BALIKPAPAN, Indonesia — As the little red car stopped, the window slid down and a hand poked out, dropping some yellow crackers on the ground. A few seconds later, a group of southern pig-tailed macaques, a species of monkeys that live on the island of Borneo, flooded the area and instantly ate food.

Until recently, this road in the wilds of Indonesia was rarely used by humans or macaques, an endangered species that spends most of its time in trees. But with its refurbishment as part of the development of the new national capital, Nusantara, it is attracting macaques, who have found new road users to be a reliable source of food.

“Before that, they were rarely seen,” says Satvika Satria Prahita, a resident of the nearby port city of Balikpapan.

The Indonesian government says a new capital is needed because the 11 million inhabitants of the overcrowded current capital, Jakarta, face environmental threats including pollution, land sinking and rising sea levels. Construction has begun on a selected site 1,200 miles from Borneo, an island shared by Indonesia, Malaysia and Brunei that has one of the highest levels of biodiversity in the world.

Officials say Nusantara will embrace the concept of a “forest city” with more than 75% green space and that it will be carbon neutral by the time it is completed in 2045. But conservationists are worried about the impact on orangutans, dolphins and other wildlife in and around the new capital, citing the public’s lack of knowledge about conservation.

“Our big homework right now is to figure out how to educate people,” said Hadi S. Alikodra, professor in the Department of Forestry and Environment at IPB University in Bogor, Indonesia.

Experts urged the government to protect wildlife from construction workers, as well as the 1.9 million people expected to eventually live in Nusantara, which is scheduled to open next August. Otherwise, catastrophic conflicts could ensue between humans and animals, said Muhammad Ali Imron, a wildlife expert at Gaja Mada University in Yogyakarta, Indonesia.

“And that will lead to a loss of biodiversity,” he said.

Viratno, an official with the Ministry of Environment and Forestry, acknowledged the concerns but said the government is prioritizing wildlife protection.

“We will intensively train workers and all people in nature conservation and how to live among the wild in this forest city,” said Viratno, who like many Indonesians uses only one name.

He said that Nusantara’s 75 percent forest cover would make it an attractive place for animals to live. As a defense against human-animal conflicts, the government is setting up a wildlife response team and call center, he said.

Some of these potential conflicts can be dangerous. Conservationists say large-scale mangrove clearing and increased activity of large ships have already provoked crocodile attacks on local fishermen, leaving them in a stalemate.

“If I had a choice, I would rather go fishing during the day to avoid the crocodiles,” said Gasanudin, a fisherman from the village of Gersik. “But the result will be less than doing it at night or before dawn.”