[photo 1: A Greater Honeyguide feeds on honeycomb in South Africa. Photo: Nigel J. Dennis/Gallo Images/Corbis. From Audubon.]
[photo 2: A Yao honey-hunter in Mozambique holds a honeyguide bird. Photo: Claire Spottiswoode/University of Cape Town. From New Scientist.]
from New Scientist magazine: Honeyguide birds respond to special calls from human honey-hunters
Excerpt: "People from multiple cultures in Africa have unique sounds [my note: later described in the text as "bird-like whistles" of the Hadza honey-hunters, and "trill-grunts" of the Yao honey-hunters] that they use to communicate with honeyguide birds, and the birds recognise these signals as an invitation to cooperate.
"Greater honeyguides (Indicator indicator) lead humans to bees’ nests so that honey-hunters will break them open. While the humans collect the honey, the birds feast on beeswax and larvae."
The full research article, written by Claire Spottiswoode and Brian Wood, Culturally determined interspecies communication between humans and honeyguides, was published in Volume 382, Issue 6675 of Science.
[By the way, the Honeyguide has a fantastic taxonomic name: "Indicator indicator."]
