They say that imitation is the sincerest form of flattery and it appears that capuchins believe it too. These very sociable monkeys gravitate towards humans that mimic their actions, spending more time in their company and even preferring to trade with them.
Annika Paukner, who studied this monkey business, thinks that imitation is a type of social glue that binds groups of monkeys together. It says, “We are alike,” and in doing so, it lays the foundation for acts of selflessness by providing a means for two individuals to form an empathic connection.
Certainly, imitation is very much a part and parcel of human life. Every day, we mimic the gestures and mannerisms of people we meet. We sit in the same way, twirl our hair, shift our accents or scratch the same spot. This “chameleon effect” is almost always unconscious and while subtle, it can have a big impact on our social success. Others like us more if our behaviour matches their own, and we in turn put more unconscious effort into imitation if we want someone to like us or if sense that we’re being ostracised.
Paukner and other biologists suggest that these unconscious acts of imitation are adaptations to a social life and she wanted to see if imitation can also strengthen relationships in other sociable primates. Capuchins certainly fit the bill. Paukner allowed monkeys to play with a rubber ball while experimenters either matched their movements with their own balls or played in a different way. The animals spent significantly more time looking at the imitating human than the other one.
The animal world is full of harmless liars, who mimic species more dangerous than themselves in order to avoid the attention of predators. But none do it quite like the dark-footed ant-spider Myrmarachne melanotarsa.
As its name suggests, this small species of jumping spider, discovered just nine years ago, impersonates ants. In itself, that’s nothing special – ants are so aggressive that many predators give them a wide berth and lots of species do well by imitating them. The list includes over 100 spiders but among them, M.melanotarsa‘s impression is unusually strong. It doesn’t just mimic the bodies of ants, but their large groups too.
Unlike all of its relatives, the spider lives in silken apartment complexes, consisting of many individual nests connected by silk. These blocks can house hundreds of individuals and while moving about them, the spiders usually travel in groups. Now, Ximena Nelson and Robert Jackson from the University of Canterbury have found evidence that this social streak is all part of the spiders’ deception.
Ants are among the most successful of living things. Their nests are well-defended fortresses, coordinated through complex communication systems involving touch and chemical signals. These strongholds are stocked with food and secure from the outside world, so they make a tempting prospect for any burglars that manage to break in.
One species of butterfly – the mountain alcon blue (Maculinea rebeli) – is just one such master felon. Somehow, it manipulates the workers into carrying it inside the nest, feeding it and caring for it. The caterpillar does so little for itself that it packs on 98% of its eventual adult weight in the company of ants. How does it do it?
Partly, the caterpillar secretes chemicals that imitate those found on ant larvae, and it mimics their actions too. But that can’t be the only explanation for ant workers will actually rescue alcon blue caterpillars over their colony’s genuine larvae. And if food is short, they will even kill their own young to feed the parasitic impostors. In the entire colony, only one individual is treated with as much respect as the caterpillars – the queen.
Now, Francesca Barbero from the University of Torino has found out how the alcon blues manage to get the royal treatment – they “sing” in the style of queens, producing uncanny cover versions using instruments built into their bodies.