EN
Long-billed Black-cockatoo Zanda baudinii



Justification

Justification of Red List Category
Despite this species having a moderately small population, only about 10% of individuals make up the breeding population, and numbers are in decline. The rate of decline is inferred from changes in habitat and competition to be >50% in three generations, and hence the species is therefore listed as Endangered.

Population justification
The 1995-2004 surveys of the species suggest the total population is probably still 10,000-15,000 individuals but that only c.10% of those birds make up the breeding population (P. Mawson in litt. 2004).

Trend justification
It is suspected to be in continuing decline, at an unquantified rate, owing to illegal shooting, competition for nest sites with feral bees, and loss of nesting and feeding habitat, owing to logging (P. Mawson in litt. 2004). The population density is believed to be declining at an unquantified rate (Johnstone et al. 2007). The reporting rate probably declined between the 1977–1981 and 1998–2001 (Olsen et al. 2003) but taxonomic changes in the first Birds Australia Atlas and confusion with other Black-Cockatoos since make comparisons difficult. Given the lack of any recent quantitative data, the rate of decline is inferred from changes in habitat and competition to be >50% in 3 generations (Garnett et al. 2011).

Distribution and population

Zanda baudinii occurs in the south-west of Western Australia, Australia, mostly between Perth, Albany and Margaret River. Breeding occurs in the far south of the range, from Nornalup north to near Bridgetown, though sometimes further north to Lowden and Harvey (Higgins 1999). The species has disappeared from c.25% of its range, and is thought to have declined in density over at least another 25%. Surveys during 1995-2004 suggest that the population is probably 10,000-15,000 individuals but that only c.10% of those birds make up the breeding population in any year (P. Mawson in litt. 2004). Many birds thought to be this species in the far south of its range are in fact Carnaby's Black-cockatoo Z. latirostris, which occurs in the forest areas at a ratio of 5:1 with respect to Z. baudinii (P. Mawson in litt. 2004). 

Ecology

Restricted to moist, heavily forested areas dominated by marri Eucalyptus calophylla, karri E. diversicolor and jarrah E. marginata. Its overall non-breeding range may be determined by distribution of marri, though it does occur in apple and pear orchards and occasionally in wandoo E. wandoo woodland (Higgins 1999). The species mainly feeds on the seeds and flowers of marri, as well as the seeds of Banksia, Hakea and Dryandra species, Erodium botrys and jarrah, and additionally takes insect larvae (DEC, Western Australia 2007a). It also feeds on apple and pear seeds (DEC, Western Australia 2007a) and is considered a pest owing to the damage it causes when extracting seeds from crops in commercial orchards (Chapman 2007, DEC, Western Australia 2007a). Damage to commercial fruit crops is thought to be higher during local or seasonal shortages of marri seeds, and could be related to destruction of this habitat (DEC, Western Australia 2007a). The species may live for 25 to 50 years in the wild (DEC, Western Australia 2007a). It breeds in large hollows of old karri, marri and jarrah (Higgins 1999, DEC, Western Australia 2007a) within heavily forested areas (Higgins 1999), although recent work suggests that there are very few nest sites, that breeding occurs very infrequently and that many nest hollows are being taken over by feral bees (P. Mawson in litt. 2004). Breeding data has indicated that pairs raise, on average, 0.6 chicks each year. In years of poor marri seed production, the population may fail to raise any young at all (DEC, Western Australia 2007a). The species has a strong association with very large (greater than 1.5m diameter) and old (230-300 years) marri trees, which may exacerbate declines (P. Mawson in litt. 2004).

Threats

Up to a quarter of the species's habitat has been cleared for agriculture, with 8,933,294 m3 of marri harvested during 1976-1998 (P. Mawson in litt. 2004). Nest hollow shortage is considered the principal threat, as suitable hollows are considered scarce, only forming in trees at least 130 to 220 years of age, many of which have been preferentially felled (Chapman 2007). The past and present impacts of logging for marri, initially for woodchips and now for furniture grade sawlogs, are reducing the availability of food and nesting trees. The impact of logging and woodchipping has not been quantified. Although logging of old growth forest in the south-west has now stopped, habitat loss is still likely to be causing population declines. Feral European honey bees Apis mellifera have been found to occupy many potential nest sites, and are known to have caused the loss of chicks and killed a brooding female (P. Mawson in litt. 2004). Although the species has been fully protected since 1996, illegal shooting by orchardists still occurs (P. Mawson in litt. 2004, Chapman 2007) and poaching of eggs, chicks or birds for trade is an additional threat (Lee 2014). It is not known whether losses from shooting exceed productivity (P. Mawson in litt. 2004). Continued loss of forest to mining in some areas is also an issue, since revegetation will have no impact on conservation outcomes within the lifespan of this species (P. Mawson in litt. 2004). Ground water extraction removes important drinking areas and can impact vegetation (Lee 2012). Competition for nests from Wood Ducks Chenonetta jubatta is thought to be increasing as duck numbers increase in the south-west (P. Mawson in litt. 2004). Climate change resulting in reduced rainfall and increased temperature may cause distribution shifts and considerable changes in foraging and spatial ecology (Lee 2014).

Conservation actions

Conservation Actions Underway
CITES Appendix II. Protected under Australian law since 1996. Forest management has now changed so that woodchipping apparently ceased in 2003. Research into the breeding biology of the species is ongoing but is hampered by difficulties in finding nests (P. Mawson in litt. 2004). An information sheet was produced by the Government of Western Australia in 2007, outlining the status of the species and promoting non-lethal control methods by orchardists, e.g. exclusion netting (DEC, Western Australia 2007a). BirdLife Australia's Threatened Black Cockatoo Program is conducting research, monitoring and recovery actions to better help conserve this and other black cockatoo species. Actions include identifying and increasing priority habitat, better understanding population numbers and distribution, threats and how to alleviate them, increasing habitat connectivity, awareness and forming partnerships across stakeholders to better integrate the species needs into planning (Lee 2014).

Conservation Actions Proposed
Prevent illegal shooting in and around commercial orchard areas and more vigorously enforce anti-shooting legislation. Assist orchardists in developing a non-lethal damage mitigation strategy. Continue to raise awareness of the species's status amongst orchardists and promote non-lethal control methods (Chapman 2007). Develop and implement a feral bee control strategy. Retain mature and over-mature marri trees as nest and food sources as part of forest management prescriptions (P. Mawson in litt. 2004). Develop a repeatable population monitoring technique. Initiate monitoring in different parts of range.

Acknowledgements

Text account compilers
Benstead, P., Garnett, S., Harding, M., McClellan, R., Taylor, J., Allinson, T, Symes, A. & North, A.

Contributors
Chapman, T., Garnett, S. & Mawson, P.


Recommended citation
BirdLife International (2020) Species factsheet: Zanda baudinii. Downloaded from http://www.birdlife.org on 13/07/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 13/07/2020.