The Karen, a group of people living in the jungles between Thailand and Myanmar, consider gibbon intestines stewed in feces a delicacy. People liken them to anything from steak to candy to a milkshake depending on how gullible you look. Gibbons haven't had much luck around Chiang Mai either, where poachers have stolen babies to sell as pets and their habitat is quickly being replaced with farmland to feed humans. But things aren't hopeless - organizations like Treetop Asia (of Flight of the Gibbon fame) are working to not only reintroduce gibbons, but rebuild their habitat as well.
First off, calling a gibbon a 'monkey' is insulting. Gibbons are apes, just like chimpanzees, gorillas, you and everyone you know. They aren't smart enough to use tools or say strange things in sign language, so they're generally classified as 'lesser apes'. That's also kind of insulting.
Gibbons live only in Southeast Asia. There are many different kinds but the one we're talking about is the lar gibbon, which inhabits a narrow band from the very south of China, through Thailand and all the way down to the tip of Malaysia. They're largely gone from China, where they've all been eaten or pushed into Myanmar, and habitat loss in Thailand has drastically reduced their numbers. Poachers have also preyed on them for decades, killing mother gibbons and taking their babies to be sold into the pet trade. You may have seen some of these on the streets of Pattaya, Patong or other such upstanding areas.
The hills around Chiang Mai were once home to many gibbons, but now they only exist deep in the interior of Doi Suthep National Park and are rarely seen. In the forests of Mae On and Mae Kampong, about 45 minutes east of town, the folks at Flight of the Gibbon are raising gibbons and filling valleys with fruit trees in an effort to build them a home.
You probably know Flight of the Gibbon from their awesome jungle zipline courses. Even though there are now at least five companies that offer something similar, Flight of the Gibbon seems to be the only one that actually runs its own conservation programs supported with their own profits. If you'd like to see what they do, they often organize tree plantings where you can get your hands dirty in the jungle.If you're interested in helping out, or even just checking out their ziplines, you can find more information on treetopasia.com.