NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. The Eastern Bristlebird is a passerine bird approximately 200 millimetres in length, weighing 40 grams. It is terrestrial, camouflaged, shy and cryptic. It is capable of only very short flights. The species is generally detected singly or in pairs at densities up to 25 birds per 100 hectares. It is currently categorised as Vulnerable on Schedule 2 of the Threatened Species Conservation Act.
2. The Eastern Bristlebird lays a clutch of two eggs and raises only one fledgling per nest. Nests are deserted after only slight disturbance.
3. The Eastern Bristlebird is rarely seen but may be detected by its distinctive, loud calls.
4. Eastern Bristlebirds are currently confined to three disjoint areas of south-eastern Australia:
- the NSW/Queensland border region
- the Illawarra region
- the NSW/Victorian border region
The total population is estimated at less than 2000 individual birds.
5. The evidence from recent surveys is that the total population has declined. The northern populations declined by approximately 50% between 1989 and 1992. Only two populations, both within the Illawarra region, are likely to exceed 500 birds. These populations occur on the Budderoo Plateau and the Bherwerre Peninsula.
6. The habitat of the Eastern Bristlebird is characterised by low dense vegetation. Fire is a feature of all areas where known populations occur. Given the poor flight ability of the species it is though that few individuals survive the passage of fire, survival is dependant on the availability of fire refuges and recolonisation may be relatively slow.
7. The nature of the fire regime is therefore crucial to the survival of the species and changes to the fire regime have been implicated as a cause of population decline.
8. Given the evidence of the decline in the numbers of the species, the fragmented distribution of the populations, the impacts of disturbance on nesting success and the effects of fire the Scientific Committee is of the opinion that the Eastern Bristlebird is likely to become extinct in nature in New South Wales unless the factors threatening its survival cease to operate.
9. Accordingly the Scientific Committee proposes that the Eastern Bristlebird be included on Part 1, Schedule 1 of the Threatened Species Conservation Act.
Associate Professor Paul Adam