Tarmizi, from the Leuser International Foundation, said Thursday that pictures from movement-triggered cameras identified a male and six female Sumatran rhinos in Aceh province's Leuser National Park as of April.
More than 1,000 images from 28 camera traps were taken since last July. The park's rhino population is estimated to be no more than 27.
There are an estimated 200 Sumatran rhinos living in the wild in small groups in Indonesia and Malaysia, half the number from 15 years ago.
An estimated 70 percent of the population has been lost since 1985, mainly to poaching and loss of habitat