In comparison, the religious self-mutilations performed by the devotees during the Vegetarian Festival in Phuket are considered to be extreme and shocking. The entranced devotees who perform these acts of religious self-mutilation are called mah song. They wear elaborate costumes, enter into trances and ask the gods to enter their bodies. Men or women (they are usually celibate) puncture their faces with hooks, spears and knives amongst other sharp implements.
The Yuen Po street Bird Garden in Hong Kong was built in the late 1990's after the former "Bird Street" at Hong Lok Street was demolished. It was built to preserve the spirit and popularity of the bird stalls that once were in Mongkok. The Chinese have traditionally liked to keep birds as pets, and this tradition is maintained in this small garden. Men (I've not seen a woman there except those selling birds, birdseed and live crickets) walk around; whistling at the caged birds, from delicate canaries to colorful parrots, admiring their plumage and a few walking their pets in cages.
Readers of The Travel Photographer blog know of my current long term involvement in documenting Chinese Opera of the diaspora; an involvement that will culminate into the production of a coffee-table book bearing the same title. It is for this reason that the blog has been recently populated with posts with excellent work of Chinese opera by travel and documentary photographers.
You cannot always ask permission, of course. If you are shooting a street scene or a wide shot of a market, you can't run up to everyone and ask if it's OK. In general, people do not mind this sort of photography—it's only when they're singled out that they get uncomfortable. But not always. Be sensitive to the scene in your viewfinder. If people are getting nervous, ask permission or move on.
I have found Alessandro Bergamini's China gallery to hit all the right notes in that regard. Most of his images were made in Guizhou; a province located in the southwestern part of the country, and well known for its traditional rural villages, inhabited by minority groups like the Miao and Dong. Other images in the gallery were made in Guangxi , another autonomous region bordering Vietnam, and home to the famous cormorant fishermen of Guilin. I haven't been but I read that even though the water is too polluted now for fishing to be sustainable, these fishermen are catnip for many photographers, and earn their living in that fashion.