Tipping Point for Cockatoos in Perth

Tipping Point for Cockatoos in Perth

Hot Topics in Ecology

Tipping Point for Cockatoos in Perth

Synthesis by RJ Standish, RJ Hobbs and LE Valentine* − Environmental Decisions Group, The University of Western Australia. *Current address: Centre of Excellence for Climate Change, Woodland and Forest Health, Murdoch University
Carnaby’s black cockatoo feeding on Banksia attenuta. Photo LE Valentine

Flocks of these gregarious birds are common-place in Perth during the non- breeding season (JanuaryJuly). They are strongly evocative of the west Australian landscape and an important connection to nature for people living in the city. Yet these regular sightings hide an important truth: Carnabys black cockatoo has undergone a major decline in range and abundance since the 1960s.The bird is listed as endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act. Work by Dr Denis Saunders over the past 30 years and by others shows that the cockatoos have declined in response to landscape fragmentation and habitat loss in south-western Australia.

The Swan Coastal Plain (SCP) is an important foraging area for the cockatoos during their non-breeding season, where potentially a quarter of the breeding population feed in banksia woodlands and commercial pine plantations. However, a rapidly growing urban population coupled with declining rainfall is straining Perths land and water supplies.  Banksia woodland is being cleared to make way for housing and infrastructure while pines are being harvested to fulfill a commercial contract and because these trees limit groundwater recharge. Native vegetation on the SCP was 41.2 % of pre-European extent in 2006 (~549 567 ha) and ~15 389 ha was under pine in 2009.

Effective land-use planning could ensure that critical foraging habitat is retained or restored on the SCP. A mix of banksia-woodland species are suggested for the restoration of feeding habitat, along with the retention of priority banksia woodlands and some pine plantations. While restoration is undoubtedly part of the effort needed to ensure the survival of the cockatoos, it may not compensate for the ongoing loss of banksia woodland and pine. Ultimately, Carnabys black cockatoo may be left with insufficient food resources.

Hot Topic Lead Author: 
Name: Dr Rachel Standish
Email: rachel.standish@uwa.edu.au
Phone: 08 -6488-1073

Date approved: 
Saturday, March 8, 2014 - 04:10
ID Title Location Type
7018 Saunders, D. A. & Ingram, J. A. (1998) Twenty-eight years of monitoring a breeding population of Carnaby's Cockatoo. Pacific Conservation Biology 4: 261–270. Coomallo Creek, 400 km north of Perth, Western Australia Natural experiment
7017 Kabat AP, Scott R, Kabat TJ and Barrett G (2011) Unpublished report by Birdlife Australia for the Western Australian Department of Environment and Conservation. Swan Region, Swan Coastal Plain and adjacent jarrah forest, Perth, Western Australia Census of CBC undertaken on 7 April 2011, which identified Carnaby’s Cockatoo roost sites throughout the species’ range: 185 sites were surveyed spanning just north of Gingin to Esperance in the south.
6858 Valentine L. E. & Stock W. (2008) Food Resources of Carnaby’s Black-Cockatoo (Calyptorhynchus latirostris) in the Gnangara Sustainability Strategy study area. Unpublished report to the Forests Products Commission. Northern Swan Coastal Plain, Perth, Western Australia literature review plus large-scale natural experiment informed by GIS and field data to estimate food resource availability in banksia woodlands and pine plantations within the study area
6859 Finn H., Stock W., Valentine L. E. (2009) Pines and the ecology of Carnaby‘s Black- Cockatoos (Calyptorhynchus latirostris) in the Gnangara Sustainability Strategy Area. Unpublished report to the Forests Products Commission. Northern Swan Coastal Plain, Perth, Western Australia literature review plus field surveys
6860 Cale, B. (2003) Carnaby's Black-Cockatoo (Calptorhynchus latirostris) Recovery Plan 2002 - 2012 Western Australian Wildlife Management Program No. 36 Perth, Department of Conservation and Land Management Western Australian Threatened Species... south-western Australia review and guidelines
6862 Saunders, D. A., (1990) Problems of survival in an extensively cultivated landscape: the case of Carnaby’s cockatoo Calytorhynchus funereus latirostris. Biological Conservation 54: 111–124. wheatbelt, south-western Australia natural experiment