Animal of the Week January 11, 2017 — Oh deer! Such monkey business!

If anything is likely to stir Animal of the Week out of hibernation it's unusual animal behaviour* of the kind shown by this week's animal, a particularly randy and misguided Japanese macaque (Macaca fuscata).

Credit: Alexandre Bonnefoy

Reported in the journal Primates, a low-ranking monkey, frustrated by exclusion from females of his own species during the breeding season sought release by trying it on with two separate sika deer (Cervus nippon). The first deer accepted the primate's advances: the monkey mounted the deer without penetr
ation and displayed about 15 sexual movements over 10 seconds before dismounting. [Same.] A second deer did not allow the macaque to mount.

Such interspecific sexual behaviour is rare [outside Wales] and serves no known evolutionary purpose. However, in Japan, macaques and sika deer frequently associate with each other: deer often pick up food discarded by macaques and even eat their faeces. Macaques have previously been observed grooming the deer and occasionally riding them (in an innocent sense). It's possible, that this young male, flush with a hormone surge and excluded from access to female macaques by their preference for higher ranking males confused appropriate behaviour with the other species.

Japanese macaques (also known as snow monkeys) are famed for their love of sitting in pools fed by hot springs during blizzards, they are the most northerly living non-human primates, and they exhibit interesting cultural behaviour such as the washing of food and seasoning potatoes by dipping them in saltwater. Let's not let this aberrant behaviour by one monkey bring down the rep of the whole species.


*Remember this weasel riding a woodpecker from 2015? The glory days of interspecific animal of the week.