The critically endangered Sumatran orangutan is now twice as many compared to previous populations estimates, however, researchers reveal that these primates still face imminent danger from their habitats.

Today, the disappearing forest habitats of the orangutans are the biggest threat of these creatures, along with illegal pet trading and poaching. In Indonesia, fires are spread out to clear land for developing palm oil plantations, as they continue to burn across the nation, damaging and destroying the apes' remaining homes.

According to lead author of the study, Serge Wich from the Liverpool John Moores University, there are now greater chances for the Sumatran orangutans to thrive in the near future, where there are now less chances of their numbers disappearing.

Wich and his team estimate that there are about 14,600 orangutans in the wild, as opposed to 6,600 of them back in 2008. These prior estimates reveals that the population went down by 80 percent in the last 75 years, according to Wich, although these new findings would not be a significant change to population numbers. He adds how there is much forest loss in Sumatra in the last decades that the population declined that significantly, although now, a bit less.

Wich noted that orangutan populations are still not increasing despite these new findings, but instead, this new survey examined the newly established orangutan habitats, that did not exist before.

Researchers conducted a survey among Sumatran regions some 1,500 meters in elevation, as past surveys readily assumed that there are no orangutans living up to 900 meters above sea level. The team also investigated areas that have been logged before where they were surprised to discover that orangutans are now repopulating these areas. Further into the western regions, surveys reveal that orangutan populations there are only recent.

Researchers now conclude that past estimates were drastically underestimated due to the apes' range, which is now 2.56 times as large than first thought. However, researchers also say that due to the impact of continuing deforestation in the region, around 4,500 individuals could perish by 2030.

Wich says that this new discovery of the Sumatran orangutans that are living in higher altitudes reveal new insights about these creatures. Prior observations suggest that these orangutans possess a different diet, consuming trees that are not eaten by low lying orangutans. These orangutans also use different tools, which can be classified as unique "cultural behavior".

This new discovery that orangutans continue to live in the forests even after logging suggests that they are more resilient to human impacts than previously believed. The team also says that this new population estimate would not change the animals' conservation status, which is still, "critically endangered" according to the International Union for Conservation of Nature.

Sumatran orangutans belong to two different species of orangutans. Bornean orangutans are about 50,000 to 60,000 in population numbers. Sumatrans also appear to have paler and longer fur with slightly longer faces, where they are the only great apes that thrive in Asia.

These new findings are detailed in the journal, Science Advances.