Meet the Hoatzin!
This beautiful, pheasant-sized bird is native to South America's Amazon and Orinoco deltas. Like many of the birds on our list, it's the only species of it's genus, which is part of why it's so evolutionarily distinct. They're herbivores, feeding mainly on leaves, fruits, and flowers, but because of the way they digest those plant parts, the birds wind up quite stinky. In fact, the Hoatzin is also known locally as the "Stinkbird" for their vaguely manure-like odor. For that reason, it isn't threatened by human poaching; it's sort of a last-resort meal. You'd have to be really, really hungry to try to capture one of these critters.
Why is it weird? There's
a very good reason it's such a foul smelling bird. The Hoatzin has a
digestive system unlike any other bird, and actually more like a cow.
They have a foregut that they use to break down the plants they eat
using bacterial fermentation. It's not a rumen, as ruminants like
cattle have; instead, evolution operated on part of their digestive
anatomy called the crop,
a feature common to birds, to make it function much like a cow's rumen.
As a result, the crop is so large that it displaces muscles that
otherwise would have been used for flight. Hoatzins can still fly, just
not all that well.
But wait, there's more.
The
Hoatzin has another feature unique among all the world's birds, and
it's one that makes it a strong contender to inspire the next SyFy horror flick: it's got two claws on each of its wings!
The
wing-claws let the chicks move about tree branches without falling into
the water below as soon as they hatch. It's an important feature to
avoid becoming the next meal of a Great Black Hawk. When a hawk attacks,
the mature Hoatzins fly about to distract the predator, while the
chicks hide under thicker cover. If spotted, the chicks do an avian
version of stop-drop-and-roll. They plunge into the water, swim away,
and use their claws to haul themselves back onto land, up the tree, and
into the nest. Because of its claws, some researchers have wondered if
the Hoatzin was a direct descendent of Archaeopteryx, which had
three claws on each wing. Others think the claws are a more recent
adaptation, having emerged as a result of the selective pressure caused
by predation. Either way, the Hoatzin may be the most badass bird
around. They're a good reminder that dinosaurs still live among us.
H/T to: https://gizmodo.com
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