Recent findings revealed that over half of the world's primates are threatened by extinction. Based on the announcement by scientists on Tuesday, this includes apes, monkeys and lemurs.

The threat follows because of massive habitat destruction including burning and clearing forests and extensive primate hunt for "bushmeat" and smuggled wildlife trade. Some reports also point farmers are hunting them for trophies while others to care for as pets.

Together with the Sumatran orangutan, the list added two more, counting the Philippine tarsier and Madagascar's Lavasoa dwarf lemur, which was only discovered in 2013. "This research highlights the extent of the danger facing many of the world's primates," Bristol Zoological Society's director of conservation Dr, Christopher Schwitzer said. "We hope it will focus people's attention on these lesser-known primate species, some of which most people will probably have never heard of."

The world has 703 species and subspecies of primates. In 2013, 48 percent of these were on the brink of extinction; this year, the figure rose up to over 50 percent. And Madagascar and Vietnam are home to these highly endangered primates.

Primates such as Lavasoa dwarf lemur and Roloway monkey in Ghana and the Ivory Coast are claimed to be "on the very verge of extinction." On the other hand, Africa's red colobus monkeys as well as South America's howler and spider monkeys were also brewing some threats. "All of these species are relatively large and conspicuous, making them prime targets for bushmeat hunting," according to the statement.

Meanwhile last April, the Bouvier's red colobus was reportedly seen in Congo. This species has been presumed to be long dead and gone, since for a century, there had been unwarranted sighting.

"This report makes scary reading for primatologists and the public alike, and highlights where we as conservationists must focus our attention over the coming years," Schwitzer said. In addition, International Union for Conservation of Nature's species survival commission chair Russell Mittermeier looked forward that the government will take actions on the "desperately needed biodiversity conservation measures."

The report Primates of Peril lists the 25 most endangered primates between 2014 and 2016. Their approximated numbers are also calculated.