The WWF says a Javan rhino was captured on video attacking a camera set up in an Indonesian jungle to study the animal's habits. Experts say the rhino may have sensed the lens was a threat to her calf.
There are about 70 Javan rhinos in the wild, about 60 of which live in Ujung Kulon National Park on the western tip of Java island.
In the first month of operation, five infrared video traps have captured two images of the camera-shy mother and calf, says a spokesman for the environmental group.
"It is very unusual to catch a glimpse of the Javan rhino deep inside the rain forest," Adhi Rachmat Hariyadi said.
Hariyadi, head of the Ujung Kulon project for the WWF, said the camera was undamaged and put back on its stand the day after the incident.
Apart from the 60 Javan rhinos, there are thought to be around 300 Sumatran rhinos still alive in isolated pockets in the forests of Malaysia and Sumatra island.