For a certain palm tree that grows in the tropical regions of South America, a species called the "long-eared umbrella bird"
The exotic birds may be the masters of their fate.
In the tropical rainforest of South America, a mature palm tree can reach more than 30 meters,
Its leaf crown points directly to the firmament and rises above all the surrounding trees. In the competition for space and sunlight, rainforest trees compete fiercely. Around every towering mature palm tree, many of its sisters of the same kind have died in the process of growing. So what determines their very different fates? A strange bird called the "long-eared umbrella bird" may be the one who determines their fate.
In the tropical regions of South America, a type of palm tree called a "shed" is widely distributed. Its date-sized purple-black fruit is the main food source for mammals such as tapirs and wild boars, while for the local indigenous people it is both food and a curative medicine.
They make it into a thick, nutrient-rich drink that has a nutty flavor when drunk. Many birds in the rainforest, including the largest and prettiest macaws and toucans, also feed on the fruit of this palm tree.
However, in the Choco region on the other side of the Andes, the fruit of this palm tree became a major food source for a rare long-eared umbrella bird. In return, the long-eared umbrella bird also provides great benefits for the reproduction and growth of this palm tree. Choco is a characteristic biogeographic area that winds its way down the western side of the mountain range to the coasts of Colombia and Ecuador, where it has typical tropical rainforest features, even more humid than the Amazon basin, and contains a large number of local flora and fauna.
For several years, Thomas Smith, a biologist at the University of California, Los Angeles, has been studying the long-eared umbrella bird in this part of Ecuador and its role in the reproduction of palm trees and other plants.
The long-eared umbrella bird is a rare bird that grows in the Choco region, with a charcoal-black body, a large and personable body, and its wingspan can reach more than 60 cm. The male of the long-eared umbrella bird has a huge crown feather that looks like a back-combed back hair, and some even cover the head completely. The term "umbrella bird" comes from its distinctive crown feathers. The male also has a long earlobe, covered with thick feathers, that hangs from the neck to the tail, even beyond the tail, about 50 centimeters long, and looks like the fluffy crease on the dress shirt. Meat sagging plays an extremely important role in sexual display activities. The female is a little smaller than the male, and her appearance is far less exaggerated than that of the male. Natives in Ecuador refer to this bird as the "cow bird". They are given this name because the male's call sounds a lot like the "mooing" sound of a cow. In order to lure the female, the male bird's call is very loud and can be transmitted for more than 800 meters.
Despite its peculiar appearance and strange call, the long-eared umbrella bird is still unknown to most people. Finding an umbrella bird in the dark jungle is not easy, and even biologists often rarely see it. The long-eared umbrella bird inhabits this primeval forest, which is currently threatened by deforestation. It is conceivable that once this primeval forest disappears, the extinction of the long-eared umbrella bird will not be far away. The long-eared umbrellabird is currently on the brink of extinction, with populations declining by at least 30 percent over the past decade to less than 10,000 remaining.
In turn, the decline in the population of the long-eared umbrellabird also has a negative effect on the reproduction and growth of palm trees. Smith's research shows that the palm trees here rely mainly on flying animals to sow seeds for them. On the surface, this role of flying animals is not obvious, but in fact, their important role in the rainforest ecological environment cannot be underestimated. Whether the seeds can be spread from the mother tree to the right place to grow is the key to whether they can grow into timber. In the forest, although other birds and mammals also eat the fruit of this palm tree, they can't catch up with the long-eared umbrella bird. Long-eared umbrella birds fly in flocks to palm trees for several hours. When they feel hungry, they fly to a bouquet of fruit hanging from a branch, circle around like hummingbirds, then suddenly peck, swallow it, and then return to the perched branch to digest the food.
Scientists have found that birds flap their wings and fly away after eating and drinking enough, often carrying some seeds in their stomachs that have not yet been fully processed. The fruit stays in the belly of the bird for about 1 hour, during which time the thick oil of the seed is degreased. When the nutrients are removed, the seeds are regurgitated by the birds and fall to the ground. Wherever the bird flies, the seed is taken wherever it is. Seeds that have been ruminated by birds, if they fall on fertile soil, will take root and begin a long, variable growth process. If a seed is attacked by insects or other seed-eating predators, or falls in a place where grass does not grow, causing the seed to dehydrate, the seed will die before it can germinate. In this way, the long-eared umbrella bird does play a crucial role in determining the life and death of the palm tree.
In addition to being busy looking for food, the long-eared umbrella male has a more urgent thing to do, that is, mating. During the mating season from August to February, flocks of male birds (5 to 15 birds per group) gather every morning and in the afternoon in what is called a "mate field", each with an area of about 0.2 square kilometers. Most male birds will mark their territory in the mating grounds, forbidding "others" to enter. Before dawn, the male bird first chooses a suitable perch to sit on, and then makes a cow-like moo, and the sound echoes in the forest for a long time...
As the day grew brighter, the males began to stretch their crowns, their earlobes swinging up and down rapidly, the feathers bulging up and down, their wings spreading out like vultures, and they also made strange "clucking" sounds. After that, they flapped their wings quickly, and the sound sounded like the sound made by a falling dog when he shook his head desperately to dry up the water on his body. Sometimes, they pull a small branch from the perch and tap on the branch or body of the tree. They perform like this every morning and in the afternoon, lasting up to several hours. Occasionally, they would fall from the branches of a tree due to excessive performance.
The male performs as hard as he can, bent on making a good impression on the female. Females spend most of their time outside the mating grounds and rarely mingle with males. But as soon as the breeding season comes, they will come to the mating field to find a mate in order to breed offspring. At this time, each male strives to prove to the visiting female that he is the best mate, and the female generally does not make a hasty decision, and they have to make a wide selection.
At first, the female just wandered around the mate selection field, listening to the male birds and not walking into the mate selection field. After a day or two, the female may visit the male bird that sounds particularly good to her. It first quietly flew to a tree 10 to 15 meters away from the mate selection field and perched there. Once the male finds the female, he begins to sing with all his might, his head swinging up and down, his earlobes swollen, his wings spread, and he shows off his heart. The female sits quietly on the perch, intently grooming her feathers, seemingly oblivious to the male's exaggerated performances, and in fact all of her senses are watching the male's every move.
If the female is visiting the male for the first time, it will fly away after a few minutes and then quietly return. Before determining a mate, the female will generally visit multiple males and even visit several mate selection grounds. Sometimes it will return to the same mate field for several days in a row. Sooner or later, it will always identify a favorite male bird and stay in its territory for a long time. After the female bird determines her "crush", she will fly to a tree only 30 to 40 centimeters away from the male bird and perch there. At this time, the male will slowly approach him until he is close to it. After a moment's hesitation, the male begins to inflate the crown, the earlobes swell to their maximum, and then make a "cow" call or two for a final test. Then, it swung its head vigorously in front of the female, then wrapped its earlobes around the female's neck and finally rested on her back, looking like a long female scarf. Under the intimate embrace of the male, the female's eyelids droop low, signaling consent to mating. The male seizes this rare opportunity to jump from behind the female to its back and begin mating. Although courtship takes several days, intercourse lasts only a few seconds before it ends. Sometimes with a turn of the face, the male bird has jumped off the female's back and stood next to it. After mating, the female uses her beak to sort out her feathers and then flies away without looking back.
After the "honeymoon", the females begin to live alone again. It returned to its own territory and began to build nests. Smith and his team recorded how well females nested and how long sperm remained in their bodies before fertilizing their eggs. They found that many females were able to store their eggs for months before fertilizing. During incubation, the female incubates, feeds, broods and nurses the chicks alone, and even if the young birds are full of wings and can fly out of the nest, the female continues to feed them until the young birds can live independently, and they are "competent mothers".
Unlike females, males continue to use the mating grounds as the center of their activities. For several months of the year, male birds live in the mate selection field, except for foraging, they never go out of the mate selection field, they are very obsessed with this place. Of course, they can't see how their children were born and raised, and even if they face each other with their children, they probably don't know that the other party is their children. By human standards, they are "incompetent fathers," however, many birds live that way.
Smith speculates that the mating behavior of the long-eared umbrellabird may have played a crucial role in the spreading of palm trees and other plant seeds. To test this idea, he captured several long-earlobe umbrella birds, half male and female, and he attached disposable miniature radio transmitters to their tails and released them. In the months that followed. By receiving signals from radio transmitters, he recorded where the birds landed while foraging or making a sexual display. He also kept several birds in bird cages, fed them with palm tree fruit, and then recorded how long it took them to regurgitate seeds. By mastering how the birds move and how long plant seeds stay in their stomachs, Smith can estimate where the birds have withdrawn the seeds they eat.
Now, Smith is sure that the males have withdrawn almost half of their seeds into the mate selection grounds; the females have spread seeds much more extensively, almost the entire forest area.