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

Shane P. White / Japanese Macaque (Macaca fuscata) in hot spring, Jigokudani, Nagano, Japan

Jami Tarris / Japanese Macaque (Macaca fuscata) in hot spring, Jigokudani, Nagano, Japan

Dave Bevan / Slow motion clip of a Jay (Garrulus glandarius) feeding from a peanut string during a snowstorm, Carmarthenshire, Wales, UK, November.

Ingo Arndt / Japanese macaque sitting portrait {Macaca fuscata} Joshin-etsu NP, Japan

Ingo Arndt / Japanese macaque being groomed in hot thermal spring {Macaca fuscata} Joshin-etsu NP, Japan

Ingo Arndt / Japanese macaque head portrait {Macaca fuscata} Joshin-etsu NP, Japan

Cyril Ruoso / Golden monkey (Rhinopithecus roxellana) jumping over a frozen stream, Qinling Mountains, China. Sequence 2 of 7

Hiroya Minakuchi / Japanese Macaque (Macaca fuscata) young in hot spring, Jigokudani, Japan

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

Thomas Marent / Japanese Macaque (Macaca fuscata) mother with young in tree, huddling for warmth, Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata) parents with baby, Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata), Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata) in winter, Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata) mother carrying baby through snow, Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata) mother holding baby for warmth, Jigokudani, Nagano, Japan

Thomas Marent / Japanese Macaque (Macaca fuscata) mother and young in hot spring with juveniles grooming, Jigokudani, Nagano, Japan

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

Fiona Rogers / Japanese Macaque (Macaca fuscata), Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) pair grooming in a geothermal spring, Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) baby in a geothermal spring, Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) female holding her baby, Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) female being groomed, Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) baby sucking its toe in a geothermal spring, Jigokudani Monkey Park, Japan

Fiona Rogers / Japanese Macaque (Macaca fuscata) female cuddling her baby, Jigokudani Monkey Park, Japan

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

Cyril Ruoso / Barbary Macaque (Macaca sylvanus) male with infant in snow-covered tree, winter, Middle Atlas Mountains, Morocco

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

XI ZHINONG / Yunnan snub-nosed monkey (Rhinopithecus bieti) sitting in tree, Baima Snow Mountain, Yunnan, China, November

Konrad Wothe / Japanese Macaque (Macaca fuscata) grooming young in snow, Japanese Alps, Japan

Mitsuaki Iwago / Japanese Macaque (Macaca fuscata) mother grooming young, Jigokudani, Japan

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

Stephen Belcher / Japanese Macaque (Macaca fuscata) young embracing at edge of hot spring, Jigokudani, Joshinetsu Kogen National Park, 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 macaques (Macaca fuscata) spread out sitting on small rocks, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) faces looking up, huddling together for warmth on a cold day, Shodoshima, 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 macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

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

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, 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

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

Yukihiro Fukuda / Old Japanese macaque (Macaca fuscata) making patterns on the ground, Shododshima, Japan

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

Yukihiro Fukuda / Two groups of Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaque (Macaca fuscata) searching for nuts with young watching, 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 macaques (Macaca fuscata) warming up by bathing in a hot spring during snowfall, only females and young bathe, Jigokudani, Joshinetsu Kogen NP, Nagano, Japan

Jasper Doest / Japanese Macaque (Macaca fuscata) pair grooming in hot spring, Jigokudani, Japan

Jasper Doest / Japanese Macaque (Macaca fuscata) pair grooming in hot spring, Jigokudani, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} groups walking along snow trail after heavy snow, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} groups walking along snow trail in deep snow, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} mother grooming four-day-old newborn baby, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} four-day-old newborn baby reaches up for mother's nipple, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} young monkey plays with snow ball, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} feeding on seeds in tree in autumn, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} feeding on seeds of the Bittersweet plant, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} young monkeys playing in trees, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} 8-month-old baby in snow, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} groups walking along snow trail after heavy snow, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} feeding on wild cherry tree blossom in spring, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} young monkeys playing in the sunshine in the trees, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} two monkeys grooming and basking in the sun in spring, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} monkey basking in the winter sunshine, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} male grooming female in courtship in Japanese green alder tree {Alnus firma}, autumn, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} 7-month-old monkey bathing in hot springs, examining its hands, water at 40 degrees, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} female with young in autumn woodland, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} two monkeys huddle together to keep warm, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} adult female bathing in hot springs tapping the water surface with hand in play, water at 40 degrees, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} monkey jumping across a river, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} 8-month-old monkey walking through thick snow on hind legs to keep hands warmer, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} group of monkeys bathing in hot springs, water at 40 degrees, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} monkey feeding on the bark of a pine tree in winter, Jigokudani, Nagano, Japan

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} snow crystals on monkey's forehead, Jigokudani, Nagano, Japan

Jasper Doest / Japanese Macaque (Macaca fuscata) with baby, Jigokudani, Japan

Gabriel Rojo / Snow-capped Lanin volcano, Lanin National Park, Argentina, with Monkey puzzle trees (Araucaria araucana) in foreground

Konrad Wothe / Japanese Macaque (Macaca fuscata) baby playing with snowball beside hot springs in Japanese Alps, Japan