Brown treecreeper (eastern subspecies) (Climacterus picumnus victoriae) - vulnerable species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Brown Treecreeper (eastern subspecies) Climacteris picumnus victoriae (Mathews, 1912), as a VULNERABLE SPECIES on Schedule 2 of the Act. Listing of Vulnerable Species is provided for by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee found that:
1. The eastern subspecies of the Brown Treecreeper Climacteris picumnus victoriae is distributed through central NSW on the western side of the Great Dividing Range and sparsely scattered to the east of the Divide in drier areas such as the Cumberland Plain of Western Sydney, and in parts of the Hunter, Clarence, Richmond and Snowy River valleys.
2. The western boundary of the range of Climacteris picumnus victoriae runs approximately through Wagga Wagga, Temora, Forbes, Dubbo and Inverell and along this line the subspecies intergrades with the arid zone subspecies of Brown Treecreeper Climacteris picumnus picumnus (Schodde and Mason 1999).
3. The Brown Treecreeper is a medium-sized insectivorous bird that occupies eucalypt woodlands, particularly open woodland lacking a dense understorey. It is sedentary and nests in tree hollows within permanent territories, breeding in pairs or communally in small groups (Noske 1991). Birds forage on tree trunks and on the ground amongst leaf litter and on fallen logs for ants, beetles and larvae (Noske 1979).
4. The broad range of the Brown Treecreeper has not changed but it is now extinct in parts of its range. Declines in populations have been recorded from the Cumberland Plain (Hoskin 1991; Keast 1995; Egan et al. 1997), the New England Tablelands (Barrett et al. 1994), the Inverell district (Baldwin 1975), from Munghorn Gap Nature Reserve near Mudgee, and from travelling stock routes in the Parkes district (N. Schrader, unpublished). Reid (1999) identified the Brown Treecreeper as a 'decliner' in a review of bird species' status in the NSW sheep-wheatbelt.
5. Brown treecreepers are threatened by clearance and the fragmentation of the woodland habitat including removal of dead timber. Increased isolation decreases treecreeper vagility and increases the vulnerability of populations to extinction as a result of stochastic events. This species appears unable to maintain viable populations in remnants less then 200ha and its abundance decreases as remnant size decreases (Barrett et al. 1994). Fragmentation also leads to a skewed sex ratio in Brown Treecreeper populations because female birds are unable to disperse to isolated remnants, increasing the chance of local extinctions (Walters et al. 1999).
6. Habitat degradation, including loss of hollow bearing trees, threatens Brown Treecreeper populations. Grazing by stock in woodland areas leads to a decrease the diversity of ground-dwelling invertebrates (Bromham et al. 1999) decreasing the availability of food for the birds. In addition, Brown Treecreepers are likely to be threatened by such factors as increased competition with aggressive honeyeater species and increased levels of nest predation that are a consequence of fragmentation of habitat (Major et al. 1998).
7. In view of the above points, the Scientific Committee is of the opinion that the sub-species of the Brown Treecreeper (eastern subspecies) Climacteris picumnus victoriae, 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.
Gazettal date: 26/10/01
Exhibition period: 26/10/01 - 31/11/01
Baldwin, M. (1975). Birds of the Inverell District, NSW. Emu 75, 113-120.
Barrett, G.W., Ford, H.A. and Recher, H.F. (1994). Conservation of woodland birds in a fragmented rural landscape. Pacific Conservation Biology 1, 245-256.
Bromham, L., Cardillo, M., Bennett, A. and Elgar, M. (1999). Effects of stock grazing on the ground invertebrate fauna of woodland remnants. Australian Journal of Ecology 24, 199-207.
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.
Noske, R.A. (1979). Co-existence of three species of treecreepers in north-eastern New South Wales. Emu 79, 120-128.
Noske, R.A. (1991). A demographic comparison of cooperatively breeding and non-cooperative treecreepers (Climacteridae). Emu 91, 73-86.
Reid, J. (1999). 'Threatened and Declining Birds in the New South Wales Sheep-wheatbelt: Diagnosis, Characteristics and Management'. Report to NSW NPWS, Sydney.
Schodde, R. and Mason, I.J. (1999). 'The Directory of Australian Birds: Passerines'. CSIRO: Melbourne.
Walters, J., Ford, H. and Cooper, C. (1999). The ecological basis of sensitivity of Brown Treecreepers to habitat fragmentation: a preliminary assessment. Biological Conservation 90, 13-20.