Poor Flyer, Good Climber—The Unique Hoatzin
By “Awake!” correspondent in Suriname
‘THEY look like pheasants,’ suggested one scientist.
‘They strike me as fowls,’ claimed a colleague.
‘No, they are most nearly related to the cuckoos,’ challenged others, spurring the author of one reference book to write cautiously: “Placement in the zoological system debated.”
But just what are “they”? Well, they are neither pheasants, fowls, nor cuckoos. They are hoatzins. And so different are they from other birds that some ornithologists classify them in a family all to themselves.
If you’ve never heard of the hoatzin, though, this no doubt is due to the fact that they live only along the tropical rivers of South America. (The hoatzin fares poorly in captivity, according to one ornithologist I spoke to.) Nevertheless, some of its numerous nicknames may ring a bell. They range from colorful Cigana (Gypsy) to embarrassing Stinking Bird, and from eminent Governor van Batenburg’s Turkey to humbling Crazy Hannah. Completing the list of this bird’s aliases are Crest Fowl, Canje Pheasant, and the name the Amerindians gave it, Zezieras.
Early reports on this bird called it “the most peculiar of all birds inhabiting the South American forests.” Since about 650 different species of bird inhabit Suriname alone, perhaps this was somewhat of a hyperbole. Nevertheless, the passing of time and new findings have not altered man’s fascination for this remarkable creature. Why, during the last 25 years, scientists have often lowered their binoculars in old-fashioned puzzlement and exclaimed that hoatzin is “amazing,” “unique,” “completely different,” “strange,” “unusual,” and “most remarkable.” But just why does hoatzin merit these adjectives?
Crazy Hannah
To find out, I one day focused my binoculars on a small, jungle-thick island in the Courantyne River—the border river with Guyana and the only part of Suriname where the hoatzin can still be found. Since they are most active at dawn and dusk, our little party made sure that our small dugout canoe reached the island shortly after sunrise.
When we got to within 50 meters of the island, we knew we had found them.a Their loud call—like “chachalaca”—gave them away. When a group of about ten of them now appeared, we held our breath and tried not to move. The birds, however, scurried through the branches, doubling the volume of their strange call.
“You see, that’s why we call them Crazy Hannahs,” said David, our Amerindian friend. “A sane bird would keep quiet, hide, or take off. But these Hannahs make more noise and stay around! A bird like that must be crazy,” chuckled David.
Crazy or not, we were glad they gave us ample time to have a long, close-up look. The bird is about 60 centimeters long, roughly the size of a pheasant, with its big, round-tipped wings and long, broad tail accounting for most of its size. Its plumage is rich with autumn colors of chestnut brown, rusty red, and glossy olive-green streaked with black and buffy white. But higher up the colors change. A long, skinny neck supports a small head. Its crimson eyes are framed by a bare skin of cobalt blue.
What the head may lack in size is compensated for by its striking buff-colored crest. Crest Fowl indeed! With every slight move of its head or touch of a breeze, the crest plumes wave like a fan.
Food and Storage
As it turned out, the hoatzins were having breakfast when we interrupted them. They are vegetarians and feed on leaves, buds, pulpy seeds, and fruits. In fact, we spotted one high up enjoying the leaves of the corkwood tree. But their favorite food is the mokomoko, or arum—a native plant with giant, arrowhead-shaped leaves. The bird tears into the tough leaves with zest, gulping down big tatters to fill up its crop.
Crop? Yes, the crop is a pouch 50 times as big as the bird’s stomach. There the bird stores its food, where it soaks and undergoes preliminary digestion. This crop is so large that there is little room in the chest for strong muscles. The result? Hoatzin is a poor flyer.
Admittedly, when you hear the loud, whirring sound of this bird in flight, you imagine him to be the picture of grace. But not so. Oh, he tries hard enough—flailing his wings strenuously, going all out but hardly moving. Actually, he looks more like a helicopter taking off than a sleek airplane. During a short flight of about a hundred meters, he screeches protestingly with every tiring beat of his wings, eager to touch down as soon as possible. Unlike other birds that land daintily, a hoatzin’s landing is more like a crash. He heads straight for the trees or bushes, grasping awkwardly with his widespread feet at every random branch within reach. It is strictly a hit-or-miss affair. Sometimes he drops several feet before he finally grabs hold, uttering a squawk of relief.
Changing of the Guard
During the rainy season—breeding time in hoatzin country—I once had the opportunity to have a close look at one of their nests. There it was, hidden behind a curtain of mokomoko stalks, sitting some 3 meters above water level. It looked functional but not fancy: a simple platform, crudely constructed of twigs as thick as pencils. Measuring about 30 centimeters in diameter, it had no soft bedding. And it was such a loosely built affair that you could see the small eggs right through the bottom of the nest. Usually you’ll see two to five off-white eggs, freckled with brown and pinkish spots, in one of these nests. They take about 28 days to incubate. But the mother and father have found a way to fight the tedium. They take turns in brooding the eggs.
Early morning and late afternoon there is, according to writer Lear Grimmer, the “changing of the guard.” Says Grimmer: “The birds usually exchange brief but formal bows before they shift places.” And once in place, they are courageous defenders of their offspring. Mouse opossums, tree boas, birds of prey, and squirrel monkeys all have an appetite for the eggs—and the young ones themselves! But the intruders are greeted by the warning cries of the intrepid adult birds, poised for attack!
What a Baby!
If the adult hoatzin is unusual, baby hoatzin is even more singular. When hatched, out comes a naked chick armed with a strong beak and oversize feet. But puzzle for a moment at the well-developed claws, or “fingers,” at the bend of each wing, much like our thumb and forefinger. E. A. Brigham, who studied them a century ago, exclaimed: “From an egg laid by a bird with two feet and two wings comes an animal with four feet.”
Only a few hours old, the young ones look over the edge of the nest and crawl out. On all fours they scramble among the branches and vines, using their parrotlike jointed beak, big clawed feet, and powerful wing hooks. Good climbers, all right! But the “hands” also make effective “paddles.” Whenever danger lurks, the little one dives valiantly three or more meters into the river. The good climber is thus both a skillful diver and an excellent swimmer. The chick might paddle to the safety of tangled undergrowth. Then, to let the parents know where it is, it will give a distinctive “squeeownk,” convert its “paddles” into “hands” again, and claw its way up. The alarmed adult birds will now come to its aid, helping the terrified chick back to the nest.
Odor as a Lifesaver
“Fresh horse manure,” wrote one researcher.
“A cow shed,” added another.
“They have a . . . disagreeable musty smell,” acceded the experts. They had held their nose too close to the bird and aired their opinion in agreement: Stinking Bird! Just where did the smell come from?
“Its meat . . . smells awful,” wrote one.
“It is not the meat that is smelling but the contents of the crop,” differed another. What do the natives think?
“Nothing wrong with the meat. When I ate it, I asked for more!” laughed William, a seasoned hunter. “Just like turkey.”
“It is not the meat but the feathers that have the smell,” adds an older woman who has plucked some. But the majority turn up their nose and insist: “They stink!” And that deep conviction may well be the lifesaver for this otherwise vulnerable creature.
Hoatzin may have a foul odor and be a not-too-graceful flier, but, come to think of it, to survive in a world where many animals are heading for extinction is an accomplishment in itself. Perhaps Crazy Hannah is not so crazy after all.
[Footnotes]
a 1 meter = 3.28 feet.