The greater honeyguide bird has evolved to seek out and cooperate with humans to help them find honey, scientists have reported this week.
Humans bring the muscle and the tools, including fire, to smoke out the bees, but the birds know where they are and wants wax as payment!
These birds, which are natives to Africa and parts of Asia and the latin for which is Indicator indicator, were first described centuries ago. A Portuguese missionary documented in 1588 that the animals would fly into his church to steal candle wax but also appeared to lead locals to bees' nests.
The birds are well known to natives today, who call to them to enlist their help on foraging expeditions. The birds flit from tree to tree making unusual calls distinct from their normal songs to attract attention and, in so doing, draw honey-seekers to hidden nests up to a kilometre away.
Once the human heavyweight counterparts have opened the nests, subdued the bees and taken the honey, the birds then help themselves to the wax from left-over honeycombs.
That much was known, but what isn't clear is why the birds do this. Does it constitute a learned behaviour, or an evolved innate trait?
To find out, University of Cape Town researcher Claire Spottiswoode carried out a field trial in Mozambique. Accompanying local human honey-gatherers, she played normal human speech, songs of other birds, or the specific call that the locals in the region use to summon the birds.
The specific call was successful in recruiting a honeyguide bird nearly 70% of the time, compared with only about a 30% success rate for the other two sounds. And when the birds were successfully recruited, bees' nests and honey were located in over 54% of expeditions compared with only a 17% success rate without the birds.
Unusually, honeyguides are brood parasites, like cuckoos, so they are not reared by their natural parents. Their ability to locate bees' nests, Spottiswoode speculates in her paper describing the work in Science, is likely to be a genetically hard-wired trait. But, in the same way that the locals say that they learn to speak to the birds from their fathers, the honeyguides' response to humans is probably learned when individuals mix at the sites of successful honey-foraging.