In China, there is such a saying: "Chinese life is the tip, and the word recognition is half.". Taking advantage of this sentence, I would like to show you these four strange words "chi (chi) owl (xiao) 鸺 (xiu) 鹠 (liu)", you can see that the right half of each word is "bird".
Even if you can't read these words, you can also know that these four words refer to "birds", and the protagonists we are going to talk about today are in them, this bird is called "oil bird (chi) scientific name (Steatornis caripensis)", in addition to the above three, birds with these words generally refer to "owl birds", which is the owl.
Oil owls
The oily owls are birds of the nighthawk family of owls, with a fan-shaped tail and dark reddish-brown wings that are long and wide. Usually living in the rainforests of South America, they like to move at night like owls, unlike most owls who build their nests on trees, while oily owls often live in groups in burrows.
And most of the owls are carnivorous birds, often feeding on rodents, and sometimes eating small animals such as insects, birds, and fish.
The oil owls are vegan birds and usually feed on fruit. But don't think that the oily owl will grow very small, they are not small at all, and some even grow larger than carnivorous owls.
This is because although they only eat fruit, they are very picky eaters, and the favorite fruits are these three: avocados, oil palm fruits, and olives.
The commonality of these three fruits is that the oily plover grows very fat, and the material they use to make their nests is the semi-digested pulp of these kinds of spit out of their mouths.
<h1 class="pgc-h-arrow-right" data-track="40" > oily duck favored by Indians</h1>
The young of the oily duck are also "fat" like a meat ball with feathers, because when the adult oilbird gets food, they usually choose to feed their children first, they peel off the pulp and the seeds inside and feed it to their chicks.
The growth period of chicks is very slow, from birth to growth need their parents to feed personally for 120 days, but also need to reach 70% to 100% of the normal adult body weight to really grow up, the most important thing is that the chicks can not fly.
And this bird is strange, because during a certain period of growth in the oily owl chicks, they will be larger than adult birds, and the body contains more oil than adults.
As the saying goes, "wealth is not exposed", such a fat and flightless chick was quickly targeted by the Indians. So whenever the breeding season of the oily ducks came, the Indians would come to the cave where the oily birds lived in groups, hold a ceremony, set up a large cauldron, and burn the fire underneath.
Then use a long pole to destroy the nest made of oil owl, to catch the flightless chicks, put them all into a pot, and boil them into oil.
It is said that the oil made by the chicks of the oily owl is colorless and odorless, and even if it is stored for a long time, it will not deteriorate, and it can be used as a torch and can be eaten, so the locals call it "walking oil bag".
<h1 class="pgc-h-arrow-right" data-track="40" > the specific function of the oil owls</h1>
Although the oily plovers look fat and stupid, they are not lazy at all, and when there is no food around, they will expand their foraging range, which is sometimes as large as 100 kilometers.
However, this is not a superpower, if you want to talk about the real special function, you must first talk about its residence - "cave". Think about which flying animals live in caves?
That's right, bats have ultrasound so they can find directions in caves where they can't see their fingers, and judge the location of obstacles and food.
The oily duck also has this function, in 1799 when the German naturalist Alexander von Humphrey, came here to explore, when he walked into the place where the oily duck lived, he thought he had entered the cave of the bat, which was not only dark, but also often had a sharp cry, and he quickly left here.
Although he was curious about how the oily owl moved in the dark cave, he did not believe that it used ultrasonic waves to locate it like bats, because the ultrasonic waves of bats were inaudible to humans, and there were clear calls in the caves. He took this question back, and more and more naturalists came here to explore, but to no avail.
It was not until 1954 that Dunell Griffin, a professor at Cornell University in the United States, and a famous ornithologist, William Phelps Jr., came here with a full range of equipment and used the same method as bats to detect why oily owls can fly in the dark.
After experimental tests, Griffin found that the oil bird does have the same "echolocation" skills as bats, except that the ultrasonic waves it emits are acceptable to the human ear, so it can be heard, according to his research, he found that the oil bird in the absence of obstacles, the call is about 7000 hertz, when there is an obstacle, the sound will be sharper, and the closer to the obstacle is sharper, the sharper, this call will exceed 7000 hertz, which will hurt the human eardrum.
Griffin's move protected the oily plovers, whose population rapidly declined under the hunting of the Indians. After Griffin discovered the special function of the oil owl, the oil owl became famous. In 1958, the Venezuelan government established a national park in the Cabri Caves to protect the oily owl, and many tourists came to see the "bird with radar".