Our new paper investigating foraging strategies in greater honeyguides is out now, published in Proceedings of the Royal Society B.
After guiding a honey-hunter to a bees’ nest, the honeyguide is gratefully rewarded with a piece of beeswax, which it eats. There is usually enough beeswax to feed many honeyguides, and we often observe up to ten birds feeding in turn. Nine of these birds didn’t help the honey-hunter, so why should they make the effort to locate and guide a honey-hunter, when they can simply wait for another bird to do so and scavenge a free meal? We wanted to answer this question, and improve our understanding of this type of ‘producer-scrounger’ system more generally, by studying the honeyguides of Niassa Special Reserve in Northern Mozambique.
We used a ringed population of honeyguides to ask whether honeyguides consistently guide or scrounge, which types of honeyguide adopt each tactic, and quantify the tactic pay-offs. Our results revealed that honeyguides flexibly switch between tactics in an opportunistic way. Larger honeyguides typically scrounged, likely because they were able to bully other birds to gain access to the beeswax. The smallest females almost never guided. We suspect this may be related to the genetic matrilines in this species, which influence body size. The smallest females are from the lineage that parasitizes ground-nesting species, and these females may therefore have been preoccupied with breeding during our fieldwork. This idea requires further research – so watch this space! We also found that guiding provided the biggest pay-offs, by increasing a honeyguide’s access to the best pieces of beeswax, and reducing the chances of it being deprived by a greedy honey badger.
Overall, the details of the honeyguide producer-scrounger system we uncovered are likely to strengthen the human-honeyguide mutualism, for two reasons. First, tactic-switching means that any honeyguide should be able to guide, and second, the greater pay-offs of guiding means that they should be incentivised to do so whenever the opportunity arises