Wild Birds

An insight on some of the most popular wild birds

When we think of birds, we usually think of creatures that fly and sing. Yet some birds cannot fly, and most of these wild birds do not sing. They usually hiss, snort, roar, boom, whistle, or grunt.

Of course, most birds can fly. They depend on flying to get food, to travel, and to flee when they sense danger. But some kinds of birds—a few dozen—are flightless. Some, like penguins and ostriches, have very heavy bodies with wings that are too small to support their weight in the air. A few parrots, ducks, and other birds in families of normally powerful fliers are also flightless.

Scientists believe that all the wild birds living today are descended from birds that could fly. The reason for this belief is that the wing bones of wild and flightless birds have the same structure as those of flying birds. But the wings of these birds are no longer used for flight.

The best known group of wild birds is made up of kiwis, cassowaries, emus, rheas and ostriches. All live in the Southern Hemisphere. They are known as ratites, from the Latin word for raft (a boat without a keel). Ratites have a flat breastbone without the keel-like structure to which flight muscles are attached in flying birds

Here is an insight on some of the most popular wild birds

Ostriches
The ostrich is the largest living bird. It may be as much as 2.5 meters (8 feet) tall and weigh about 135 kilograms (300 pounds). It has long, bare legs; only two toes on each foot (fewer than any other bird); and a long, pink, featherless neck. Males are black with white wing and tail feathers. Females are grayish brown. Both have thick eyelashes of fine feathers.

Today ostriches are found in the wild only in the grasslands and semi-desert areas of eastern and southern Africa. They usually live in groups of one male and three to five females. But sometimes as many as 40 to 50 birds may be found together. Ostriches eat grasses, leaves, and fruits, as well as insects and lizards. They also swallow large amounts of sand and small pebbles to help digest their food. Ostriches make a loud, hissing sound. In the breeding season, the male produces a booming roar. In east central Africa these huge birds often gather with herds of zebras, antelope, and giraffes.

During the breeding season, several female ostriches lay eggs in the nest made by a male. The eggs are huge and creamy white in color. Each female lays about six to eight eggs, usually one every three days. Unlike other ratites, male and female ostriches share the incubation. The male sits on the nest at night, and the females take turns by day.

Ostriches have one of the longest life spans of any land animal. Some ostriches, especially those raised in captivity, may live to be 70 years old.

Rheas
Rheas are found only in South America. They are sometimes called South American ostriches, or pampas ostriches. There are two kinds of rheas. The common rhea of Argentina and southern Brazil is about 1.5 meters (5 feet) tall. It may weigh more than 25 kilograms (55 pounds). The Darwin's rhea is somewhat smaller. It is found on the plains of western Argentina and high in the Andes mountains. Both the common rhea and the Darwin's rhea are brown in color. Unlike ostriches, rheas have feathers covering their heads and necks, as well as their bodies.

Rheas live in flocks of 20 or 30 and sometimes more. At times they mix with herds of deer or cattle. They eat leaves, roots, and seeds, as well as insects and lizards. When they run, rheas hold their necks stretched out in front of them. Often they make sudden twists and turns. Their calls are whistling noises and a deep booming sound.

The shells of rhea eggs change color. When they are laid, the eggs are green. During incubation they become yellow, then blue. Finally, when the chicks hatch, the eggs are white. As the newly hatched birds begin to search for food, they and their father whistle to keep in contact.

Rheas are no longer hunted for sport as much as in the past. But their numbers continue to decrease for another reason. Fences have been built to enclose cattle on ranches. These fences limit the areas where the rheas can find the food they need to survive.

Emus
The tallest ratite after the ostrich is the emu, which lives in Australia. It may be as much as 1.8 meters (6 feet) tall and weigh up to 55 kilograms (120 pounds). Its hairlike feathers are brown or blackish brown. Like ostriches and rheas, emus live in open country. They feed on a wide variety of fruits and other plant material. They also eat insects. Emus make hissing, grunting, and booming sounds, and the females lay eight to ten dark green eggs.

The emu is sometimes considered a pest because it knocks down fences and tramples crops. At one time, bounties (payments) were offered for shooting these birds. But today specially designed fences are used to keep the emus from entering the fields. Emus are raised in some countries for their meat and the oil obtained from their fat.

Cassowaries
Cassowaries live in thick forests. Their feathers are black and shaggy. The long, white quills that stick out from the ends of their wing feathers are thought to show that the wings were used for flight long ago. Their heads and necks are bare of feathers and are brightly colored. The top of a cassowary's head has a casque, or bony helmet. The casque is thought to protect the bird as it runs at great speed, head first, through dense forest. Cassowaries may be more than 1.5 meters (5 feet) tall and weigh about 55 kilograms (121 pounds). The female cassowary is larger than the male and lays between three and five pale green eggs.

The one-wattled cassowary and the Bennett's cassowary are found in New Guinea and on some of the nearby islands. The Australian cassowary lives in coastal forests in northeastern Australia. Cassowaries usually live singly or in pairs. They are active day and night, feeding mainly on berries and fruit. Their calls sound like snorting, grunting, and bellowing. Cassowaries are hunted for use as food. They are also valued for their feathers, which are used in headdresses. But these birds are difficult to hunt, and they can be very dangerous. Cassowaries will charge at people, feet first, often killing or badly wounding their victims with the long, sharp claws of their inner toes.

Kiwis
Kiwis are very small ratites. A kiwi is the size of a domestic hen and weighs between 1.5 and 4 kilograms (about 3 and 9 pounds). Kiwis are tailless and have short legs and short necks. This gives the body a rounded or hunched appearance. The tiny wings cannot be seen through the shaggy, brown feathers. A kiwi has a very sharp sense of smell, which most birds lack. Its bill is long, slender, and flexible. And unlike the bills of other birds, a kiwi's bill has the nostrils at the tip. Female kiwis are larger than males.

There are three kinds of kiwis—the common, or brown, kiwi; the great spotted, or large gray, kiwi; and the little spotted, or little gray, kiwi. All are found in New Zealand and on its offshore islands.

A kiwi egg is white. It is 180 millimeters (7 inches) long. This is an extremely large egg for the size of the bird.
Kiwis live in burrows in thick forests. They hide by day but come out at night to feed on earthworms and insects. Their calls are shrill whistles or screams.