When people think of birds, they immediately think of beautiful elves flying in the sky. Indeed, in the history of biological evolution, the evolutionary trend of birds is that the body gradually becomes smaller, more flexible, and more and more suitable for rapid flight in the air, so that it can adapt to the changing environmental conditions by active migration. However, there are also some birds that have evolved in the opposite direction. Their bodies are significantly enlarged, their wings degenerate to become small, and their feet become large and powerful, they can only walk and cannot fly, and they are especially adapted to living on the ground, so they are called walking birds. These birds are small in species and numbers, and they are not the mainstream of bird evolution, but their lives are different, unique and fascinating.
Most of the birds are taller, but evolutionarily inferior birds with a range of primitive features in their body structure. Their wings have degenerated, the sternum does not have a keel protrusion, does not have a tail bone and tail fat glands, the feathers are evenly distributed without feather area and naked area, and there is no feather hook on the feather branch, so it cannot form a feather, which is soft and fluffy. The hind feet are thick and partially bare, and the toes tend to decrease as they adapt to running life, generally 2 to 3 toes. Male birds have well-developed mating organs.
The distribution of living walking birds is limited to Africa, South America and Oceania in the southern hemisphere. The main species are the African ostrich, the American ostrich, the crane ostrich, the emu, the kiwi and so on.
African Ostrich<h1>: The largest living bird</h1>
There is only one species of walking bird in Africa, the African ostrich. The African ostrich is a representative species of walking birds, it is the largest living bird in the world, with a body length of about 183 to 300 cm, a height of 240 to 280 cm, a weight of 130 to 150 kg, and a slightly smaller female. It has a peculiar appearance, with a slender snake-like neck supporting a small head. On the torso was a pair of short wings that appeared to be very disproportionate to the body, which had degenerated, had no feathers, could not fly, but were not completely useless. During the breeding period, males must show off their wings when courting the female, and adult birds during the incubation and brooding periods should spread their wings so that the eggs or chicks will not be exposed to the hot sun, and they can also open their own momentum to scare the enemies who dare to attack, in addition to spreading their wings when running quickly to maintain the balance of the body, if the wind can also play the role of sail.
African ostrich inhabit deserts, grasslands and shrublands and other areas, because there are developed air bags and good circulation system to regulate body temperature, so it can adapt to arid climates, has abnormal heat tolerance, even if the temperature is up to 56 ° C do not mind, still can find food in the hot sun, can also go for months without drinking water. Legend has it that when it encountered enemies, it buried its head in the sand while its body remained outside, thinking that if it could not see anything, it would be safe, hence the term "ostrich policy". In fact, this is a complete misunderstanding, because this phenomenon is only that African ostriches use sand to "clean" the parasites on their feathers, and the head is not completely buried in the sand, just laying its neck flat on the sand, otherwise it will die. In addition, if the weather is very hot, when the hot air rising from the ground meets the cold air in the air, it will cause the sunlight to scatter at the junction of the two airs, and if you stare at the places where these flashes of light, you can't see what is behind them.
The African ostrich adopts a crouching posture, lowering its tall body, laying its neck flat, hiding its head in the ground or under its wings, using the cover of flashing mist-like gas to make it difficult for other animals to detect its presence, so that it can avoid running in the hot and dry desert for a long time, which is both labor-saving and safe, so it is a rather clever way to avoid enemies and protect the nest and eggs.
There are two species of walking birds in South America, namely the American ostrich and the small American ostrich. There are also more than 40 species of birds in South America, which are customarily classified as walking birds, but in fact, they already have very developed flight muscles and certain flight capabilities.
The American ostrich is the largest bird on the American continent, its morphology is very similar to the African ostrich, with a small head, slender neck, curved back ridge, its nameless wings and long legs, but the body shape is slightly smaller than the African ostrich and appears slender, the body length is 80 to 132 cm, the height is 120 to 170 cm, the weight is 25 to 36 kg, and the female is slightly smaller. Unlike the African ostrich, the American ostrich has very similar plumage , except that the male is slightly darker , and the feathers are not as long as the African ostrich.
Oceania: A paradise for walking birds
Oceania is the continent with the most bird species, including emus, crane ostrich, kiwi and so on. Emus is only distributed in Australia, so it is also called the Australian ostrich. On Australia's coat of arms, on the left is an upright kangaroo and on the right is an emu with a long neck.
The emu is larger, with a body length of 139 to 190 cm, a height of 180 cm, and a weight of 50 to 60 kg, making it the third largest living bird in the world. Emus live in open grasslands in evacuated jungle and semi-desert areas, mainly eating wild fruits, leaves, weeds and other plants, but also pecking at insects. Because its call resembles "and miao, and miao...", it got its name emus.
At first glance, emus and ostrich seem to be similar, but in fact, they have many differences: one is that the size of the emus is smaller than that of the ostrich; the second is that the emus's neck feathers are dense and very plump, while the ostrich's neck feathers are very rare and almost bald; the third is that the emus has three toes on its feet, and the ostrich has only two toes.
Although the emu cannot fly, it has strong legs, is very good at running, and has good endurance. Some people have measured that the speed of emus is faster than that of ostriches, reaching a speed of 48 to 60 kilometers per hour, and the fastest can run 80 to 100 kilometers per hour, so it is praised as a "high-speed runner". What is even more peculiar is that in case of emergency, the emus can also chop the waves, swim freely, and make it escape.
Another group of walking birds in Oceania is the crane-camel, with three species, namely the crane-camel, the single-weeping crane-camel and the pygmy crane-camel, which are mainly distributed in northern Australia and New Guinea and some nearby islands.
The ostrich is also similar in shape to an ostrich, but smaller than an ostrich, with a body length of 130 to 160 cm, a height of about 180 cm, and a weight of 50 to 80 kg, making it the second largest bird in the world. The wings of the crane ostrich have degenerated, but the legs are strong and powerful, with 3 toes on the feet, and long claws at the ends of the toes, which are good at running.
Although the crane ostrich resembles an ostrich, it has its own characteristics and is easy to distinguish from ostriches and other birds that can only walk and cannot fly. Its body feathers are mainly black, the head is bare, and it has a large, flattened black-green crown, also known as the bone crown horn, like a helmet to protect the head. The crane ostrich's long neck is mostly bare, pale blue, with 2 pieces of bright red flesh hanging under the throat. Its body has black mane-like feathers, and a wire-like hard plume densely inserted above its degenerated wings. Because of the legend that the crane ostrich can swallow charcoal, it is also named "cassowarman".
<h1>Kiwi: A strange wingless bird</h1>
In Oceania, in addition to Australia, New Zealand also has a bird distribution, and it is very unique, that is, the famous kiwi, there are three kinds: brown kiwi, large spot a few dimensions and small spot several dimensions.
If brown kiwi is the most peculiar bird in the world, it may not be too much, because the birds in everyone's mind have beautiful wings and can fly in the sky, even those birds that can't fly, such as ostriches, emuses, etc., also have wings. However, the brown kiwi has almost no wings at all, and only a trace of wing bones remains, so it is also called a wingless bird. Of course, it is impossible to fly.
The body length of the several dimensions is about 35 cm and the weight is 2200 grams. It looks like a large furry leather ball. Because there is no hard silhouette feathers that ordinary birds have, they grow fluffy willow-leaf-like feathers, which are soft and beautiful, and are as soft as silk.
Kiwi looks different from the several walking birds introduced earlier. Their necks are not long, their heads appear small, their eyes are smaller, their ear holes are relatively large, and they have hard whiskers on their faces. The pale yellow beak is pointed and slender, about 15 cm long, almost half the body length, like a thin cylinder, and curved downwards, similar to the mouth shape of the sandpiper mentioned in the Chinese idiom "clams compete, fishermen deli", so the brown dimension is sometimes called "sandpiper". What's even more interesting is that their nostrils grow at the tip of the beak, which is also unique among birds.
Kiwi inhabits dense forests and bushes and is a gregarious animal. Lurk in tree root caves or caverns during the day and come out at night to forage for food. It is good at running, digging with its claws, or pecking east and west with its long beak, pecking at earthworms, insects and mollusks from the dirt and rotten branches on the ground, and also likes to eat lizards and mice, and also eats some plants, such as berries and leaves that fall on the ground. They eat a lot of food, eating dozens of earthworms at a time, and can swallow 500 to 600 worms a day. Local legend has it that Kiwi also has many unique skills, such as being able to drag rabbits out of tree holes and even fishing in shallow shoals along the coast.
Why is it that only New Zealand lives in the world? Originally, in the late Cretaceous Period, 65 million years ago, New Zealand was once connected to Australia and Antarctica, and later, the Australian land mass split with the Antarctic continent and drifted north to its current position, and New Zealand also drifted away from the Australian continent. At that time, mammals did not appear on the earth, or they did not appear and were not widely distributed. Later, higher animals that appeared on other continents, especially those wild ferocious predators, could not enter New Zealand due to the barrier of the ocean, so Kiwi and some other primitive animals, such as wedge-toothed lizards, slippery-toed frogs, etc., could survive safely. Coupled with the warm climate and abundant food there, it has become a "nest" for these ancient types of animals.
Among the Maori people, an indigenous people of New Zealand, there is a saying that long ago, kiwi feathers were very beautiful and they could fly. But one day, there was a fire in the forest, and the birds and beasts in the forest quickly fled the fire, but Kiwi finally escaped from the forest, and as a result, the feathers on his body were scorched and became the dark brown color that he is now, and the tail and wings were also burned off, so he could not fly. This kind of legend may be the Maori borrowing material lyricism to lament the persecution of Western colonizers. Because before the arrival of European immigrants, New Zealand's kiwi were crowded and seen everywhere. Later, due to the large number of colonists hunting, many animals that competed with Kiwi for food and even harmed Kiwi brought in, resulting in a sharp decrease in the number of kiwi and endangerment.
Now, Kiwi, as a rare bird endemic to New Zealand, has been strictly protected by the government and has been selected as the country's "national bird". New Zealanders love Kiwi so much that they even like to be called "Kiwi". Now, Kiwi has become a symbol of New Zealand, and "Kiwi" has become another name for New Zealanders. On coins, national emblems, and stamps, there are several dimensions of the pattern, and even the brand numbers of the shops, many of which are named "kiwi".
Due to The Waywich's appearance and lifestyle habits, his reputation in the world is also getting louder and louder. Tourists from all over the world often come here to see them for themselves. However, Several Dimensions are all day and night, which often disappoints tourists. To solve this problem, the New Zealand government has established a special ecological park for visitors to enjoy Kiwi during the day in the famous tourist area of Rotorua, Rainbow Schönbrunn Park. There is a poultry hall that simulates the night view in the ecological garden, people walk into the poultry hall, it is as if they have entered a dark night, the sky is flashing with light moons and stars, if it is bright and dark, after the visual adaptation, you can see the old trees on both sides of the dead vines, rotten leaves, cute few dimensions of hidden from time to time...