Woodhoopoes

(Phoeniculidae)

Class Aves

Order Coraciiformes

Suborder Bucerotes

Family Phoeniculidae

Thumbnail description
Medium-sized to small birds with long, slender, decurved bill; plumage mainly black, with green or purple gloss; broad, rounded wings and long, graduated tail

Size
8–15 in (20–38 cm); 0.6–3.5 oz (18–99 g)

Number of genera, species
2 genera; 6 species

Habitat
Forest, woodland, savanna

Conservation status
Not threatened

Distribution
Sub-Saharan Africa

Evolution and systematics

The fossilized remains of woodhoopoe-like birds have been found from Eocene and more recent Miocene deposits in Europe, but modern woodhoopoes are now confined to Africa. Woodhoopoes occur in two main forms, based on studies of their anatomy, DNA-DNA hybridization, and nuclear DNA. The two groups are usually separated as subfamilies, sometimes even as families, the true woodhoopoes, Phoeniculinae (genus Phoeniculus), which live in groups and breed cooperatively, and the smaller scimitarbills, Rhinopomastinae (genus Rhinopomastus), which live and breed only as pairs. The separation occurred about 10.2 million years ago, based on estimation from a molecular clock.

Woodhoopoes are most closely related to the more widespread hoopoe (Upupa epops), family Upupidae, with which they share a unique stirrup-like structure of the inner ear bone. The hoopoe feeds mainly while walking on the ground, whereas woodhoopoes feed mainly by hopping about on tree branches. Molecular and anatomical evidence suggests that woodhoopoes and hoopoes are close relatives of hornbills (family Bucerotidae), which lack the stirrup-like stapes but have their own unique neck vertebrae, and also have terrestrial and arboreal members. Still more distant relatives are other members of the order Coraciiformes.

Three species of woodhoopoe are recognized in each sub-family. All species can be divided further into clearly recognizable subspecies that, in the widespread and variable green woodhoopoe (P. purpureus), are sometimes even treated as separate species, the violet woodhoopoe (P. damarensis) and the black-billed woodhoopoe (P. somaliensis).

Physical characteristics

Medium-sized to small birds, mainly black, with a green or purple gloss to the plumage and a dark brown iris. In four species there are patches of white across the wing and on the tips of tail feathers. The broad, rounded wings and long, graduated tail allow buoyant, dexterous and, at times, rapid flight. The bill and feet are black in juveniles of all species, but the bill becomes orange-red in adults of three species, as do the feet in two species. The bill is long, thin, and decurved, especially in two species of scimitarbill, as the name implies. The long toes, short legs, and hooked claws are thick and strong.

Distribution

Throughout sub-Saharan Africa, with at least one and in some areas up to three species present as in northeast Africa. Absent from treeless desert and steppes, and only two species occur in the more northern areas of tropical forest. The green woodhoopoe is the most widespread member of the subfamily Phoeniculinae, while the common scimitarbill (R. cyanomelas) and black woodhoopoe (R. aterrimus) are the most widespread members of the subfamily Rhinopomastinae.

Habitat

Woodhoopoes require sufficient tree holes to roost and nest, and adequate areas of bark and twig foraging surfaces to conceal their invertebrate food. Suitable habitat ranges from scattered trees within arid steppes, to the rainforest canopy. Two species, the forest woodhoopoe (P. castaneiceps) and the white-headed hoopoe (P. bollei), are confined to forest. The widespread green woodhoopoe, black woodhoopoe, and the common scimitarbill occupy a range of woodland and savanna types, while the Abyssinian scimitarbill (R. minor) is confined to more arid savanna.

Behavior

All woodhoopoes appear to be sedentary and territorial. True woodhoopoes are gregarious, usually living in groups of six to eight birds, while scimitarbills live only as pairs. All species appear to roost in a tree hole, a behavior that conserves energy in the group-roosting green woodhoopoe. True woodhoopoes are noisy and each group defends its territory with loud cackling calls and exaggerated bowing and flagging displays. Scimitarbills are much quieter and usually advertise their occupancy only with melodious hooting.

Feeding ecology and diet

The woodhoopoe diet is mainly insects, arachnids, and their larvae, with a few fruits, other invertebrates, or small vertebrates when available. Prey is located mainly by probing into crevices and cracks, or levering off bark, on the trunks and limbs of trees. Strong feet allow woodhoopoes to hunt at all angles, including hanging upside down. Larger species tend to search on larger branches, species with thicker, straighter bills dig and lever more often, while the small scimitarbills probe into the finest holes on the smallest twigs. Some species will also feed on the ground or hawk flying insects, but no species needs to drink regularly since they obtain moisture from their prey.

Reproductive biology

All woodhoopoes nest in a tree hole. Most cavities are natural, but old nest holes excavated by barbets and woodpeckers are also occupied, and they will rarely use a hole in the ground or a building. Where known, pairs are monogamous, and the male and adult group members courtship-feed the breeding female before egg-laying and continue to provision her and later the chicks during nesting. The female lays and incubates the clutch of two to five gray or blue-green eggs with their oval, pitted shells. She broods the young chicks after hatching, but later leaves them and joins the male or group to help deliver food. The nestlings initially retain the growing feathers within their sheaths, giving them a prickly appearance. Juveniles stay with the parents for several months after fledging, especially in gregarious species where they become helpers. The breeding biology of forest species and those in remote areas is virtually unknown. Woodhoopoes, especially chicks, have a musty odor derived from the oil of the preen gland. When combined with a hissing, head-waving, threat display and excretion of copious smelly feces, this deters predators at the nest or roost. In the green woodhoopoe, the odor is the chemical product of a symbiotic Enterococcus bacterium, unique to woodhoopoes and only discovered in 2001. In addition to repelling potential predators, it also has a hygienic, antibacterial effect.

Conservation status

No species of woodhoopoe is threatened. Locally, in western Kenya, Uganda, and South Africa, numbers have been reduced by collection of timber for fuel or building material.

Significance to humans

Woodhoopoes have no particular significance to humans. Onomatopoeic local names recognize the noisy Phoeniculus species and the smelly and aggressive chicks.

Species accounts

List of Species

Green woodhoopoe

Phoeniculus purpureus

subfamily

Phoeniculinae

taxonomy

Promperops purpureus J. F. Miller, 1784, Cape Province, South Africa. Eleven subspecies.

other common names

English: Red-billed woodhoopoe; French: Irrisor moqueur; German: Baumhopf; Spanish: Abubilla-arbórea Verde.

physical characteristics

13–15 in (32–37 cm), 2–3.5 oz (54–99 g). Largest, most widespread woodhoopoe. Black plumage with variable green and purple gloss, white spots on flight feathers and tip of tail, red bill and feet (bill black in some populations), male bill length and mass 18–20% more than female.

distribution

Sub-Saharan Africa. P. p. guineensis: northern Senegal, Mail, eastern to northern Ghana; P. p. senegalensis: southern Senegal east to Ghana; P. p. niloticus: northeast Zaire, Sudan to western Ethiopia; P. p. abyssinicus: northern Ethiopia and Eritrea; P. p. neglectus: central Ethiopia; P. p. somaliensis: southeast Ethiopia, Somalia to northeast Kenya; P. p. marwitzi: southern Somalia, Kenya, eastern Uganda, south to eastern South Africa; P. p. granti: southern Ethiopia and Kenya; P. p. damarensis: southwest Angola and northwest Namibia; P. p. angolensis: eastern Angola and eastern Namibia, east to western

Zambia and western Zimbabwe; P. p. purpureus: southeastern South Africa.

habitat

Open woodland, savanna, and dry mixed scrub with a few larger trees, to over 6,560 ft (2,000 m) above sea level.

behavior

Group-living, advertise territory with loud cackling calls and bowing displays. Often allopreen and exchange food in social behavior.

feeding ecology and diet

Probe cracks or bark on tree trunks and limbs for invertebrate food such as caterpillars, beetle larvae, and spiders. Sometimes dig in animal dung on the ground, hawk insects in flight, or pirate food from nestlings of other species.

reproductive biology

Breed cooperatively, alpha pair assisted by adult and juvenile helpers. Nest in tree hole, or rarely in ground or building, usually during late summer wet season. Lay two to five eggs, incubation 17–18 days, nestling period about 30 days, female and chicks fed by group. Sometimes parasitized by greater honeyguide (Indicator indicator).

conservation status

Not threatened. Widespread and common throughout its range, including in a number of large national parks.

significance to humans

None known, but often found in gardens and parks.

Common scimitarbill

Rhinopomastus cyanomelas

subfamily

Rhinopomastinae

taxonomy

Falcinellus cyanomelas Vieillot, 1819, Orange River, northwestern Cape, South Africa. Two subspecies.

other common names

English: Scimitar-billed woodhoopoe, greater/black scimitar-bill; French: Irrisor namaquois; German: Sichelhopf; Spanish: Abubilla-arbórea Cimitarra.

physical characteristics

10–12 in (26–30 cm), 0.8–1.3 oz (24–38 g). Small, plumage black with purple gloss and white spots on primaries and tips of outer tail feathers. Black bill and feet, strongly decurved bill slightly larger in male.

distribution

Southeast and southern Africa. R. c. schalowi: southern Uganda, southwest and central Kenya and southern Somalia south to Zambia, and northeast South Africa; R. c. cyanomelas: southwest Angola and Namibia, east to northern South Africa.

habitat

Open woodland, savanna, and dry thorn-scrub with a few larger trees, to over 6,560 ft (2,000 m) above sea level.

behavior

Solitary, in pairs, or in family groups after breeding,. Roosts in tree hole or, if unavailable, clings to trunk. Territorial call a mournful three to five hooting notes.

feeding ecology and diet

Mainly insect larvae and spiders, plus some other small insects, fruit, buds, and nectar, taken among finer branches and twigs. Probe at all angles, often inserting only the slender lower mandible. Join mixed species foraging flocks during dry winter months.

reproductive biology

Breed as territorial pair. Nest in tree hole, usually during early summer wet season. Lay two to four eggs, white or slightlytinted in color, incubation 17–18 days, female and chicks fed at nest by male, nestling period about 24 days during which female emerges to help male. Chicks produce smelly preen oils and feces in defense.

conservation status

Not threatened. Widespread and common throughout its range, including in a number of large national parks.

significance to humans

None known.

Resources

Books

Law-Brown, Janette. Chemical Defense in the Red-billed Woodhoopoe Phoneiculus purpureus. Unpublished M.Sc. thesis. Cape Town: University of Cape Town, 2001.

Ligon, J.D. "Family Phoeniculidae (Woodhoopoes)." In Handbook of Birds of the World. Vol. 6, Mousebirds to Hornbills, edited by J. del Hoyo, A. Elliott, and J. Sargatal. Barcelona: Lynx Edicions, 2001.

Sibley, C.G., and J.E. Ahlquist. Phylogeny and Classification of Birds: A Study in Molecular Evolution. New Haven and London: Yale University Press, 1990.

Stuart, Chris, and Tilde Stuart. "Wood-hoopoes." In Birds of Africa: From Seabirds to Seed-eaters. Cambridge, MA: MIT Press, 1999.

Periodicals

Burton, P.K.J. "Anatomy and Evolution of the Feeding Apparatus in the Avian Order Coraciiformes and Piciformes." Bulletin of the British Museum (Natural History) 47, no. 6 (1984): 1–113.

Johansson, U.S., T.J. Parsons, M. Irestedt, and P.G.P. Ericson. "Clades Within the 'Higher Land Birds,' Evaluated by Nuclear DNA Sequences." Journal of Zoological Systematics and Evolutionary Research 39 (2001): 37–51.

Ligon, J.D., C. Carey, and S.H. Ligon. "Cavity Roosting, Philopatry, and Cooperative Breeding in the Green Woodhoopoe May Reflect a Physiological Trait." Auk 105(1988): 123–7.

Plessis, M.A. du, and J.B. Williams. "Communal Cavity Roosting in Green Woodhoopoes: Consequences for Energy Expenditure and the Seasonal Pattern of Mortality." Auk 111 (1994): 292–9.

Steyn, P. "The Breeding Biology of the Scimitarbilled Woodhoopoe." Ostrich 70, no. 3&4 (1999): 173–8.

Wanless, Ross. "Red-billed Woodhoopoes Go on the Defensive. Preening Power." Africa Birds & Birding 6, no. 1(2001): 55–59.

Organizations

Woodhoopoe Research Project, FitzPatrick Institute of African Ornithology, University of Cape Town. P.O. Rondebosch, Cape Town, Western Cape 7700 South Africa. Phone: +27 (0)21 650-3290. Fax: +27-21-650-3295. E-mail: [email protected] Web site: <http://www.fitztitute.uct.ac.za>

Other

Coraciiformes Taxon Advisory Group. <http://www.coraciiformestag.com>.

Alan C. Kemp, PhD