There are 6 billion humans on the planet today, and with that number come all of the demands of supporting life. People need land to live on and to harvest food from. There are minimal limitations on how much land each person can own, and people are playing “finders, keepers” with natural resources all over the world. Any time humans invade untouched territory, they push previous inhabitants out. This includes the already vulnerable primates.
Simply put, primates are being kicked out of their homes. There is not enough land available to allow their populations to flourish. Apes and monkeys generally live in tropical areas in or near rainforests, miles of which fall every day as they are logged, razed or otherwise destroyed or plundered.
International trade in tropical hardwoods is one of the main reasons for rainforest loss. Sumatran orangutans in Indonesia are at great risk of extinction due to unsustainable palm oil farms which people plant over their natural habitat. Primates in Madagascar are especially susceptible since only 10 percent of their original habitat remains. Great apes in particular are vulnerable to all of these pressures because their birth rate is so low. In the face of the coming climate change, conditions are likely to get much worse.