Pachycephalidae – Whistlers & Allies

Pachycephalidae is a family of passerine species that includes the whistlers, shrikethrushes, and three of the pitohuis. It is part of the ancient Australo-Papuan radiation of passerines. Its members range from small to medium in size, and occupy most of Australasia. Australia and New Guinea are the centre of their diversity, and in the case of the whistlers, the South Pacific islands as far as Tonga and Samoa and parts of Asia as far as India. The exact delimitation of boundaries of the family is uncertain, and one species, the Golden Whistler, has been the subject of intense taxonomic scrutiny in recent years, with multiple subspecies and species-level revisions.

They are birds of forests and wooded areas. Most species inhabit rainforest, particularly in the Asian and Papuan parts of their range, but Australian species inhabit a wider range of habitats including woodlands, arid scrubland and mangrove forests. Some species are restricted to a particular ecosystem, whereas others are more catholic and will inhabit a range of habitat types.

Rusty Pitohui Pseudorectes ferrugineus

Variable Shrikethrush Colluricincla megarhyncha fortis

The whistlers are stout birds with strong bills, and the group was once known as the ‘thickheads’ due to the large rounded heads of many species. Indeed, the family name Pachycephalidae, translates as such. Their plumage is rufous, brown, or grey-green in the majority of species. Nevertheless, a few species, particularly the Golden Whistler and its close relatives, have bright plumage. One of the more unusual traits of this family is found in the feathers of some of the pitohuis, which have toxins. These toxins are probably a deterrent to parasites and may also serve to dissuade predators from taking the birds.

They are insectivorous, picking insects and other invertebrates off leaves, branches, or leaf litter. While insects make up the majority of the diet they will also feed on spiders, worms, centipedes, snails, and small crabs; larger species will also tackle small vertebrates such as frogs, geckos and baby birds. They are generally sedate foragers and do not engage in hawking to obtain prey, instead being gleaners and probers. Only a few species migrate, most remaining resident in their tropical environment.

Regent Whistler Pachycephala schlegelii

White-vented Whistler Pachycephala homeyeri

Little is known about the breeding biology of most of the family; what is known generally comes from a small number of Australian species. Those that are known are monogamous and generally nest as simple pairs, although breeding groups have been recorded in some species.

Lorentz’s Whistler Pachycephala lorentzi

Yellow-bellied Whistler Pachycephala philippinensis

For example, the Rufous Whistler Pachycephala rufiventris, Breeds in monogamous pairs, both males and females incubate their eggs and care for their young. The period of incubation is about 13 days on average. The female alone constructs the nest, which usually consists of a combination of twigs, vines, grass and other matter formed in a cup-like shape and attached to a tree branch using strands from spider webs. The breeding season for Rufous Whistlers is between the months of July and February.

White-bellied Whistler Pachycephala leucogastra

Black-headed Whistler Pachycephala monacha

Several species belonging to this family are outstanding songsters: the whistlers produce an astonishing volume for their size, and the lyrebirds aside, the Grey Shrikethrush is often regarded as the finest, most inventive songbird of them all. Their haunting, strong, and ethereal whistles making the dawn choruses in their home region as moving, and recognisable, as those anywhere.