Red-tailed black-cockatoo (coastal subspecies) (Calyptorhynchus banksii banksii) - critically endangered species
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Red-tailed Black-Cockatoo (coastal subspecies) Calyptorhynchus banksii banksii (Latham, 1790) as a CRITICALLY ENDANGERED SPECIES in Part 1 of Schedule 1A of the Act, and as a consequence, to omit reference to Calyptorhynchus banksii (Latham, 1790) from Part 1 of Schedule 2 (Vulnerable species) of the Act. Listing of Critically Endangered species is provided for by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. The Red-tailed Black-Cockatoo is a large (60 cm) black cockatoo with a bushy crest and a red tail panel; the female has a white bill, fine yellow spots and bars on the head and body, and an orange tail panel with fine black bars. It is very similar to the smaller Glossy Black-Cockatoo, which has a small crest, softer and less discordant calls, and females have a grey bill and large yellow blotches on the head. The Yellow-tailed Black-Cockatoo has a yellow ear patch and tail panel, and loud wailing calls.
2. The Red-tailed Black-Cockatoo is distributed throughout much of Australia, but its southern and inland populations are fragmented into isolates that constitute separate subspecies (Higgins 1999). The Red-tailed Black-Cockatoo (coastal subspecies) Calyptorhynchus banksii banksii has been confirmed as historically occurring in NSW south to Sydney (McAllan 2002), but it rapidly contracted to the far North Coast (Bellinger and Macleay River valleys), and was last seen regularly on the Tweed River in the 1970s (Higgins 1999). Since that time there have been very occasional sightings in extreme north-east NSW, around the Tweed and lower Richmond Valleys (NSW Wildlife Atlas). Of the four valid or probably valid records of the coastal Red-tailed Black-Cockatoo since 1980, only one sighting, at Bungawalbin Nature Reserve, was supported by an expert identification eliminating the Glossy Black-Cockatoo, and one other, at Round Mountain (Bogangar), was an expert identification by a CSIRO biologist during the State Forests Murwillumbah District environmental assessment. The other two are probably correct, because one (at Wilsons Creek north of Alstonville) was made by a knowledgeable observer, and the other at Cabarita on the Tweed coast described feeding on a known food source (Horsetail She-oak) of the Red-tailed Black-Cockatoo which has not been recorded for the Glossy Black-Cockatoo. There were no records in the first national bird atlas, and a record(s) in only one extreme north-eastern one-degree grid, at the lowest reporting rate, in the second national atlas (Blakers et al. 1984; Barrett et al. 2003). Recent reports of ‘Red-tailed’ Black-Cockatoos on the slopes and tablelands of NSW, and almost all reports from the coast, are almost certainly referable to the Glossy Black-Cockatoo. There are no records of the coastal Red-tailed Black-Cockatoo since 1980 in the NSW annual bird reports (published by the NSW Field Ornithologists Club), even though this is a noisy and conspicuous species. Expert ornithological surveys in the Richmond Valley (Gosper 1986, 1992; Gosper & Holmes 2002) and Byron Shire (Milledge 1991) obtained no records of the species. Gilmore and Parnaby (1994) quote recent ( i.e. pre-1994) sightings restricted to the northern parts of the Richmond Range in the upper Clarence and Richmond Valleys, but without supporting details or date, and an unverified historical record in the 1960s from the Koreelah Range (Norris 1964). Some doubtful records of Red-tailed Black-Cockatoos from the tablelands and North Coast are probably based on misidentifications of Glossy Black-Cockatoos. These misidentifications of the Red-tailed Black-Cockatoo give a misleading impression of its geographical distribution as well as an inflated impression of its abundance.
3. The subspecies’ population and geographic distribution have declined greatly in NSW, from historical occurrence south to Sydney, to a remnant population on the Tweed River that has not been seen regularly in the past 30 years. Over the 60 years (three generations) up to 2000, the subspecies declined progressively at its last regular site on the Tweed River from flocks of more than 60 birds in the early 1940s, then 25-30 observed into the 1950s, followed by a decline to 3-5 birds in the 1960s and two birds by 1975. It has been seen only occasionally since (Higgins 1999). The number of individuals of subspecies Calyptorhynchus banksii banksii in NSW is uncertain, but is now extremely low. The last reliable reports were of small groups of birds (fewer than 10). Remaining NSW birds may represent incursions by, or possibly interchange with, the Queensland population, which is abundant in the tropics.
4. Historically, the main threat has been clearing of forest for agriculture and settlements, and degradation of forests by logging. The cockatoo’s most productive habitats, fertile riparian flats and floodplains, were heavily targeted and are now severely fragmented. Another subspecies, C. b. graptogyne (listed nationally, and in Victoria and South Australia, as Endangered) is adversely affected even by the loss of dead nesting trees in paddocks (Maron 2005), a situation that is inferred to apply on much of the coastal plain north of Sydney. ‘Clearing of native vegetation’ and ‘Loss of hollow-bearing trees’ are listed as Key Threatening Processes under the NSW Threatened Species Conservation Act 1995.
5. Subspecies Calyptorhynchus banksii banksii is not listed as threatened under other state or national legislation. A separate population occupying primarily the Darling Riverine Plains Bioregion of inland NSW is the subspecies C. b. samueli, which is unlikely to have interchange with the coastal population.
6. The Red-tailed Black-Cockatoo (coastal subspecies) Calyptorhynchus banksii banksii (Latham, 1790) is eligible to be listed as a Critically Endangered species as, in the opinion of the Scientific Committee, it is facing an extremely high risk of extinction in New South Wales in the immediate future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:
Clause 14
The species has undergone, is observed, estimated, inferred or reasonably suspected to have undergone or is likely to undergo within a time frame appropriate to the life cycle and habitat characteristics of the taxon:
(a) a very large reduction in population size,
based on:
(d) An index of abundance appropriate to the taxon
(e) geographic distribution, habitat quality or diversity, or genetic diversity.
Clause 16
The estimated total number of mature individuals of the species is:
(a) very low,
and:
(d) a projected or continuing decline is observed, estimated or inferred in:
(i) an index of abundance appropriate to the taxon
(ii) geographic distribution, habitat quality or diversity, or genetic diversity; and
(e) the following conditions apply:
(i) the population or habitat is observed or inferred to be severely fragmented;
(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or locations
Clause 17
The total number of mature individuals of the species is observed, estimated or inferred to be:
(a) extremely low.
Dr Richard Major
Chairperson
Scientific Committee
Proposed Gazettal date: 31/07/09
Exhibition period: 31/07/09 - 25/09/09
References:
Barrett G, Silcocks A, Barry S, Cunningham R, Poulter R (2003) ‘The new atlas of Australian birds.’ (RAOU: Melbourne)
Blakers M, Davies SJJF, Reilly PN (1984) ‘The atlas of Australian birds.’ (Melbourne University Press: Melbourne)
Gilmore AM, Parnaby HE (1994) ‘Vertebrate fauna of conservation concern in north-east NSW forests.’ North East Forests Biodiversity Study Report No. 3e, NSW NPWS.
Gosper DG (1986) Birds in the Richmond River district, NSW, 1973-1983. I. Distribution. Corella 10, 1-16.
Gosper DG (1992) Forest bird communities in the Richmond River district, New South Wales. Corella 16, 78-88.
Gosper DG, Holmes G (2002) Status of birds in the Richmond River district, New South Wales, 1973-2000. Corella 26, 89-105.
Higgins PJ (Ed.) (1999) ‘Handbook of Australian, New Zealand and Antarctic birds (Vol. 4).’ (Oxford University Press: Melbourne)
Maron M (2005) Agricultural change and paddock tree loss: implications for an endangered subspecies of Red-tailed Black-Cockatoo. Ecological Management and Restoration 6, 207-212.
McAllan IAW (2002) Early records of the Red-backed Fairy-wren and Red-tailed Black-Cockatoo from New South Wales. Australian Bird Watcher 19, 230-234.
Milledge DG (1991) A survey of the terrestrial vertebrates of coastal Byron Shire. Australian Zoologist 27, 66-90.
Norris AY (1964) Observations on some birds of the Tooloom Scrub, northern New South Wales. Emu 63, 404-412.
NSW Field Ornithologists Club (1990-2007) NSW annual bird reports and rare bird reports, published annually in Australian Birds.