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

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

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

Ingo Arndt / Japanese macaques warming in hot thermal spring {Macaca fuscata} Joshin-etsu NP, Japan

Edwin Giesbers / Barbary macaque (Macaca sylvanus) babies hand holding onto adults fur. Gibraltar Nature Reserve, Gibraltar

Edwin Giesbers / Barbary macaque (Macaca sylvanus) baby sitting with mother, Gibraltar Nature Reserve, Gibraltar, June.

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

Sean Crane / Celebes Black Macaque (Macaca nigra) scratching head, Tangkoko Nature Reserve, Sulawesi, Indonesia

Thomas Marent / Bonnet Macaque (Macaca radiata) pair huddling, Western Ghats, India

Thomas Marent / Bonnet Macaque (Macaca radiata) group huddling, Western Ghats, India

Thomas Marent / Bonnet Macaque (Macaca radiata) trio huddling, Western Ghats, India

Thomas Marent / Lion-tailed Macaque (Macaca silenus) in threat display, Western Ghats, India