From the Mozambican, bush comes a fascinating example of symbiosis – the relationship between the honeyguide bird and humans.
Honey has long been a delicacy to humans and animals alike. Nutrient-rich and loaded with calories, honey is delicious and healthy. The problem for both humans and animals? Finding and extracting honey from beehives.
In Mozambique, human honey-collectors use a vocal call to recruit the assistance of the aptly-named honeyguide bird. This species then flies from tree to tree, indicating the presence of beehives, which would otherwise be difficult to find. While fascinating, this is nothing new; humans have learned to train and utilize the abilities of several animal varieties, from carrier pigeons to the common dog.
What makes this relationship remarkable is that this relationship goes both ways – the honeyguide bird has been found to recruit humans as well, giving a unique call to attract our attention.
The greater honeyguide bird is not actually interested in honey. It eats wax and uses pieces of the bee’s hive for nesting material. Humans are useful to the bird because of our ability to subdue the bees with smoke, and to split the hives open. Dr. Claire Spottiswoode, an evolutionary biologist at the University of Cambridge and the University of Cape Town, has been studying this phenomenon with her colleagues.
“What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years,” says Spottiswoode.
Her team found that in attracting the honeyguide, human honey-collectors produce a loud trill with their mouths followed but an abrupt grunt, a call which Spottiswoode dubbed the “brrr-hm.”
“The traditional ‘brrr-hm’ call,” Spottiswoode said, “Increased the probability of being guided by a honeyguide from 33% to 66%, and the overall probability of being shown a bees’ nest from 16% to 54% compared to the control sounds. In other words, the ‘brrr-hm’ call more than tripled the chances of a successful interaction, yielding honey for the humans and wax for the bird.”
Even more fascinating? This is no recent development. The partnership between man and honeyguide was recorded as early as 1588, when a Portuguese missionary in what is now Mozambique observed a small brown bird slipping into his church to nibble his wax candles. Intrigued, he began studying this bird and found that it led humans to beehives by flying from tree to tree. Once the nest was located, the men harvested the honey and the bird fed on the wax.
“The world is a richer place for wildernesses like [the one in Mozambique],” Spottiswoode said, “where this astonishing example of human-animal cooperation still thrives.”