National Recovery Plan for Eastern Bristlebird Dasyornis brachypterus
The Eastern Bristlebird (Dasyornis brachypterus) is listed as ‘Endangered’ in Australia under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and under state legislation in Queensland, New South Wales (NSW) and Victoria. The species is also listed as ‘Endangered’ by the International Union for Conservation of Nature (IUCN). The northern population of the Eastern Bristlebird meets the criteria for ‘Critically Endangered’ by the IUCN.
The Eastern Bristlebird is a small, brown, well-camouflaged, ground-dwelling bird. It is generally shy and cryptic, spending most of its time in low, dense vegetation and rarely appearing in the open or flying. The species has contracted to four genetically isolated populations in three disjunct areas of south-eastern Australia: south-eastern Queensland/north-eastern NSW (northern population), the Illawarra and Jervis Bay regions of eastern NSW (central populations) and the NSW/Victorian border coastal region (southern population). Each of the geographically separate regional populations is comprised of one or more disjunct local populations or colonies.
Limited evidence suggests that Eastern Bristlebirds in the northern population are morphologically distinct from the more southerly populations. Northern birds have previously been considered a distinct sub-species, Dasyornis brachypterus monoides, while central and southern populations comprise the nominate sub-species Dasyornis brachypterus brachypterus. However, recent genetic analysis does not support sub-speciation.
The total national population of the Eastern Bristlebird is estimated at approximately 2500 birds, with two populations of around 1000 individuals. Population estimates should be recalculated with updated vegetation mapping and results of standard census techniques.
The Eastern Bristlebird inhabits a broad range of vegetation communities with a variety of plant species compositions that are generally defined by a similar structure of low, dense, ground or understorey vegetation. The species occupies fire-prone habitats and its response to fire is highly variable, however, the Eastern Bristlebird is particularly vulnerable to large-scale, intense fires. The extent, intensity and frequency of fires are all important in determining habitat suitability, along with the presence of unburnt refuges.
The main threat to the Eastern Bristlebird is the loss or fragmentation of suitable habitat, which can be caused by inappropriate fire regimes and clearing for urban or agricultural development. Habitat loss is recognised as the main process that has reduced the distribution and abundance of the Eastern Bristlebird in the last 150 years. Predation is a potential threat to the species, particularly by feral predators and particularly after fire. Other threats include habitat degradation from feral animals and livestock and invasion of weeds, genetic bottlenecks and inbreeding, climate change and human disturbance.
The long-term objective of this Eastern Bristlebird recovery program is the stabilisation of all populations. This will involve enhancing the northern population to a viable size, maintaining the stability of the central populations, and establishing an additional southern population in Victoria, bringing the size of the southern population to a viable level. Viable population size will be determined by population viability analysis (PVA). Attaining this long-term objective will involve the protection and management of habitat, the management of threats and enhancement of wild populations through captive breeding, augmentation and reintroduction. The objectives, criteria and actions proposed in this recovery plan work towards that objective and build on those in previous plans.
Actions required for the recovery of the Eastern Bristlebird include: survey, monitoring and mapping of all populations and habitat; maintenance or improvement in the condition and extent of habitat; management of threats, including fire, feral predators, exotic herbivores, weeds, genetic bottlenecks and climate change; enhancement of the northern and southern populations to viable levels; research to improve knowledge of the species; effective coordination of the recovery effort; improved communication between stakeholders and community involvement. The estimated total cost of implementing recovery actions is $3,609,000 over the five years of this plan.