Academic Reading — Test 54

Reading passage

Across the woodlands and savannahs of sub-Saharan Africa, a remarkable partnership unfolds between people and a small, rather plain bird. The greater honeyguide, a species roughly the size of a sparrow, has long led human foragers to the nests of wild bees. The arrangement is straightforward in its logic. The bird is able to locate hidden colonies of bees but cannot easily break into them, for the nests are usually buried inside hollow trees or crevices and are fiercely defended by stinging insects. Humans, by contrast, can fell a tree, smoke out the bees and prise open the comb, yet they often struggle to find the colonies in the first place. By working together, each obtains something it could not readily secure alone: the people gain honey, while the bird feeds on the beeswax and the bee larvae left behind once the comb has been opened. The interaction begins when a honeyguide approaches a person and produces a distinctive chattering call. It then flies a short distance towards a known bee colony before pausing, calling again and waiting for the human to follow. In this way the bird guides the forager from tree to tree, gradually shortening the distance to the nest. Researchers who have studied the behaviour describe it as genuinely two-way communication, because the people involved also signal to the bird. Among the Yao people of northern Mozambique, foragers use a particular sound, often transcribed as a trilled "brrr-hm", to announce that they are searching for honey and ready to be led. Experiments have shown that honeyguides are considerably more likely to begin guiding, and to keep guiding, when they hear this specialised call rather than other human sounds. The signal therefore appears to function as a deliberate request for cooperation, recognised and acted upon by the bird. What makes the relationship especially unusual is that it is not taught to the birds by humans in any conventional sense. No one captures young honeyguides and trains them; the birds are entirely wild and are raised by other species, since female honeyguides lay their eggs in the nests of unrelated hosts. The guiding behaviour must therefore be acquired largely through the birds' own learning and instinct, refined by their experience of following human foragers to rewards. Intriguingly, the calls that people use to attract honeyguides differ from one region to another. The Yao "brrr-hm" is not the same as the sounds employed by Hadza hunter-gatherers in Tanzania, who tend to use a melodic whistle. This regional variation suggests that the partnership has been shaped by local tradition, with each community developing and passing down its own way of conversing with the birds. The benefits of the cooperation are not trivial. Honey is a rich source of energy and has historically formed an important part of the diet of many foraging communities. Studies among the Hadza have estimated that a substantial proportion of the calories they obtain may, at certain times of year, be derived from honey located with the help of honeyguides. For the bird, the reward is equally valuable: beeswax is difficult to digest, yet honeyguides are among the few animals able to consume it, and a single opened nest can provide a generous meal. Crucially, the bird depends on humans to expose the comb, because without the smoke and tools that people bring, the wax and larvae would remain sealed away behind angry bees. Conservationists worry, however, that this ancient collaboration may be fading. In some areas, the spread of commercial sugar, the decline of traditional foraging and the movement of people into towns have reduced the number of foragers who still seek honey in the old way. Where the human side of the partnership disappears, the birds may gradually lose the opportunity to guide, and the knowledge held by both species could erode. Some researchers have recorded that in regions where guiding is no longer practised, honeyguides appear less inclined to approach people at all. The partnership thus serves as a reminder that certain forms of cooperation between humans and wild animals are not permanent features of nature but living traditions, sustained only so long as both partners continue to play their part. Protecting it may require protecting not only the birds and the bees but also the human practices that once made the three-way exchange possible.