More than half of the world's primates are on the verge of becoming extinct due to widespread destruction of their habitats by humans, international experts warned in a report Tuesday.

The International Union for Conservation of Nature's Red List of Threatened Species now classifies more than half of the world's primate species as being threatened with extinction. IUCN's latest report, "Primates in Peril: The World's 25 Most Endangered Primates, 2014-2016," says the main threats to primates continue to be the burning and clearing of tropical forests, the hunting of primates for food and the illegal wildlife trade.

Among the 25 most threatened are five primate species from Madagascar, five from continental Africa, 10 from Asia and five from Central and South America, according to Xinhua.

"The purpose of our Top 25 list is to highlight those primates most at risk, to attract the attention of the public, to stimulate national governments to do more, and especially to find the resources to implement desperately needed conservation measures. In particular, we want to encourage governments to commit to desperately needed biodiversity conservation measures," said Russell Mittermeier, chair of the IUCN/SSC Primate Specialist Group.

The most endangered on the list is the Hainan gibbon, of which an estimated 25 individuals are left in the wild on Hainan Island in China. The Northern sportive lemur from Madagascar is thought to be the second most endangered primate on the list, with only 50 surviving in the wild. Only 60 Cat Ba langurs, also known as golden headed langurs, are thought to remain on Cat Ba Island in Vietnam. On the most endangered list for the first time are the Philippine tarsier and the Lavasoa Mountains dwarf lemur from Madagascar, according to AFPAlso included on the list are Grauer's gorilla, the Northern brown howler monkey and the Sumatran orangutan, which has been at risk for some time.

In Africa, the red colobus monkey was particularly threatened, as were some species of howler monkeys and spider monkey in South America. Less than 250 mature Northern brown howler monkeys are living in the wild.

Scientists have identified 703 remaining species and sub-species of primates, according to AFP.

"This research highlights the extent of the danger facing many of the world's primates," said Christoph Schwitzer, a primatologist and director of conservation at Bristol Zoological Society who helped compile the list, according to The Daily Mail.

"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, such as the Lavasoa Mountains dwarf lemur from Madagascar - a species only discovered two years ago - or the Roloway monkey from Ghana and Ivory Coast, which we believe is on the very verge of extinction," Schwitzer said. "Some of these animals have tiny populations remaining in the wild and support and action to help save them is vital if we are to avoid losing these wonderful animals forever. 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."