The Greater Honeyguide is the Jekyll and Hyde of birds.
At least, that’s how Claire Spottiswoode tells it. The zoologist from the University of Cambridge has spent the past eight years studying the species’s dark side in the wooded savannas of southern Africa. Minutes after entering the world, Greater Honeyguide chicks turn murderous, using the barbed ends of their beaks to slay their nest mates. But the victims aren’t the young honeyguide's kin—they’re actually the offspring of the nest’s rightful owners, which now have the unfortunate task of raising a brutal brood parasite.
More recently, Spottiswoode has been focused on studying the kinder side of the honeyguide. As adults, the pink-billed birds live up to their name, leading local hunters to wild beehives stashed in the cavities of baobabs and other tall trees. The men then scale the trunks, smash the hives, and make off with the sticky riches, leaving the wax and the calorie-rich larvae within for their partners in crime. (The Greater Honeyguide is one of few avians that can eat and digest wax.) It’s what scientists call a mutualistic interaction, and for the Yao community in Mozambique, where Spottiswoode carried out her newest research, honey plays a vital role in their daily lives.
This unlikely business arrangement between wild birds and people has been chronicled in multiple regions around Africa as early as the 1500s, but it wasn't until Spottiswoode's time with the Yao that the most remarkable part of the relationship was uncovered: The birds and people can communicate. As Spottiswoode recently discovered, the Yao use a resounding brrr-hm—rolling their tongues like a Spaniard before punctuating it with a brassy “humph”—to let the honeyguides know when they’re ready to hunt.
Listen to a Yao hunter call a honeyguide:
In Spottiswoode's experiments, the call was effective in luring in honeyguides 66 percent of the time. And with a bird leading the way, the chances of finding a hive rocketed: Spottiswoode noted that 75 percent of the searches with guides were successful. This level of complex communication is unheard of in nature. In fact, it’s the only known example of targeted two-way signals between people and a free-living species. The next closest scenario might be an unproven partnership involving dolphins and fishing villages in Laguna, Brazil.
While most animals are wired to flee from human presence, the Greater Honeyguide embraces it. But how do the birds learn to work with people? Spottiswoode’s theory is that the behavior is innate. Because the chicks are reared by alternative species (hoopoes, kingfishers, scimitarbills, you name it), they can’t learn this highly unusual behavior from their parents. So, instead, the birds must inherit the knowledge, refining it to match their locale as they mature. In Tanzania, for example, the cue is a whistle; in Zambia, the sound of chopping wood draws them near, she says.
The role of the little bush bird is shrinking, however. As more villagers turn to farming and taming their own hives, they’re leaving the honeyguide to fend for itself. But for the Yao of Mozambique, the alliance remains strong. “ 'Why would we do anything else?' That's what they told me,” Spottiswoode says. The brrr-hm is part of their language, part of their very identity. They learned it from their fathers, and they'll teach it to their sons. After centuries of living alongside nature, the Yao know: In the savanna, you need every last friend you can get.
Honey hunting is not for the faint of heart. Beside the obvious hazard of being stung by an angry horde of bees, there are other dangers lurking in the bush; honey hunters must be wary of being trampled to death by buffalo and elephants, Spottiswoode says. Carrying heavy buckets of honey back to the village is no easy task either.
Something for Everyone
A wild hive offers a rich payoff for guide and hunter. The humans lay claim to the honey, while the birds dig into the larvae-filled comb. Greater Honeyguides are able to process beeswax, possibly thanks to a special combination of enzymes and microbes that live in their digestive tract. Other avians capable of digesting wax include berry-eating songbirds, such as swallows and warblers, and crustacean-loving seabirds, such as petrels and auklets.
The male Greater Honeyguide, or Indicator indicator, is marked by its black beard and striking yellow shoulder patches. Both males and females exhibit symbiotic behavior. Juveniles, meanwhile, look much different, with a honey-lathered chest and prominent eye ring. The contrast is so striking, in fact, that locals consider the young, reclusive honeyguides to be a completely separate species.
Spottiswoode's study on Yao-honeyguide interactions went beyond just basic observation. To measure the effectiveness of the brrr-hm call, she played the hunters' signal on loop while cutting through Greater Honeyguide territory. She then did the same with two other sounds—one human-based and one animal-based—and found that the brrr-hm was by far the best at drawing out the birds. Spottiswoode tested the loudness of the call after it was transmitted through the environment and concluded that it wasn't a factor in attracting the species.
A Tricky Operation
Blowing smoke into the hive helps calm the bees, making it easier (and less chaotic) to crack open the comb. It's a practice also used by Western beekeepers—except the Yao have to figure out how to do it up to 30 feet off the ground. This wooded habitat is not your typical African savanna, but the birds and the villagers have learned to thrive in it. “The trees are tall, and the bees are small,” Spottiswoode says to explain why the hunters rely so heavily on the birds.
The relationship between the Greater Honeyguide and indigenous African communities has been the subject of much scientific inquiry. One study out of northern Tanzania shows that up to 10 percent of the Hadza people's diet can be credited to collaboration with honeyguides. This is despite the fact that some villagers end up burning the wax, leaving little to no reward for their ravenous scouts. Meanwhile, the Boran hunters of Kenya can interpret the birds' flight pattern and calls to pinpoint the distance and direction of the hive.
An Ancient Partnership
The human-honeyguide alliance was first documented in the 1500s, but some experts believe it might stretch back to Homo erectus, which would put it at about 1.9 million years old. Today, the Yao villagers are keeping the tradition alive. Though brrr-hm is their preferred trigger, Spottiswoode says that the type of sound may be largely arbitrary. It's the meaning that matters.
The Yao hunters have unfettered access to the Niassa National Reserve, a protected area that's about the size of Denmark. The sanctuary is managed by the Mozambique government and Wildlife Conservation Society, and plays host to remarkable wilderness, including endemic mammals, ancient trees, and birds such as the African Pitta and Southern Banded Snake-eagle. Spottiswoode points to Niassa as a symbol of human-animal coexistence—which makes it all the more fitting that honeyguides and villagers forage together in its borders.
Like wine, honey tells its own local narrative: It draws its flavor from the land and the animals that make it to form a distinct terroir. The taste varies by nest and is wildly different from the honey you buy at the grocery story. The flavor is severe, Spottiswoode says, almost to the point where it stings your throat.
Correction: The Hadza community is from Tanzania, not Zambia as previously stated in the story.