NSW Scientific Committee - final determination
The Scientific Committee found that:
1. The eastern form of the Black-chinned Honeyeater is found predominantly west of the Great Dividing Range in a narrow belt through NSW into southern Queensland, and south into Victoria and South Australia where it occupies eucalypt woodlands within an approximate annual rainfall range of 400-700mm (Blakers et al. 1984). In NSW, the species is mainly found in woodlands containing box-ironbark associations and River Red Gum. Black-chinned Honeyeaters are also known from drier coastal woodlands of the Cumberland Plain, Western Sydney and in the Hunter, Richmond and Clarence Valleys.
2. The Black-chinned Honeyeater is a medium-sized green and white passerine bird with a black head. The species builds compact, cup-shaped nests and feeds on arthropods, nectar and lerp from eucalypt foliage and bark (Blakers et al. 1984).
3. Black-chinned Honeyeaters were widely distributed and occurred naturally at low densities. Black-chinned Honeyeaters were recorded at densities ranging between 0.02 to 0.26 per hectare in box-ironbark forests in Victoria (Traill 1995) and in northern NSW at 0.28 per hectare (Oliver et al. 1999).
4. The Black-chinned Honeyeater has declined in numbers and is no longer found in parts of its range. For example, population declines have been reported from the Cumberland Plain, Western Sydney (Hoskin 1991; Keast 1995; Egan et al. 1997) and the species was absent throughout a survey of 195 remnants near Forbes (Major et al. 1998). Incidental reports also show a decline in the occurrence of birds with the species now only occasionally recorded at a site near Moree where once they were regular, and an apparent 10 year absence from a once regular recording site near Wagga Wagga. The species does not persist in remnants less than 200 ha in area. Reid (1999) identified the species as a 'decliner' in a review of bird species' status in the NSW sheep-wheatbelt.
5. Black-chinned Honeyeaters are threatened by clearance and the fragmentation of woodland habitat. Reductions in remnant habitat size leads to the isolation of honeyeater populations which increases their vulnerability to extinction from stochastic events, and decreases their genetic viability in the long term. As the species occurs at low densities and is only found in relatively large remnants, this further exacerbates the species vulnerability.
6. Black-chinned Honeyeaters are likely to experience high levels of competition from aggressive honeyeater species such as Noisy Miners or White-plumed Honeyeaters, both of which occur at high densities in small remnants of Red Gum and box-ironbark associations. In addition, increased nest predation is expected from increasing populations of predators such as Pied Currawongs and Australian Ravens, particularly in small remnants (Major et al. 1998).
7. In view of the above points, the Scientific Committee is of the opinion that the sub-species of the Black-chinned Honeyeater (eastern subspecies) Melithreptus gularis gularis, is likely to become endangered unless the circumstances and factors threatening its survival or evolutionary development cease to operate, and is therefore eligible for listing as a vulnerable species.
Proposed Gazettal date: 26/10/01
Exhibition period: 26/10/01 - 30/11/01
Blakers, M., Davies, S.J.J.F. and Reilly, P.N. (1984). 'The Atlas of Australian Birds'. Melbourne University Press: Melbourne.
Egan, K., Farrell, J. and Pepper-Edward, D. (1997). Historical and seasonal changes in the community of forest birds at Longneck Lagoon Nature Reserve, Scheyville, New South Wales. Corella 21, 1-16.
Hoskin, E. (1991). 'Birds of Sydney 1770-1989'. Surrey Beatty and Sons: Sydney.
Keast, A. (1995). Habitat loss and species loss: the birds of Sydney 50 years ago and now. Australian Zoologist 30, 3-25.
Major, R., Christie, F. and Gowing, G. (1998). 'The Value of Remnant Vegetation for Birds in the New South Wales Wheatbelt'. Australian Museum: Sydney.
Oliver, D., Ley, A., Ford, H. and Williams, B. (1999). Habitat of the Regent Honeyeater, Xanthomyza phrygia and the value of the Bundarra-Barraba region for the conservation of avifauna. Pacific Conservation Biology 5, 224-239.
Reid, J. (1999). 'Threatened and Declining Birds in the New South Wales Sheep-wheatbelt: Diagnosis, Characteristics and Management'. Report to NSW NPWS: Sydney.
Traill, B.J. (1995). Competition and co-existence in a community of forest vertebrates. Ph. D. Thesis, Monash University.