Wax digestion by the lesser honeyguide Indicator minor.

Records of the lesser honeyguide feeding on beeswax in the wild are common. However, little is known about the ability of these birds to digest wax. We studied the wax preference, digestive efficiency, retention time and gut structure of the lesser honeyguide in the laboratory. Wax was found to be eaten daily by the lesser honeyguide. Birds ate significantly more new beeswax and foundation wax than old, black beeswax, but required an additional source of protein to maintain body mass. In the absence of other feed, the digestive efficiency for foundation wax was above 90%, with a long transit time of 256 min. Examination of the digestive tract showed no specialisation and no crop. The presence of digestive enzymes, including lipase, in the pancreas and small intestine and very few microbes in the digestive tract of the lesser honeyguide suggests that wax digestion occurs through a biochemical pathway with endogenous avian enzymes.