Product Code Database
The bristlebirds are a family of passerine , Dasyornithidae. There are three species in one genus, Dasyornis. The family is endemism to the south-east coastal regions and south-west corner of Australia, but each species occupies a mostly disjunct and restricted range of its own.Del Hoyo, J.; Elliot, A. & Christie D. (editors). (2006). Handbook of the Birds of the World. Volume 12: Picathartes to Tits and Chickadees. Lynx Edicions. They are primarily ground-scampering, though they can fly short distances, and it is primarily in dense coastal scrub that they forage on foot for their food. They are also more often heard than seen, having sweet and resonant calls with a metallica character; two of the three species are endangered.
The family now comprises three species: Eastern, Rufous and Western bristlebirds. At least three subspecies have been identified in the family: the critically endangered northern subspecies monoides of the Eastern bristlebird; the likely extinct dune-dwelling litoralis of the Rufous Bristlebird; and the newly-discovered subspecies caryochrous of the Rufous bristlebird, which occurs in open eucalyptus forest with dense understorey in the Otway Range.
The genus Dasyornis was sometimes placed in the Acanthizidae or, as a subfamily, Dasyornithinae, along with the Acanthizinae and Pardalotinae, within an expanded Pardalotidae, before being elevated to full family level by Christidis & Boles (2008).Higgins, P.J.; & Peter, J.M. (eds). (2003). Handbook of Australian, New Zealand and Antarctic Birds. Volume 6: Pardalotes to Shrike-thrushes. Oxford University Press: Melbourne. Christidis, Les; & Boles, Walter E. (2008). Systematics and taxonomy of Australian birds. CSIRO Publishing: Melbourne.
Once placed within various Northern Hemisphere lineages (such as Old World warblers or Old World flycatchers), the Dasyornithidae's closest relatives are now known to be Australian endemics such as the pardalotes and honeyeaters. Although their exact position within the Australasian basal lineages of passerines is not fully resolved, Marki et al.’s 2017 study, the first to sample and sequence molecular data for all three species of bristlebirds, placed them within the ecologically diverse infra-order Meliphagides (formerly known as Meliphagoidea). This lineage consists of five families: Maluridae (fairywrens and allies), Acanthizidae (thornbills and gerygones), Meliphagidae (honeyeaters), Pardalotidae (pardalotes) and Dasyornithidae (bristlebirds). While other families within this grouping are highly speciose (e.g.: the Meliphagidae (honeyeaters) family, with 187 species), Dasyornis broadbenti, D. brachypterus and D. longirostris are the only three known species of bristlebirds. Marki et al. found strong support for D. broadbenti as sister lineage to D. brachypterus and D. longirostris, having diverged from its relatives in the mid-Miocene (ca.13 Mya), with D. brachypterus and D. longirostris diverging in the early Pliocene (ca. 5 Mya). They infer from this that genetic divergences within the family may be greater than their similar morphologies might suggest, and urge denser sampling to explore the possibility of overlooked cryptic species.
After two centuries of European colonisation, two of the three species of bristlebirds are endangered (see Status and Conservation below), and all have restricted and disjunct ranges. Their distributions are non-overlapping, with the Western bristlebird the most specialised/localised/isolated—it inhabits only a tiny area of dense heathland on the south-west coast of Western Australia. On the east coast, the Eastern bristlebird occupies a wider range of habitats: relict pockets of far south-east Queensland and northern New South Wales, and coastal fringes south of Sydney to the Victorian border. The Rufous bristlebird's range is dense coastal shrubland and heathland in far south-west Victoria and extreme eastern South Australia. The least-shy member of the family, the newly discovered subspecies caryochrous, occurs in open eucalyptus forest with dense understorey in the Otway Range, but is also found in car parks, tracks and gardens along the edges of its dense habitat (hence, perhaps, its reputation for boldness).
They generally occur in pairs, but their social structure has not been studied closely. Most of the food is found by foraging on the ground. Birds forage in pairs, making small contact calls to keep in touch, and constantly flicking their tails whilst moving. The major part of the diet is composed of insects and seeds. Spiders and worms are also taken, and birds have been observed drinking nectar as well.
The breeding behaviour of bristlebirds is poorly known. They are thought to mostly be monogamous and defend a territory against others of the same species. The Western bristlebird breeds July–October, the two eastern species between August and February. All are single-brooded, and eastern and Rufous bristlebirds will lay replacement clutches if the first one is lost, an important factor in the success of captive breeding programs being undertaken in Queensland for the critically endangered northern subspecies monoides of the Eastern bristlebird.
The bird nest is constructed by the female in low vegetation and is a large ovoid dome with a side entrance with finer grasses for lining. Two eggs are laid, white or dullish whitish-brown or pink dotted with purplish-brown spots. As far as is known only the female avian incubation the clutch, for a period of between sixteen and twenty-one days. Both sexes feed the young. The nestling stage is known to be long, eighteen to twenty-one days.
|
|
