 Chatthin Wildlife Sanctuary, with the Mu next to its eastern boundary, was designated a wildlife sanctuary in 1941 for the conservation of the brow-antlered deer "Thamin" ("Cervus eldi thamin").There has been a decline in the population of large mammals since the end of WWII into the 80s, and these include tiger, bear, leopard, gaur, banteng, wild dog, barking deer and hog deer.White-winged duck ("Cairina scutulata"), an endangered species of forest duck, is native to the Mu river.