Summary. Studies in southern Africa have shown that honeyguides sing at regular sites over many years. The vocal behaviour of forest species of the Guineo-Congolian region remains poorly known, but opportunistic observations over a dozen years have revealed some interesting features: among Indicator and Melignomon species (which sing perched), there is vertical separation between species, from Spotted Honeyguide Indicator maculatus singing low down (in the understorey) to Willcocks's I. willcocksi high in emergents (with special preference for Piptadeniastrum africanum). Each species has a particular timetable for singing, the earliest being Spotted Honeyguide (starting an hour or less after dawn) and the latest Yellow-footed Honeyguide Melignomon eisentrauti (starting some seven hours after dawn). The daily duration of singing varies somewhat between species, the Yellow-footed having apparently the shortest (about two hours). Some species stop singing for 2-3 months each year (Lesser Honeyguide Indicator minor, Willcocks's), or for periods of several weeks (Lyre-tailed Honeyguide Melichneutes robustus, displaying mostly in the long dry season). Spotted Honeyguide may sing all year; we lack information for other species.
Site fidelity from one year to the next has been observed in several species. Within the same species regular song sites seem rather scattered (at least 1 km distant). The Lyre-tailed Honeyguide, however, may have a lekking system, with several individuals aerial-displaying in a restricted area; the special noise produced by this species appears to result from wing as well as tail movements. Almost nothing is known of the behaviour of Cassin's Honeybird Prodotiscus insignis (?aerial display), nor of the singing habits of Least Honeyguide Indicator exilis. Zenker's Honeyguide may behave rather like its congener, the Yellow-footed, with a limited singing period in early afternoon, but more information is necessary to complete the picture for this and other species.