meters above water. Each
nest contains two (occasionally three) creamy oblong eggs spotted
with pink, blue or brown. Incubation about 28 days. Newly-hatched
hoatzins almost featherless, but rapidly grow down, and have claws
on first and second digits, so they can climb on vegetation. When
endangered, they drop into the water, using claws, bills and feet
to climb out (they may not return to nest). Claws disappear at
time of definitive plumage formation. Remain in nest for several
weeks after hatching.
Status
Locally
common, but not near human habitation because of human predation
on eggs, and on adults for meat for bait, feathers for fans.
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