Swan Coastal Plain Project

© Bansi Shah

© Eleanor Adams

The first phase of the Swan Coastal Plain Project is now over. Stay tuned for more information! In the meantime, you can read the executive summary and download the project report below.

Download Carnaby's Cockatoo SCP Report (2006) (3.9 MB)

Executive Summary:

Once numerous in Western Australia, the highly mobile Carnaby's Black-Cockatoo (Calyptorhynchus latirostris) is now listed as endangered, with populations declining dramatically due to land clearing for agriculture in regional areas and for urban development around Perth.  The last 45 years has seen a 50% decrease in the species' range and abundance, with local extinctions in some regions. 

This project aimed to collect critically important baseline information to assist future conservation planning in the rapidly developing Swan region.  Area and roost counts were conducted on a number of days in order to determine relative abundance and minimum population size.  Roost counts were continued over a number of days and a longer-term study was conducted over four months to determine whether birds returned to the same roost sites. To determine movement patterns and potentially important areas for Carnaby's Cockatoos, a flock-following exercise was conducted over a number of days in Perth's northern region, which contains large areas of pine plantation and native vegetation. Feeding information was gathered over a nine month period to determine what native and non-native plant species were being used for food by the birds.

A minimum population estimate of 4510 was obtained via a roost count on 29 April 2006.  Carnaby's Cockatoos occurred over the entire Swan Coastal Plain and in all types of habitat.  The birds were most abundant in areas which contained a high proportion of pine plantations or remnant pines and areas with native bush, such as the northern region, Rockingham-Peel region and the South Metro region.  Birds were least abundant in highly urbanised and cleared areas, such as the North Metro region. Carnaby's Cockatoos used the same roost sites over a period of time, and identified roost sites were primarily tall pine trees and Eucalypt trees with apparently dense canopies. Flocks in the northern region used the pine plantations for roosting and feeding in the morning and afternoon, moving into the surrounding area in the middle of the day, particularly towards surface water from which to drink.  Flocks generally moved up to 13 km within a day, with a maximum distance of 6.84 km covered in one hour, the greatest distances generally being covered in the early morning or late evening.  Birds were observed feeding on both native and non-native plant species; primarily native Banksia spp. and introduced Pinus spp.  Significantly, pine plantations appeared to play an important role in the ecology of Carnaby's Cockatoos on the Swan Coastal Plain - a large proportion of birds counted were in pine plantations, roosted in pine trees, and fed on pine cones.

These studies show that Carnaby's Cockatoos use the entire landscape of the Swan Coastal Plain, with a significant preference for large tracts of native vegetation and pine plantations.  These results have important conservation implications for the Carnaby's Cockatoo population with respect to clearing, and possibly fragmentation, of the remaining native vegetation in and around the Perth metropolitan area.  Progressive removal over the next 10 - 20 years of pine plantations and remnant pine trees on the Swan Coastal Plain will have a significant negative impact on the population of Carnaby's Cockatoos using the Swan Coastal Plain.  Measures will need to be taken by the government to ameliorate impacts on this endangered endemic species.