Black-eared miner (Manorina melanotis) - critically endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Black-eared Miner Manorina melanotis (Wilson, 1911) as a CRITICALLY ENDANGERED SPECIES in Part 1 of Schedule 1A of the Act and as a consequence, to omit reference to the Black-eared Miner Manorina melanotis (Wilson, 1911) from Part 1 of Schedule 1 (Endangered 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 Black-eared Miner Manorina melanotis (Wilson, 1911) is a medium-sized (25 cm), mostly grey honeyeater. It has an orange bill and legs, black mask, yellow eye skin, slight yellow tinge on the forehead and below the ears, an olive-yellow tinge in the wings and tail, and a white belly. It is very difficult to distinguish from the Yellow-throated Miner Manorina flavigula, which is paler with slightly more yellow tinge on the forehead and throat, and a white rump. Hybrids between these two species occur commonly, and have intermediate plumage characters.
2. The Black-eared Miner occurs in a restricted area of inland south-eastern Australia, inhabiting mature and old-growth mallee that has not been burnt for more than 50 years. About 95% of the species’ core distribution and abundance is in South Australia where it exists as a single population in one large reserve (Clarke et al. 2005), with the largest of four subpopulations being c. 240 birds (Garnett & Crowley 2000). In NSW the Black-eared Miner occurs only on Scotia Station (a reserve currently owned and managed by the Australian Wildlife Conservancy) and the adjacent Tarawi Nature Reserve, isolated from other Black-eared Miners in South Australia and Victoria (Clarke et al. 2005).
3. The number of mature individuals in NSW is extremely low with few records since 1980. Six Black-eared Miners in two colonial groups were recorded in 1985, and sightings of single Black-eared Miners were made in 1981 and 1985 (Higgins et al. 2001). Intensive surveys in 1993 found three colonies of hybrids on Scotia Station, and no Black-eared Miners or hybrids in nearby areas (Higgins et al. 2001). Annual bird reports between 2000 and 2004 recorded small numbers of Black-eared Miners (two birds on each occasion) in Tarawi Nature Reserve and Scotia Station in 2001 and 2002 only (NSW Field Ornithologists Club data 1988-2007). The most recent survey, in spring 2007 in Scotia and Tarawi, found a total of six birds classified as Black-eared Miners (M. Clarke pers. comm. 22/07/08). On the basis of this distribution, reporting rate, and number of colonies (Higgins et al. 2001; Barrett et al. 2003; Clarke et al. 2005), the number of Black-eared Miners in NSW is estimated to be between 10 and 20 birds. Given recent drought conditions, the current NSW population of the Black-eared Miner is suspected to be lower than in 2000-02 (R. Clarke pers. comm. 03/07/08).
4. A comparison of historical and current records shows that the species’ NSW distribution has contracted westward from an area extending from the Darling Anabranch and the Murray River east of Mildura (south of Mallee Cliffs National Park), to the South Australian border area around Scotia Station and Tarawi Nature Reserve (Clarke et al. 2005). The species was recorded in two 1-degree grids in western NSW in the first national bird atlas in 1997-81, at high reporting rates (more than 40% of surveys per grid), with one breeding record (Blakers et al. 1984). It was reported in the same two grids in the second national bird atlas in 1998-2002, at low reporting rates (less than 10% of surveys per grid), with no breeding records in NSW (Barrett et al. 2003), suggesting a decline occurred over the two decades. As recent surveys in NSW found pure Black-eared Miners at only one location (Clarke et al. 2005), the species’ extent of occurrence and area of occupancy in NSW are almost certainly less than 100 km2 and 10 km2, respectively. The species is known, with high confidence, to be decreasing globally (Garnett & Crowley 2000).
5. The main causes of decline of Black-eared Miners in NSW are habitat fragmentation and hybridisation. The Yellow-throated Miner readily colonises fragmented mallee, and stock watering points within contiguous mallee can attract and sustain dispersing individuals in habitat more typically occupied by Black-eared Miners (M. Clarke pers. comm. July 2008). Once brought into contact by habitat modification the two species readily interbreed (Garnett & Crowley 2000; Clarke et al. 2001; Higgins et al. 2001). In addition, mallee habitat can be degraded by stock and small-scale clearing occurs around watering points (M. Clarke pers. comm. July 2008; R. Clarke pers. comm. July 2008). Black-eared Miners occupy fire-prone habitat where uncontrollable wildfires can eliminate entire miner populations (Clarke et al. 2005). Predation by cats and foxes may also be a threat. ‘Clearing of native vegetation’, ‘High frequency fire resulting in the disruption of life cycle processes in plants and animals and loss of vegetation structure and composition’, ‘Predation by the Feral Cat Felis catus (Linnaeus, 1758)’ and ‘Predation by the European Red Fox Vulpes vulpes (Linnaeus, 1758)’ are listed as Key Threatening Processes under the Threatened Species Conservation Act 1995.
6. Based on the extensive historical clearing of mallee that occurred in western NSW, the species’ NSW population is inferred to have been severely fragmented. Colonies of Black-eared Miners are partially isolated from others by the presence of Yellow-throated Miners and hybrids on intervening land.
7. The Black-eared Miner is listed as Threatened under the Victorian Flora & Fauna Guarantee Act 1988 and Endangered on the Victorian Advisory List. It is listed as Endangered in South Australia, and under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
8. Black-eared Miner Manorina melanotis (Wilson, 1911) 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 15
The geographic distribution of the species is estimated or inferred to be:
(a) very highly restricted,
and
(d) a projected or continuing decline is observed, estimated orinferred in:
(i) an index of abundance appropriate to the taxon
(ii) geographic distribution, habitat quality or diversity, or genetic diversity:
(e) the following conditions apply:
(i) the population or habitat is observer 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 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;
(e) the following conditions apply:
(i) the population or habitat is observed or inferred ot 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: 11/12/09
Exhibition period: 11/12/09 – 29/01/10
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)
Clarke RH, Boulton RL, Clarke MF (2005) Estimating population size of the Black-eared Miner, with an assessment of landscape-scale habitat requirements. Pacific Conservation Biology 11, 174-188.
Clarke RH, Gordon IR, Clarke MF, (2001) Intraspecific phenotypic variability in the Black-eared Miner (Manorina melanotis): human-facilitated introgression and the consequences for an endangered taxon. Biological Conservation 99, 145-155.
Garnett S, Crowley G (Eds) (2000) ‘The action plan for Australian birds 2000.’ (Environment Australia: Canberra)
Higgins PJ, Peter JM, Steel WK (Eds) (2001) ‘Handbook of Australian, New Zealand and Antarctic Birds (vol. 5).’ (Oxford University Press: Melbourne)
NSW Field Ornithologists Club (1988-2007) NSW annual bird reports and unusual sighting reports, published in Australian Birds and Birding NSW Newsletter.