Revealed: Elephants and gorillas hang out in a hidden playground

Hidden playground for elephants and gorillas revealed in Republic of Congo rainforest

Written by Wang Zhengyang

Elephants and gorillas living in the rainforests of the Republic of Congo spend much of their time hiding in the shadows, or so we thought. Using drone surveys and artificial intelligence processing, scientists discovered an extensive network of mysterious grass and sedge clearings. Elephants, gorillas and other iconic animals visit this muddy concourse. by It is spoken in the indigenous language of the Baka people to absorb vital nutrients and maintain complex social networks. Many playgrounds can be seen in satellite images, and AI-powered processors can help researchers find them more effectively.

Recognition of the incredible reach of the bai network began in the field. In May 2021, Sylvain Ngouma, a local botanist in Ozala-Cocoa National Park in northern Republic of Congo, led a small team of researchers to explore kudzu in the lush rainforest. Evan Hockridge, then a second-year graduate student at Harvard University, was searching for the paper with Ngouma. In the forest, a 150-foot-tall canopy of kapok and red ironwood abruptly ends in an unobstructed meadow the size of Times Square. Ngouma points to a pair of wet, pot-sized footprints leading through the forest to an open roundabout.Les Elephants”

Hockridge, who was planning to study the behavior of forest animals, said he thought Bay was an anomaly in his data collection. When I was there, what came to mind was this giant bai with a buffalo in the front and an elephant in the middle… Understanding animal interactions without first understanding bai It is not possible. ”

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Over the next four summers, researchers surveyed the vacant lot. They first sifted through more than 2 million camera trap images placed around 13 known bays. They confirmed what many local Congolese people told them these natural clearings were important gathering places for some of the world’s most endangered mammals. Among the regulars: Forest elephants gather to consume the nutrient-rich soil. Western lowland gorillas feed on the roots of biphytes, which contain a lot of salt. Forest buffalo, blue duiker, sitatunga and even bongos (forest-dwelling antelopes worshiped as spirits by the area’s inhabitants) graze around Bai. The ungulates, in turn, attract predators such as spotted hyenas and lions. Researchers have found that bays are a big melting pot, a big playground for forest animals.

“It’s so magical to watch a family of elephants, gorillas, or giant forest pigs come out from the edge of the forest, soak up the sunshine and socializing opportunities, and then retreat back into the cool shade of the deep forest. ,” says Deputy Director Vicki Fishlock. Research at Amboseli Elephant Trust, which was not involved in the current study. Bai is like a Viennese cafe, a social place where animals hang out. The elephant family gathers and their children are introduced. In open spaces, you can clearly see each other. According to Ozara Park management, the calf spends a lot of time playing in the mud and chasing birds. Female gorillas closely observe solitary males and decide whether to join. Herbivores use their calves to graze, probably because clearings make it easier to find predators.

During initial surveys, the research team often followed elephant tracks in the rainforest, so-called elephant boulevards, moving from bai to bai. This made Hockridge question the network. Previous studies have recorded the animals’ behavior in selected bays, but no one counted them or had the means to map their distribution.

To do that, we need to take to the sky. Partnering with Ozara Park Management African Parks, the team flew a drone equipped with high-resolution lidar over some of the 220 bays already known to park rangers to collect structural and spectral features. The researchers used this information to train a machine learning algorithm to select bis from satellite images. The results were announced on October 1st. ecology. Hockridge and Ngouma mapped all the bays in a national park the size of Connecticut and discovered 2,176 of them. That’s 10 times the number park officials previously knew. (Disclosure: The author of this Scientific American article was previously in the senior study author’s lab at Harvard University but was not involved in this research.)

The forest agora is always located near a river or stream. Most are smaller than a city block, but some are larger than a college campus at over 100 acres. “Especially in the West, we often think of rainforests as a continuous ocean (of trees), but we need to think about where forests disappear,” says Hockridge, lead author of the paper. “Bays are ultimately islands of resources, and animals essentially generate these network of routes to get in and out of the nodal network of the bay.”

The researchers’ map of Bai, the first of its kind, is also a map of conservation priorities. “We now know that a large part of the animal kingdom depends on this unique ecosystem, and these species have no alternative habitat other than the bay,” Hockridge said. “We name many animals: forest elephant, forest However, when you look at their movement patterns and the amount of time they spend in corrals, they are almost like water buffalo. liquidation expert. ”

Andrew Davis, an assistant professor in Harvard University’s Department of Biological and Evolutionary Biology and the paper’s lead author, said it was only because of improvements in satellite resolution and computing power that observers could actually see the networks clearly. He said it was the first time recently. Davis hopes to apply the same algorithm to bay charts across the Congo Basin, the world’s second largest rainforest.

This research is also a step toward solving the ultimate mystery of how the bay formed. Many ecologists argue that a combination of hydrology and animal landscaping, particularly forest elephant landscaping, are at play. However, no conclusive evidence has been obtained. No one has recorded the formation or retreat of the bay. Now, with maps in hand and camera traps in place, researchers are tracking changes in the bay over time. This has implications for the maintenance of these important animal habitats. For example, will rampant ivory poaching affect elephant populations and, by extension, elephants?Will climate change cause bays to shrink or expand?

“We have a theory,” Davis confesses. “But the short answer is we don’t know.”