Wim van den Heever / Japanese macaque (Macaca fuscata) youngster jumping over small stream, Jigokudani, Nagano, Japan. February.

Yukihiro Fukuda / Japanese macaque (Macaca fuscata fuscata) mother with rare white furred male baby, Jigokudani Valley, Nagano Prefecture, Japan. June.

Yukihiro Fukuda / Japanese macaque (Macaca fuscata fuscata) rare white furred baby playing with flower, Jigokudani Valley, Nagano Prefecture, Japan. June.

Danny Green / Snow Monkey (Macaca fuscata) with snow covered paw in front of mouth, Nagano, Japan, February

Danny Green / Snow Monkey (Macaca fuscata) in snow, Nagano, Japan, February

Danny Green / Snow monkey (Macaca fuscata) close up with eyes cast down, Nagano, Japan, February

Danny Green / Japanese Macaque (Macaca fuscata) carrying young on back through snow, Nagano, Japan, February

Danny Green / Japanese Macaque (Macaca fuscata) carrying young on back through snow, Nagano, Japan, February

Mark MacEwen / Japanese macaque (Macaca fuscata) relaxing in hot spring in Jigokudani, Yaenkoen, Nagano, Japan, February.

Mark MacEwen / Japanese macaque (Macaca fuscata) sleeping at hot spring in Jigokudani, Yaenkoen, Nagano, Japan, February.

Diane McAllister / Japanese Macaque (Macaca fuscata) female holding baby close in snow, Jigokudani, Japan.

Diane McAllister / Japanese Macaques (Macaca fuscata) enjoy time soaking and grooming in the hot spring in Jigokudani, Japan.