In northeastern Brazil, in the woods so dry that the trees blanched bony white, the termites were busy working for millennia. The only external signs of their labor are dirt, garbage dumps from their underground excavations. Dirt and garbage usually inspire so much respect as cutting off the legs – but these are truly wonderful piles.
Conical embankments, each about 8 feet high and 30 meters wide, are erupting from the ground at regular intervals, located about 60 meters from each of the six neighbors. From the air, the model evokes a counter or hexagonal combs in a basket. A map of satellites, via Google Earth, shows that the moors cover more than 88,000 square miles, an area larger than Minnesota.
"Imagine being a city," says Stephen J. Martin, an entomologist and expert on social insects at the British University in Salford. "We never built a big city." And the centimeter termites, Syntermes dirus, made that grain from grain.
In total, the earth excavated from the termites is equal to the volume of 4,000 pyramids in Giza, as Martin and his co-authors publish in a study published on Monday in Current Biology. They collected samples from the centers of 11 mounds, and by measuring the radiation in the mineral grains, it was found that the oldest grave site is about 3,800 years old. Maybe others are older. Based on satellite imagery and on-site inspections thousands of miles away, scientists estimate 200 million sandy landscapes.
If the forest cover disappears, exposing the moons in all their splendor, this place will be celebrated as a natural "wonder of the Earth," Martin said.
Still tilted under trees and a thorny brush, tombs can be difficult to notice. Martin failed to notice them in the beginning. He traveled to a harsh forest in Brazil, called katoing, looking for bees. Only after miles of driving, where the road is cut through the trees to reveal the shape of the wetlands, he saw them. These are the term-mounds, said the locals for Martin.
"No, that can not be right – there are too many of them," recalls the thinking. Back in Britain, his colleagues told him that the moons must be a lake sediment or other geological feature.
The locals, of course, were correct, as Martin revealed when he returned. Majmus of any larger city while walking near a swiming hole, the entomologist struck another biologist, called Roy Funch.
"He walked along the river with a friend and I went down the river to go swimming," said Fanch, co-author of the new paper. Martin "looked like, apparently, an outsider," so Funch, who also works as a tourist guide, greets, he greeted me and asked me what Martin had come to Brazil. The thermal mounds, Martin said, complaining that nothing appeared in Google Scholar.
"I said," Hey, I just met the only man in Brazil who works on these mounds, "recalls Funch." So, you know, "serendipitous" is putting it easy. "
Funch traveled to Brazil in the 1970s with the Peace Corps. Beautiful mountains and hiking trails have persuaded him to settle in the northeast of the country, he said. He also fell under the magic. The tallest, which Fünch calls "babbling embankments", reaches 15 meters in the air. (Not all of them are still active.)
"I do not think anyone has ever seen such a modification of the landscape of such enormous proportions from so small small creatures," he said.
In the 1980s, Funch, who describes herself as a "scientist from the background," but has a doctor in botany, writes about the termite graves for a popular scientific journal. He hoped to attract the attention of other researchers. No one else. Thirty years passed, and he decided to study himself, until he teamed up with Martin.
These mounds, unlike other hives, are not nests or ventilation shafts. "We felt that the nest would be in the middle of the tombs," said Fanch. "They were not. They were not even under the graves." A large tunnel, about 10 centimeters (about four inches) in diameter, rises through the center of the embankment. Thermites deliver waste and attach the tunnel to the top.
"No one has ever found the nests of the queens. We really do not know what's going on under the ground." "Absolutely nothing," said Funch.
The graves make non-cooperative subjects. Termini soldiers emerge when researchers impair dirt. They will draw blood, Martin said. "They have sharp mandibles, they will cut directly through the skin," he said. The bad soil of nutrients is a nightmare to dig, baked like concrete in heat.
The distance and the poor soil are many qualities that enable the Thermal embankments to withstand. The area has long sushi, says the University of Buffalo Geophagus Eun-Hugh Yu, author of the study. (Yuo also met with Funch in a tourist town in Brazil, "It's a good place to get to know people," he said.) The climate, although not friendly to human agriculture, is stable. In this difficult environment, the Thracian kingdom flourishes.
"These terms used this area and did very well for themselves," Martin said.
The wet season lasts about a month. The cation rises from brown to green and returns again. The trees are blooming, and they throw away the leaves as quickly as possible. Within a few weeks, the forest floor is devoid of leaves. Termites take everything to eat. Martin suspects that the trash keeps them until the end of the year. Termites elsewhere are grown on fungi of foliar dermatitis, but in South America there are no known termite fungi species.
Scientists have no definite explanation for the unusual hexagonal distance of the tombs. The model is "absolutely striking and quite unusual in its size," says Corina Tarnita, a mathematical biologist at Princeton University, who was not involved in the new job. The only similar model in nature that is so widespread, she said, is an African fairy, circles in brushes that appear from Angola to South Africa.
But Martin suggested this, because these social insects "are very, very good for optimization," the six-point system may be the most effective. The dirt, as seen from the fiber optic cable, is a large and interconnected tunnel system. The termites are derived from pheromones, the equivalent of insects of a conductor on the subway.
"When you have enough connections, it is very easy to find the nearest embankment," Martin said. Only if the stock does not exist on the edge of the megalopolis will begin to build a new one.
Tarnita warned that the graves tested in this study were made so accidentally. "It would really be important to have a systematic assessment of the age that gives a certain feeling about the relationship between the age of the mound and its neighbors or neighbors of neighbors," she said.