Stump-Tailed Macaque, Near Kaeng Krachan National Park, Thailand

This male stump-tailed macaque might look aggressive, but he was just having a good yawn (while displaying the results of his lack of proper brushing technique). Photographed on the Malay Peninsula of Thailand. Nikon D810 with Nikkor 200-400mm lens (at 240mm) ISO 800, f/4 at 1/160th of a second.