Honeyguide

Honeyguides make up the bird family Indicatoridae, which includes 16 species in the order Piciformes. They are sometimes called indicator birds or honey birds, though "honey bird" can also refer more specifically to species in the genus *Prodotiscus*. These birds live across the Old World tropics, with most species found in Africa and just two in Asia. Their fame comes from a remarkable habit: one or two species will deliberately guide people to bee colonies, then feed on the larvae and beeswax left after the honey is taken. There have also been reports of honeyguides interacting with honey badgers.

Taxonomically, honeyguides resemble barbets and are brood parasites. Among non-passerine birds, they are unusual in having nine primary feathers. The family belongs to the order Piciformes, which includes eight other families; the number of species in each family follows the list maintained by the International Ornithological Committee.

Most honeyguides have dull greenish-brown plumage, though some—like the yellow-rumped honeyguide of the Himalayas—sport bright yellow patches. All have pale outer tail feathers: white in African species and pale grey in Asian ones. The smallest by body mass is the green-backed honeyguide, averaging 10.2 grams, while the shortest is Cassin's honeyguide, at about 10 centimeters. The heaviest is the lyre-tailed honeyguide (54.2 grams), and the longest is the greater honeyguide (19.5 centimeters).

These birds are among the few that regularly eat wax—mostly beeswax, but also likely the waxy secretions of scale insects for *Prodotiscus* and some smaller *Indicator* and *Melignomon* species. Their diet also includes waxworms (the larvae of the waxmoth *Galleria mellonella*), bees, flying and crawling insects, spiders, and occasional fruit. Many honeyguides join mixed-species feeding flocks.

The guiding behavior that gives honeyguides their name is known in only one or two species, though by extension all members of the family are called honeyguides. The greater honeyguide is the best-studied example; some authorities also claim the scaly-throated honeyguide guides humans, but others disagree. Wild honeyguides respond to specific human calls that initiate the foraging partnership. In northern Tanzania, honeyguides work with Hadza hunter-gatherers, and their help boosts the rate of finding bee colonies by 560%, leading men to nests with significantly more honey than those found alone. The Hadza may not actively reward the birds; instead, they hide or destroy the honeycomb to keep the honeyguide hungry and willing to guide again. Some experts think this mutualism may date back to *Homo erectus*, around 1.9 million years ago.

Whether honeyguides also guide honey badgers is debated. Videos exist, but some have been accused of staging. A 2023 study by the Zoological Society of London found that many interviewees from Hadzabe, Maasai, and mixed-culture communities in Tanzania reported seeing the two species interact and believed they cooperate. The researchers concluded that the interaction likely occurs but is either highly localized or extremely hard to observe—or both. Occasionally, honeyguides lead humans to animals that are not bees, such as snakes; the reason is unclear.

Honeyguides also attack bee nests on their own. Their thick skin offers some protection from stings, but they are not immune and can be killed by bees. To reduce risk, they visit nests in the cool early morning when bees are less active. They also get much of their wax from abandoned nests.

Breeding behavior is known for eight species in *Indicator* and *Prodotiscus*. All are brood parasites, laying one egg per host nest in a series of about five eggs over 5–7 days. Most target hole-nesting birds like barbets and woodpeckers, but *Prodotiscus* species parasitize cup-nesters such as white-eyes and warblers. Honeyguide chicks have needle-sharp hooks on their beaks and physically eject host chicks or puncture host eggs and kill nestlings. African honeyguides sometimes lay eggs in the underground nests of other bee-eating birds. The mother ensures her chick hatches first by internally incubating the egg for an extra day before laying it, giving it a developmental head start over the host's offspring.