4 children were rescued after 40 days in the jungle. How did they survive?

Colombians are overjoyed that they have been found alive, surviving all that time in the jungle by themselves.

Here’s what to know about the rescue — and how the children might have survived.

When did the plane crash, and how were the children rescued?

The plane was flying from the southern town of Araracuara when it disappeared May 1, according to authorities. Searchers later discovered the wreckage and the bodies of the pilot, the children’s mother and another adult — but the children, who are members of the Huitoto Indigenous group, were nowhere to be found. A report said the children had been sitting at the back of the plane, which was less damaged in the crash.

Soon, rescuers came across clues that raised hopes that the children were alive. First, they found a pair of children’s tennis shoes near the site of the crash. Then, they found a diaper, a half-eaten fruit and a bottle in the jungle.

Rescuers later came across a makeshift shelter created out of sticks and branches, as well as a pair of scissors and some hairbands, according to the aviation authority. They also found small footprints, about two miles from the crash site.

There was confusion over the fate of the children, as Colombian President Gustavo Petro had earlier tweeted that the children had been found alive — only to delete his message the following day, saying he had not been able to confirm the news.

Gen. Pedro Sánchez, the commander of the Joint Command of Special Operations, told the Associated Press that the operation was like trying to “find a tiny flea in a huge rug that moves in unpredictable directions,” in a dense jungle with visibility as low as 20 yards or less, and up to 16 hours of rain a day that threatened to wipe away any signs of the children.

Previously: Four children are missing after a plane crash in Colombia. Here’s what we know.

More than 100 members of the military, as well as volunteers from Indigenous communities, took part in the search operations. The children’s grandmother recorded messages to the children in their native language, Huitoto, telling them to remain where they were.

On Friday, Petro announced that the children had finally been found by Indigenous communities taking part in the search, and the military. The country’s air force said they were found just over two miles from the crash site.

Colombia’s civil aviation body shared a video showing the children receiving medical attention aboard a plane as they were transferred from San José del Guaviare to the capital, Bogotá.

How did the children survive?

It’s not yet clear how exactly the children survived — but the Organization of the Indigenous Peoples of the Colombian Amazon tweeted that the children’s survival was “a sign of the knowledge and relationship with the natural environment of life, which is taught and learned from the mother’s womb and is practiced from a very early age.”

This was echoed by Fátima Valencia, the children’s maternal grandmother, who told Agence France-Presse that the eldest child, the 13-year-old, had a “warrior”-like nature and “always took care” of her younger siblings, including by giving them fruit from the forest. Their grandfather, meanwhile, said the 9- and 4-year-old brothers were very “skilled” at walking through the forest.

Carlos Peres, a professor of tropical forest ecology at the University of East Anglia in England who has worked with eight ethnic groups in the Amazon jungle, said in a telephone interview Saturday that the children’s knowledge of the forest would have helped them to survive.

“Four Western kids of the same age would have died” there, he said, but many children from Indigenous communities in the Amazon “mature very early” and at an early age learn basic skills for surviving in the forest, including how to find food and how to avoid predators. In some communities with which he has worked, children may begin climbing trees as early as 1 year old.

Obtaining water would not have been a problem, given the streams and creeks in the region, and members of Indigenous communities are able to build makeshift shelters quickly, Peres said, such as the one rescuers found last month during their search for the children.

He said the experience would have been traumatic for the children, “but they were also fighting for survival. And they would have known how to negotiate those conditions.”

For outsiders, “the hinterlands of the Amazon jungle sounds a lot more hostile than it actually is, particularly if you come from those places,” Peres continued. “In that part of the Amazon, there will be about 80 different species of snakes, but only five of those are venomous and they [Indigenous people] can distinguish poisonous from nonpoisonous snakes.”

“The only thing that I lament more than anything is that all that knowledge that saved these kids in this particular case is rapidly disappearing over the Amazon,” he added.

What has the reaction been?

Colombian officials have described the rescue of the children as a miracle. “A joy for the whole country!” the president tweeted Friday evening.

“They were alone,” he told local media. “They themselves achieved an example of total survival. It will remain in history, so those children are today the children of peace and the children of Colombia.”

The country’s child-protection agency wrote on Twitter that “seeing them again, safe and with their family, is an indescribable joy.”

“The four minors who survived the plane crash in Guaviare are the light of life and hope that illuminates Colombia,” the U.S. Embassy in Bogotá said as it thanked the Colombian armed forces “for the heroic search and rescue mission in such difficult terrain and for giving us this immense joy.”

Petro, the president, told local media that he hoped to speak to the children Saturday and that officials were awaiting doctors’ assessment of the children’s health.

“It’s been 40 days; their health condition must have been weakened,” he said, adding that it was also important to safeguard their mental health.