Hidden cameras in the jungles of Indonesia's Java island have captured rare footage of the world's most threatened rhino, boosting efforts to save it from extinction, conservationists said Thursday.

Two camera traps set up in the remote Ujung Kulon national park yielded new footage of the endangered Javan rhinoceros, said Adhi Hariyadi, leader of the project by the environmental group World Wildlife Fund (WWF).

The footage will help conservationists fighting to save the species, which numbers only around 60 in the wild, by giving new information on the rhinos' health as well as vital insights into their breeding habits, said Hariyadi.

"We have already been able to observe a mother and calf walking and rearing and in the process of separation," he told AFP.

The motion-triggered, infra-red cameras caught night-time footage of one female rhino and her calf in the lush forest of Ujung Kulon.

Seeing the unfamiliar device hanging against a tree, the mother charges the camera with a full-force headbutt and the picture disappears.

In spite of the blow from the rhino mother's head, the green camera box was retrieved and set up to capture more footage the next day, Hariyadi said.

The footage will be key in efforts to save the endangered species, Hariyadi said. The roughly 50 Javan rhinos living in Ujung Kulon make up the only viable population capable of reproducing.

Despite the rhino knocking the camera to the ground, the footage of mother and calf beforehand will be useful for understanding how the Javan rhinos care for their young, and how and when they force their children to fend for themselves, he said.

"(The footage) basically fills in the puzzle, and since we are challenged to increase the population of Javan rhinos in the future it basically helps us to identify suitable environments for them," he said.

"We know very little about their behaviour unfortunately."

Conservationists and the Indonesian government are studying the possibility of relocating some of Ujung Kulon's rhinos to a new home on either Java or Sumatra island to avert catastrophe if the community collapses.

"If something happens to this population they will be all gone," said WWF spokeswoman Desmarita Murni.

"Knowing how they live we can find a way to protect them to prevent them from going extinct from disease or competition from other animals for food," she said.

The new footage is the first to be taken of the Javan rhino from camera traps and the first from any source in the last five years, Hariyadi said.

The Javan rhino, which is distinguished by its small size, single horn and loose skin folds, is likely the most endangered large mammal on the planet, according to WWF.

Roughly 90 percent of the world's Javan rhinos live in Java's Ujung Kulon park, an oasis of wilderness on the western edge of one of the world's most densely populated islands.

The Javan rhino is classified as critically endangered by the environmental group and none of the animals currently live in captivity.