John Shaw / Snow monkey or Japanese macaque (Macaca fuscata) female with baby clinging to her back. Jigokudani, Japan, February.

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 baby, Jigokudani Valley, Nagano Prefecture, Japan. June.

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

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

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

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.

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

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

Yukihiro Fukuda / Japanese macaque (Macaca fuscata fuscata) mother with rare white furred baby, 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

Aflo / Japanese macaque (Macaca fuscata) mother cuddling baby, Yamanouchi, Shimotakai District, Nagano Prefecture, Japan. June.

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.

Anup Shah / Japanese Macaque (Macaca fuscata) baby sitting on the edge of thermal hotspring pool. Jigokudani Yean-Koen National Park, 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.

Diane McAllister / Japanese Macaque (Macaca fuscata) pair rest together on a rock near the river in Jigokudani, Japan.

Diane McAllister / Japanese Macaque (Macaca fuscata) adult with wet snowy head in the hot springs of Jigokudani, Japan.

Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile riding on its mother's back, along snow trail in Jigokudani, Japan.

Diane McAllister / Japanese Macaque (Macaca fuscata) adult in the hot springs of Jigokudani, in the snow, Japan. February

Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile portrait, Jigokudani, Japan. February

Ben Cranke,Ben Cranke / Japanese Macaques (Macaca fuscatata) grooming in hot springs, Jigokudani, Nagano Prefecture, Honshu, Japan

Ben Cranke,Ben Cranke / Japanese Macaque (Macaca fuscatata) juvenile, reaching out to touch the camera, Jigokudani, Nagano Prefecture, Honshu, Japan

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile approaches the hot springs and feeding area covered in icy snow from the cold night before in Jigokudani, Japan, January

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) young one, appearing quite relaxed in thermal pool, even falling asleep, in Jigokudani, Japan, February

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) male and female huddle together during a light snowfall in Jigokudani Japan, January

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) with icy strands of fur on its head, Jigokudani, Japan, February

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile appears to be doing tricks to get some attention in Jigokudani, Japan.

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) females gather at one end of the hot springs, Jigokudani, Japan, February

Diane McAllister / Japanese Macaque (Macaca fuscata) biting needles from tree branch while sitting in hot spring in Jigokudani, Japan, January

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile standing up with feet pointed inward, Jigokudani, Japan, January

Aflo / Two Japanese macaques (Macaca fuscata) sleeping with awake baby, in snow, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Male Japanese macaque (Macaca fuscata) walking along path through deep snow, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Juvenile Japanese macaques (Macaca fuscata) two years old, playing, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) nursing one month old baby, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddled together sleeping in a tree at night, full moon, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) searching for nuts with young watching, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) family huddled together for warmth on a cold day, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) eight months old sitting in front of a pool created by a hot spring being used by females and young for bathing to keep warm, Jigokudani, Joshinetsu Kogen NP, Nagano...

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) holding young while bathing in hot spring to keep warm, only females and young bathe, winter, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Yukihiro Fukuda / Female Japanese macaques (Macaca fuscata) in a hot spring to keep warm, only females and young bathe, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan