Introduction
Intertidal Life
Sea Turtles
Land Iguanas
Marine Iguanas
Sea Lions
Fur Seals
Birds
Herons
Flamingo
Residents
Migrants
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Herons and egrets are long-legged wading birds found over much
of the temperate world, and it's no surprise there are six species
of herons found in the Galápagos, five of whom are resident.
Several of these species are quite familiar to North Americans
-- the great blue heron and the great egret in particular. Usually
herons feed on small fish or crabs, hence their regular appearance
along rivers and coasts. But in the Galápagos, they also
prey upon lizards, small iguanas, young birds, and turtle hatchlings.
Though large birds, they are sometimes hard to spot: they will
stand motionless as a treelimb, patiently waiting for an unsuspecting
meal to wander within range of their long, darting neck.
Largest of the Galápagos herons is the Great blue heron
(Ardea herodias), often found in the mangrove forests
of the coastal zone. The local race is somewhat darker than the
North American blue heron -- to whom it is more closely related
than the white-necked variety found in South America. Blue herons
are strong if slow flyers, but are usually seen quietly waiting;
the Galápagos race is, like many other native inhabitants
of the archipelago, remarkably tolerant of human beings. They
are quite large, exceeding four feet in height with a wingspan
easily twice that. (James J. Audubon, the American ornithologist,
prided himself on painting all his subjects at life size; his
canvas of the Great blue heron shows the bird in an uncharacteristic
contorted posture -- head ducked, neck bent but extended, wings
akimbo -- but all to scale!)
The all white Great egret (Casmerodius alba) is
also found here, though probably as a migrant rather than nesting
species. These birds are sometimes mistaken for the Great blue,
which also has a white phase. Cattle egrets (Bubulcus
ibis) are also found, usually in the highlands with introduced
cattle herds. Though today a common sight, these smaller white
egrets are native to Africa, from which they migrated only in
the last century to their current world-wide distribution.
Unique to the Galápagos is the endemic Lava heron (Ardeola
sundevalli), frequently observed along the shores where it
feeds on small fish, crabs and lizards; like the other herons
it nests in mangroves. It is descended from, and perhaps only
a variety of, the Striated heron (Ardeola striata),
a slightly more distinctly marked bird with pale neck and breast
with a black cap; the lava heron is almost entirely slate gray,
ideal camouflage against the basaltic rocks of the islands. The
scientific jury is still out on whether these are distinct species,
or whether the more well-adapted lava heron is an evolutionary
descendant of the emigrant striated.
The sixth heron found here is the Yellow-crowned night heron
(Nyctanassa violacea), quite common along waterways throughout
the Americas. Mainly active at night, it feeds on insects large
and small, and is sometimes seen in Puerto Ayora catching bugs
by the light of streetlamps. Though primarily a coastal inhabitant,
it has been sighted high on the volcanic slopes of Isabela, where
it presumably forages for grasshoppers and other large insects.
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