Scientists trekking through unexplored regions of the island of Sumatra in Indonesia have uncovered a previously unknown population of Sumatran orangutans. The discovery of the 8,000 giant apes is a boon for the critically endangered species, bringing its estimated population up to more than 14,000.

"It was very exciting to find out that there are more Sumatran orangutans than we thought, but this does not mean that we can be complacent," Serge Wich of Liverpool John Moores University, who led the published study, said in a statement. "Numerous development projects are planned in the area that — if they are not stopped — could sharply reduce the number of orangutans over the coming years."

One of only two orangutan species in the world, the Sumatran variety is critically endangered due to rampant deforestation and development in Sumatra. Over the last 35 years, the massive island (the sixth-largest in the world) has lost 50 percent of its rain forest to industries such as palm oil and logging. These threats have not only devastated endemic populations of orangutans, but also tigers, rhinos, elephants, and hundreds of species of birds and fish.

Should deforestation remain unchecked, scientists estimate that as many as 4,500 orangutans could disappear by 2030. Surveys such as this one offer critical evidence to support future conservation for species found nowhere else on the planet.

"We would like to see appropriate environmental impact assessments conducted for all developmental planning that concerns forests in the orangutan range so that disruption to their habitat may be avoided or reduced to a minimum," Wich added.

While humanity is the single biggest threat to the Sumatran orangutan in the short term, the species is also at the mercy of another looming giant on Sumatra: the Lake Toba supervolcano. The largest volcanic lake in the world, its eruption some 75,000 years ago was the biggest recorded and may have caused a decade-long "volcanic winter." Despite currently dormant, researchers say the supervolcano could erupt any moment.

"A quake could reactivate the magma chamber which is so far dormant," Rovicky Dwi Putrohari, president of the Indonesia Geological Experts Association, told the Jakarta Post. "That's why we believe Mount Toba could erupt again at any time. When it will be, we don't know. Thorough and continuous research is needed to find that out."