African Broadbill at Bwindi: The Spectacular Spinning Display Flight
The African broadbill (Smithornis capensis) is an inconspicuous forest bird in Uganda's western forests — 13 centimetres of brown-and-streaked plumage that sits quietly in the forest mid-stratum for most of the day — until it begins its display. The male broadbill's display flight is one of the most bizarre and entertaining avian behaviours in Uganda: the bird rises from its perch and spirals rapidly upward in a tight circular loop while spreading its wings at the top of each arc, creating a mechanical purring sound with the feathers rather than with its voice. The bird completes 3 to 8 of these circular spirals before returning to the same perch it started from. The whole display lasts 2 to 5 seconds. And then it does it again, up to 30 times in a morning session.
The Mechanical Sound
The purring sound produced by the African broadbill in display is not vocal — it is produced by the outermost primary feathers, which are modified to produce a buzzing mechanical sound when moved through the air at high speed during the display loop. This non-vocal sound production (called feather sound production) carries 30 to 50 metres in closed forest and is the primary way to locate the species — once the purring whirr is heard, following it to the source is straightforward, as the displaying male returns to the same perch repeatedly.
Where to Find African Broadbill
Bwindi — Buhoma sector: The species is present at the forest edge and interior at Buhoma, most reliably along the lower Munyaga River trail where dense undergrowth and canopy provide the conditions the species prefers. Displaying males are heard and seen from March to June (primary breeding season) when display activity is most frequent.
Kibale Forest: Also present in the Kanyanchu trail area. Less frequently encountered than at Bwindi but present year-round.
Identification at Rest
At rest, the African broadbill is a plain, streaked bird — easy to overlook. The broad flat bill (for which the family is named) is the best identification feature: wider than tall at the base, with a slightly hooked tip, yellow-orange at the base. The overall brown-streaked plumage with white supercilium makes it resemble several forest warblers at first glance, but the bill shape and hunched horizontal sitting posture on a horizontal branch are distinctive to experienced observers.
Feather Sound Production: The Mechanics of the Display
The mechanical sound production of the African broadbill display is achieved through a modification of the outermost primary feathers. These feathers are narrower than normal and stiffened at the tip — when the bird performs the circular loop flight and reaches maximum wing speed at the peak of each arc, the air flowing over these modified feathers generates a buzzing vibration. The frequency is approximately 200 to 300 Hz — a low purring rather than a high whistle — and the sound is entirely mechanical, not produced by the syrinx (the avian vocal organ). This places the broadbill alongside manakins, snipe and hummingbirds in the select group of birds that have evolved secondary, non-vocal sound-production mechanisms for display purposes.
Ecology and Nest
The African broadbill is an insectivore of the forest mid-stratum. It forages by watching from a horizontal branch at 2 to 6 metres height and making short aerial sallies to catch flying insects, returning to the same or adjacent perch — standard flycatcher hunting behaviour. The broad flat bill (the diagnostic feature of the broadbill family Smithornithidae) is an adaptation for aerial insect capture rather than for any plant-food manipulation.
The nest is a pear-shaped pendant structure, suspended from a thin drooping branch tip at 2 to 5 metres height, constructed from moss, plant fibres and spider web silk. The nest's exterior is camouflaged with lichens and pieces of bark, giving it the appearance of a natural accumulation of dead material on the branch — very difficult to spot from below unless the nest entrance is identified by observing the adult entering or leaving.
Other Uganda Sites and the Breeding Season
African broadbill at Kibale Forest is present year-round in the Kanyanchu trail area and the forest between the park gate and the visitor centre. Display activity at Kibale peaks March to May coinciding with the long rains — the display is used for territory maintenance and mate attraction simultaneously. Budongo Forest also holds the species and the Royal Mile trail produces displaying males in the same March to June window. All three Uganda sites (Bwindi, Kibale, Budongo) are most productive for broadbill display in the first 3 hours of morning from 6:00 to 9:00am.
Frequently Asked Questions: African Broadbill Bwindi
How easy is the display to see?
The display sound is easy to locate by ear; the visual display loop itself is very fast (2 to 5 seconds per loop) and requires focused attention. Most birders who hear the purring and stand quietly at the perch site see the display within 5 minutes of arrival.
When is the display most frequent?
March to June at Bwindi and Kibale, peaking in April and May. Males display from dawn to approximately 9:30am with decreasing frequency through the morning. By midday, displaying has typically ceased and the bird returns to quiet perching.
Can I photograph the display?
Yes, but it is one of the most technically demanding subjects in Uganda bird photography. The display loop is 2 to 5 seconds long and the bird is moving rapidly through partial shade. Set ISO 1600 or higher, 1/1000 second minimum shutter speed, and use burst mode. The clearest shots come when the bird reaches the top of its loop arc briefly before beginning the descent — this is the longest stationary moment in the display, approximately 0.3 to 0.5 seconds.
Is the African broadbill related to the African green broadbill at Bwindi?
No — despite sharing the name "broadbill", the African broadbill (Smithornis capensis) and the African green broadbill (Pseudocalyptomena graueri) are in different families. The African green broadbill is in the family Calyptomenidae; the African broadbill is in Smithornithidae. Both occur at Bwindi but in different habitat layers — the African green broadbill is in the dense Bwindi canopy at 1,600 to 2,200 metres, while the African broadbill is in the forest mid-stratum undergrowth at lower altitudes. They can both be targeted on the same Bwindi day at Buhoma.
Does the African broadbill occur at Murchison Falls or Queen Elizabeth?
No — it is strictly a closed-canopy forest species. Murchison Falls and Queen Elizabeth are savannah and woodland parks where no closed-canopy forest species occur. The African broadbill is found only in the western forest parks and reserves: Kibale, Bwindi, Budongo, Semuliki and the Kasyoha-Kitomi Forest.
How does the broadbill family relate to other bird families?
Smithornithidae (the African broadbill family) is now considered a small, isolated family with just three species (African broadbill, Rufous-sided broadbill and Grey-headed broadbill) distributed in African forest from West Africa to Uganda. Recent molecular studies have clarified that the African broadbills are not closely related to the Asian broadbill families (Eurylaimidae, Calyptomenidae) despite the similar bill shape — the resemblance is convergent evolution driven by the same aerial insect-catching foraging technique.
Contact Shoebill Uganda Bird Tours to see the African broadbill display at Bwindi or Kibale — one of Uganda's most entertaining and unusual bird behaviours.