Family PTILONORHYNCHIDAE G.R. Gray, 1841

Museums

Regional Maps

• Ptilonorhynchidae Gray, G.R. 1841. A List of the Genera of Birds, with their synonyms and an indication of the typical species of each genus. London : R. & J. Taylor xii 115 pp. [Date published Sep 1841].

  Type genus:

   Ptilonorhynchus Kuhl, 1820.

Introduction

Ptylonorhynchids number 18 species in eight genera, distributed throughout Australia and New Guinea, excluding Tasmania. Australia has 14 ultrataxa, representing nine species in six genera. Many are endemic to Australia supporting the thesis of an Australian centre of biodiversity. Within the group are two distinct forms: the bowerbirds characterised by the elaborate bower structures built by the males as courting and display arenas; and the catbirds, which are generally non-bower building although some construct and use display areas. All are distinguished mimics using the calls and sounds of others in their displays.

Most male bowerbirds construct stick bowers shaped like a tunnel with sticks with similar materials forming a display platform. Often the interior of the tunnel is painted using saliva and charcoal or other materials as the base. These bowers are decorated with flowers, berries and fruits or often bleached bones, snail shells, and glass and other man made objects. One species, the Golden Bowerbird (Prionodura newtoniana) constructs a different bower, the male selects a horizontal branch low to the ground and arranges vines and twigs forming a large wall at each end often joining underneath the perch; this bower is decorated with flowers and lichens. The Tooth-billed Catbird (Scenopoeetes dentirostris) clears an area, beneath his singing perch, of all vegetation leaving a bare earthen arena. Rainforest tree leaves that are scattered over the arena decorate this arena.

Bowerbirds and catbirds are both terrestrial and arboreal. Bowerbirds inhabit broadleaf thickets and scrublands, woodlands, human habitation, mulga, and forests. Catbirds differ in being restricted to rainforests and adjoining wet sclerophyll forest. They spend considerable time gleaning and probing for invertebrates and taking fruits. Small loose family groups will often congregate in large foraging parties, especially in winter, while migrating, or about fruiting trees. Ptylonorhynchids are regarded as sedentary but large migrational movements have been detected; such movement is difficult to follow as moving birds are replaced by others coming in from other regions and giving an incorrect impression of a constant presence.

Male plumages of bowerbirds are variable; those frequenting wet sclerophyll and rainforest habitats differ from the plainer-plumaged females by having bright colourful plumage, developed after many years of having plumage similar to the female. Some males in the genus Chlamydera have plumage that is similar to that of the females, except they have a brilliant pinkish-purple nape patch which is often hidden unless used in display.

Nests, differing considerably from the elaborate bower structure, are placed in thick foliage well above ground. The nest is a cup, formed from vine tendrils and fine sticks and lined with finer materials and bark. Generally two eggs are laid. Two forms of egg are laid: buffy-cream eggs, heavily spotted, dotted or streaked by olive-brown to blackish-brown by Sericulus, Ptilonorhynchus and Chlamydera; and cream-white, but unmarked, eggs by Ailuroedus, Scenopoeetes and Prionodura.

Diagnosis

'Bowerbirds have a distinctive long, oval apterium (bare space) in the middle of the saddle of the dorsal feather tract. Except in the catbirds (Ailuroedus) with their reduced postorbital and zygomatic processes, temporal fossae are large and well defined. Palates too, are not openly aperturate fronting a bulbous cranium. But also have a much broadened and evenly thickened palatine shelf with an out-curved or -angled outer margin; the vomer is truncate-emarginate at the tip, except in Chlamydera. In the quadrates, the orbital process is attenuately narrowed and the posterior condyle missing; and the ectethmoids are often small, thin, narrowly winged and separated from the frontal bone by enlarged lachrymals which are flared dorsolaterally up around the outside of the frontal. The enlarged lachrymal in bowerbirds is unique in song-birds, its development paralleled only in lyrebirds (Stonor 1937; Bock 1963).'

Diagnosis References

Bock, W.J. 1963. Relationships between the birds of paradise and the bower-birds. Condor 65: 95-125

Schodde, R. & Mason, I.J. 1999. The Directory of Australian Birds : Passerines. A Taxonomic and Zoogeographic Atlas of the Biodiversity of Birds in Australia and its Territories. Collingwood, Australia : CSIRO Publishing x 851 pp.

Stonor, C.R. 1937. On the systematic position of the Ptilonorhynchidae. Proceedings of the Zoological Society of London 107B: 475-490

History of changes