Archived 2011-2012 topics: Proposed revisions to Australian endemics based on reassessments in The Action Plan for Australian Birds 2010

The following Australian endemic species have been proposed for global reassessment following publication of a comprehensive reassessment of the status of Australian birds (Garnett, S.T., Szabo, J. 2011 and Dutson, G. Action Plan for Australian Birds 2010. CSIRO, Melbourne)

Reassessment of the status of Australian species was undertaken through a review of all peer-reviewed and unpublished literature for the last ten years and through consultation with experts on each taxon either individually or in workshops held in every major Australian city during 2010.

Because of the extensive consultation process already undertaken to enable these reassessments for the Action Plan, we do not envisage that a great deal of further input through the forum process will be necessary for many of these species. Nevertheless, we would welcome any further comments on the proposed reassessments of the species below by 31 January 2012.

Partridge Pigeon Geophaps smithii: uplist to Vulnerable

Recent surveys in Kakadu and Litchfield National Parks, strongholds for the eastern subspecies previously listed as Near Threatened, demonstrate a decline >30% in 3 generations (16.8 years) compared to surveys in early 1990s. Research on the species suggests it needs patchy fires to provide a mix of cover and open feeding areas. In these parks, on Tiwi Islands and in north-western Western Australia, satellite mapping demonstrates that fires are frequent and widespread, especially in the late dry season when they are hottest. The data from the surveys can therefore be extrapolated to other areas. Our knowledge of when the decline in population became steep enough to warrant listing as Vulnerable is poor but is likely to have been accelerating gradually as populations become more scarce and less able to replace those that are lost – estimated to be the 08-12 assessment period. The surveys indicate a rapid historical loss (VU A2b), most likely because of reduced habitat suitability and introduced predators (VU A2ce); a loss that is likely to continue into the future. The previous criteria associated with NT (C2a(i)) is inappropriate because even if <10,000 individuals and declining, several populations are well in excess of 1000 individuals with none approaching 90% of the total population. It is thus proposed that the species is uplisted to Vulnerable under criterion A2bc, A3c, A4c, with ongoing declines of 30-40% over three generations (17 years) suspected based on monitoring data from several sites and inferred from deterioration in habitat quality. The change in status would be genuine and occurring within the last 10 years.

Christmas Island Imperial-pigeon Ducula whartoni: downlist to Near Threatened

Christmas Island Imperial-pigeon is currently classified as Vulnerable under criterion D2, being restricted to one small location and thought to be susceptible to the effects of introduced taxa.  Like other Christmas Island species, invasive Yellow Crazy Ants are a potential threat, however there are fewer ants in the canopy where the pigeons feed. Black Rats are present and may reduce nesting success but do not appear to have seriously affected the pigeon. Further introductions of invasive species or diseases remain possible threats, but there is not thought to be any plausible threat likely to rapidly drive the species to CR or EX. Vulnerable (D2) seems no longer to be applicable under more rigorously applied IUCN Red List guidelines and it is proposed that the species is downlisted to Near Threatened (D2), occurring at a single small location and potentially susceptible to the effects of invasive predators, competitors or disease, but with no plausible threat likely to lead to a very rapid future decline.

Red Goshawk Erythrotriorchis radiatus: downlist to Near Threatened

The Red Goshawk is currently listed as Vulnerable VU D1 on the basis of it having a population below 1,000 mature individuals. Recent estimates suggest the population is about 1,400 mature individuals. There are probably 100 pairs on Tiwi Islands and 600 pairs elsewhere across northern Australia from the Kimberley through the Northern Territory and through Queensland to northern New South Wales. While fewer than 10,000 individuals there is no evidence of declines. Even if declining C1 requires evidence and cannot be supposed, or inferred – there is no effective monitoring of the species, C2a(ii) does not apply because Tiwi Is separate from mainland. C2a(i) would only applies if 1200 birds on mainland are divided by the Carpentarian gap. As breeding occurs on the Roper R. and on the Lynd R. and there is a confirmed sighting in central Australia this gap seems unlikely. The change in status suggested is from new information on populations and greater observer awareness of the species. It is therefore proposed to downlist the species to NT under D1.

Grey Falcon Falco hypoleucos: uplist to Vulnerable

Currently listed as Near Threatened on the basis that the population may approach 1,000 individuals, the Grey Falcon may actually be below that threshold. The original listing was based on calculations in Garnett and Brouwer (1990) as follows: “By comparing the range and number of sightings per 1 degree block (Blakers et al. 1984), it can be calculated that the Grey Falcon occupies about two-thirds of the area occupied by the Peregrine Falcon F. peregrinus in Australia, but at an average of one quarter its density. There may therefore be only 1000 pairs of Grey Falcons, giving a total population of fewer than 5000 individuals…. The species may have been eliminated from former breeding areas, particularly those with more than 250 mm annual rainfall, following clearance and agricultural development.” Grey Falcon enthusiast Jonny Schoenjahn, who has followed up every record that he can over the last decade, has recalculated based on comparison with Peregrine Falcon densities: “The Grey Falcon occupies two third of the area of the Peregrine (365 grid blocks), but is reported – within a period of 5 Atlas-years – only from 99 grid-blocks and not from 365×2/3 = 243 grid blocks, i.e. only form 40% of its alleged total (long-term) distribution area. Hence, in the original calculation, a factor 0.40 should have been included: (3000 to 5000) [pairs of Peregrines] x (two third) [of the Peregrine’s range] x 0.4 [99/243 grid blocks] x (one quarter) [of the density of the Peregrine] = 200 to 350 pairs of Grey Falcon.” Penny Olsen has pointed out that the survey effort within the range of the Grey Falcon is far lower than within the range of the Peregrine but even if Jonny Schoenjahn is under-estimating by half the Grey Falcon is a. a very rare bird spread thinly across a large landscape and b. is demonstrably vulnerable to development. It is therefore argued that the precautionary principle can legitimately be applied to this species and that it be listed as Vulnerable D1. The change in status would result from new knowledge (or rather a recalculation based on old knowledge).

Australian Bustard Ardeotis australis: downlist to Least Concern

Garnett and Crowley (2000) argued that the Australian Bustard should be listed as Near Threatened on the basis that it had disappeared from half its historical range, a definition of Near Threatened acceptable at the time. However the population loss in southern Australia occurred before the 3 generation limit (47 years – BirdLife International unpubl. data) and the population in north is now relatively stable and there is no suggestion that there have been any declines in the last half century. While local scarcity can occur, possibly caused by hunting or fire, the population almost certainly exceeds 10,000 mature individuals and has an enormous EOO and AOO. The species therefore does approach any of the thresholds for classification as Vulnerable. The change in status would result from changes in the rigour with which the Near Threatened category is now applied.

Bush Thick-knee Burhinus grallarius: downlist to Least Concern

Garnett and Crowley (2000) argued that the Bush Thick-knee should be listed as Near Threatened on the basis that it had disappeared from half its historical range, a definition of Near Threatened acceptable at the time. Most of the ongoing population loss in southern Australia occurred before the 3 generation limit (31 years, Birdlife International unpubl. data). The population in northern Australia, including many areas where the introduced fox Vulpes vulpes is common, is large with no suggestion of decline. The species is not only common away from settled areas but is common in all cities and towns across northern Australia despite depredation from feral and domestic cats and dogs. The population almost certainly exceeds 10,000 mature individuals and has an enormous EOO and AOO. The species therefore does approach any of the thresholds for classification as Vulnerable. The change in status would result from changes in the rigour with which the Near Threatened category is now applied.

Hooded Plover Thinornis rubricollis:  uplist to Vulnerable

The Hooded Plover is currently classified as NT A2ce+3ce+4ce, C1 because it has a small population, which is suspected to be declining moderately rapidly. Based on monitoring of both eastern and western subspecies it has been determined that the population numbers fewer than 10,000 individuals and a decline of 10-20% is likely in the next 3 generations (20 years) based on monitoring and would thus be eligible for uplisting to Vulnerable under criterion C1. The suggested change in status is a result of better knowledge of western populations. The rate of decline has not and is unlikely to exceed 30% in three generations so it does not meet criterion A, and the EOO and AOO are too large to be considered under B.

Black-breasted Button-quail Turnix melanogaster: downlist: to Near Threatened

Currently listed as Vulnerable B1ab(ii,iii,iv,v), an expert panel recently estimated all IUCN Red List parameters for this species based on advice from local experts and published data. They concluded that the species more closely met the criteria for Near Threatened B1ab(i,ii,iii,iv,v)+B2ab(i,ii,iii,iv,v). The committee believe that, while the Extent of Occurrence and Area of Occupancy are contracting and are both smaller than the threshold for Vulnerable, there is great doubt about whether the criteria B1a or B2a are met, i.e. that the populations are either highly fragmented (>50% of the population in non-viable subpopulations) or that they occurred in 10 or fewer locations. The change in status results from new knowledge: fragmentation of subpopulations is now considered less likely.

Chestnut-backed Button-quail Turnix castanotus: downlist to Least Concern

Garnett and Crowley (2000) argued that the Chestnut-backed Button-quail should be listed as Near Threatened on the basis that it had disappeared from half its historical range, a definition of Near Threatened acceptable at the time. They based this largely on Barnard’s collection of the species from near Borroloola in 1913, a place where it has never been seen since (along with Partridge Pigeon, Hooded Parrot and Northern Shriketit). No recent declines have been reported even though the population is sparse and scattered, certainly population declines in the last 3 generations (10 years) are unlikely and not likely in the next decade. The change in status would result from changes in the rigour with which the Near Threatened category is now applied.

Norfolk Island Parakeet Cyanoramphus cookii: uplist to Critically Endangered

Norfolk Island Parakeet is currently listed as Endangered D on the basis that vigorous and sustained conservation had rescued it from the edge of extinction and the species now had a secure and stable population but which numbered fewer than 250 mature individuals. However the effort to recover species appears to have been relaxed. Monitoring has ceased but anecdotal reports suggest reduced numbers of sightings and high levels of feral cat predation. The population could be <50 but this is uncertain. Given the ignorance about the population and trends and the tiny size of the population there is a good argument that the species should be uplisted to CR B1ab(iii,v)+2ab(iii,v), C2a(ii) given that the population occurs in a single tiny area, may number <250 mature individuals, is in one subpopulation and may be declining as a result of feral cat Felis catus and black rat Rattus rattus predation. This change in status would be genuine and recent.

Superb Parrot Polytelis swainsonii: downlist to Least Concern

Superb Parrot is currently classified as Vulnerable under criterion C2a(ii), as its population was estimated at 6,500 mature individuals, all within a single subpopulation and inferred to be undergoing a continuing decline.  Recent evidence strongly suggests that the population is well over 10,000 individuals, with no evidence of a continuing decline, and although there are projected declines in nest hollows of 20-29% for one part of the population over the next three generations (19 years), there is not believed to be sufficient evidence of the link between hollow availability and parrot abundance such that the total population could be predicted to decline at a rate approaching 30% in the three generations. The species is consequently likely to be reassessed as Least Concern.

Analysis of current knowledge of the species against the IUCN Criteria by the Birds Australia Threatened Species Committee is as follows:

CRITERION A

We agree entirely that there is a loss of hollow-bearing trees in that part of the range of the parrot on the south-west slopes (though note the submission makes no mention of the trees in which they breed along the Murrumbidgee and Murray which have now been protected from logging). We also accept that tree mortality is difficult to reverse and that newly planted trees will not produce hollows for a long time. The information provided does strongly suggest a continuing decline in mature trees and therefore in hollows over the next three generations (19 years – there has been some argument that this figure is too small but no alternative figure with supporting data has been presented). Attachment B (Manning et al. in prep) does not provide a figure for this, but inspection of the outputs from the modelling suggests a decline from 4 potential nest trees (per what?) to 3 potential nest trees, i.e., a decline of c. 25%. In the Oliver et al. submission a figure of 24-27% is given with ongoing loss after that, and a statement that the figure is likely to be conservative. We note that this is a work in preparation and as yet unpublished and therefore not subject to peer review, but we have no reason to doubt it.

While the total size of the population and its trend is in dispute, all evidence available on population trends over the past three generations suggests stability if not an increase. Therefore a link needs to be shown between hollow availability and breeding success in the future. From what we know of hollow dependent taxa, this is a reasonable link, although the strength of the link is unknown. Whether a 25% reduction in hollow availability translates into a 25% reduction in population size is unknown, but would be doubtful as it requires that all available suitable hollows be used by this or other species and that no suitable hollows be available to some breeding pairs. We note that Davey and Purchase (Davey, C. and Purchase, D. 2004. A survey of the Superb Parrot Polytelis swainsonii and potential nesting tree hollows along roads of the south-western slopes, New South Wales. Corella 28, 1–3. 2004) concluded that hollows were not limiting numbers nesting along roads.

We nevertheless do accept that a significant decline in hollow availability will result in a significant decline in the population size, assuming that the species does not adapt by shifting its breeding range. When this decline commenced/commences and what the rate of decline may be are, however, unknown. An independent panel of experts, using a Delphi process recommended and managed by the Australian Centre for Ecological Risk Assessment and adopting a precautionary approach, concluded that, on the basis of all evidence provided, including that in the submission, any decline is highly unlikely to exceed 25% in three generations, the threshold required for listing as Near Threatened A3. The process is not perfect but there is experimental evidence that there is no better method for avoiding predictable biases in expert evidence.

CRITERION B.

Not applicable: EOO >20,000 km2 and AOO >2,000 km2

CRITERION C

Not applicable: there now seems enough evidence to suggest that the population exceeds 10,000 mature individuals, probably by many thousands. An extrapolation of the average no. birds/site x no. sites x area of sites x area sampled (in Manning et al. 2007) gives a total of 400,000 individuals. While no member of the Australian Threatened Species Committee thought this number likely, they thought it highly unlikely the total could be as low as 10,000. It does not matter that there is no clear consensus on the exact population estimate – there just needs to be a judgement about the probability that the lower bound approaches 10,000 mature individuals. Based on the data available, and even given the uncertainty and date of these and that they were collected for a different purpose, the committee thought this highly unlikely.

CRITERION D

Not applicable: >1,000 individuals; >5 locations

CRITERION E

While the modelling of hollow decline for part of the population does imply a decline, it is not a population viability model for the parrot.

Night Parrot Pezoporus occidentalis: reclassify as Endangered

Currently listed as Critically Endangered D (population suspected to number <50 mature individuals), an expert panel recently estimated all IUCN Red List parameters for this species based on advice from local experts and published data. While there was a high level of uncertainty, they concluded that the species more closely met the criteria for EN B2ab(iii)c(ii,iii,iv), D because that AOO is probably very small (provisionally estimated at 500km2), scattered among few locations and probably fluctuates greatly while the overall condition of the habitat is thought to be declining. This change in status would be based on new knowledge: putative and specimen-based sightings at widely separated sites suggest that a population estimate of <50 mature individuals is untenable.

Rufous Scrub-bird Atrichornis rufescens: uplist to Endangered

Rufous Scrub-bird is currently classified as Vulnerable it has a small range, and has experienced continuing habitat destruction and decline in AOO. The following information is taken from the 2010 Action Plan:

The species occurs in high-rainfall areas above 600 m above sea level in south-eastern Queensland and north-eastern New South Wales. A. r. rufescens occurs in the Gibraltar Ranges, Border Ranges, the northern part of the McPherson Range and in parts of the Main Range, but formerly occurred in lowland habitats of the Rich­mond and Tweed River basins. A. r. ferrieri occurs on Barrington Tops, Hastings Range and in the Dorrigo/ Ebor area. Some subpopulations of A. r. rufescens are thought to have disappeared within the last 2 decades including those at Mt Warning and Spicers Gap. In the early 19th century, the population size was probably about 12 000 pairs, but surveys from 1979–1983 estimated it at about 2500 pairs, A. r. rufescens numbering 730 pairs and A. r. ferrieri 1720 pairs at a density of about 6 pairs/ km2 (Ferrier 1984). Declines are suspected in both sub­species (Ekert 2005); A. r. rufescens because of a loss of sus­pected subpopulations (T. Holmes in litt.), A. r. ferrieri because of a reduction in area occupied by calling males in New England National Park (Garnett and Crowley 2000).

Eucalypt forest habitat, which supports the majority of the population and buffers wetter refuges, is potentially threatened by wild fires in dry periods (Ferrier 1984). Declines in density may also occur naturally as vegeta­tion matures and ground cover provides less shelter, so some fire or other disturbance such as storms is helpful as the recovering habitat is readily used by the birds. In the longer term, however, the viability of the small remaining populations may be questionable. Most of the bird’s lowland habitat was cleared in the 19th century, and, while clearance itself is not a continuing threat with almost all birds being in protected areas, the subdivision of a small population into even smaller fragments makes each subpopulation more susceptible to random events.

With an Area of Occupancy estimated at 410 km2, suspected to be severely fragmented, undergoing a continuing decline in AOO, number of locations, and mature individuals, it is proposed that the species be uplisted to Endangered under criterion B2ab(ii,iv,v).

Noisy Scrub-bird Atrichornis clamosus : uplist to Endangered

In 2000 the Noisy Scrub-bird was listed as Vulnerable D2 following several decades of dedicated and successful conservation management. Sadly a lightning-lit fire in the largest population that could not be contained demonstrated that this change was premature and that sudden changes in population can occur at any time – or at least in any long hot summer. Until more sites are established the species probably fits more closely EN B1ab(iii,v)+2ab(iii,v), C2a(i), having a very small population restricted to a very small EOO and AOO at very few locations. The recent series of large wildfires and some unexplained smaller-scale declines suggests a probable continuing decline in habitat quality and number of mature individuals. Genuine change: fires reversed recovery and cannot be halted in the future despite management.

Short-tailed Grasswren Amytornis merrotsyi: uplist to Near Threatened

Short-tailed Grasswren is currently classified as Least Concern, however its Area of Occupancy (recently estimated at 1,100 km2) meets the threshold for classification as Vulnerable, it occurs at a moderately small number of locations (currently estimated at 17), and fires are believed to have become more extensive and more frequent in recent years, causing a continuing decline in AOO, habitat quality and number of mature individuals. It is thus proposed that this species be uplisted to Near Threatened under criterion B2ab(ii,iii,v).

Carpentarian Grasswren Amytornis dorotheae: downlist to Near Threatened

Carpentarian Grasswren was recently uplisted to Vulnerable as its population was thought to number fewer than 10,000 mature individuals and was estimated to be undergoing a continuing decline of at least 10% in three generations.

Data gathered for the Action Plan gives a revised estimated total population numbering 14,000 mature individuals, of which over 90% (13,000) are in the largest of the three subpopulations. The species is inferred to be undergoing continuing declines as a result of increased fire frequency and severity, and is suspected to have declined by 20-29% in the last 3 generations (now estimated at 29 years). It is consequently proposed to reclassify the species as Near Threatened, nearly meeting criteria NT A2c, C2a(ii).

Black Grasswren Amytornis housei: uplist to Near Threatened

This species is currently classified as Least Concern as although it has a restricted range it was not thought to approach the other criteria for classification as Vulnerable (declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation).  While the actual records of this species are from far smaller areas than the EOO and AOO thresholds of 20,000 km2 and 2,000 km2 respectively, they are sufficiently scattered to suggest that there are many undetected individuals. Nevertheless the total EOO and AOO may not be much greater than these thresholds and in the last decade there have been repeated fires through its range in the Kimberley. While parts of its range are naturally protected by the extremely rugged terrain that breaks up fire and protects the old spinifex Triodia spp., the increase in the extent and frequency of fire is almost certainly reducing the EOO, AOO, habitat suitability and population of this species. The number of locations for the species, currently assumed to be more than 10, may also be becoming smaller. A Near Threatened status under criteria B1ab(i,ii,iii,iv,v) +B2ab(i,ii,iii,iv,v) is proposed. The reason for change would be that there has been a real increase in fire extent and frequency in the Kimberley which is inferred to be driving continuing declines in EOO, AOO, quality of habitat, number of locations and number of mature individuals.

Western Bristlebird Dasyornis longirostris: uplist to Endangered

Western Bristlebird is currently classified as Vulnerable under criterion C2ai, D2 as it has a very small range, and a small population which is undergoing a decline, owing mainly to the effects of wildfires. The following information is taken from the 2010 Action Plan:

Range: Currently occurs east of Albany at Two Peoples Bay Nature Reserve, Betty’s Beach, Mt Manypeaks to Bluff Creek, and at 14 different sites in and near Fitzgerald River National Park (Gilfillan et al. 2009). Historic records of the Western Bristlebird suggest that it occurred in coastal areas from Perth to Augusta and from Albany to Fitzgerald River National Park, Western Australia (Cale and Burbidge 1993). Eighteen birds were translo­cated in 1999–2000 and 2007 from Two People’s Bay to near Walpole, west of Albany, but there was no evidence of breeding (Burbidge 2003; Gilfillan et al. 2009; Bur­bidge et al. 2010).

Abundance: A population of c.620 pairs in 2001 was reduced by fires to c.320 pairs in 2005 (Burbidge et al. 2010); here esti­mated as 1000 mature birds. The density of birds is greater in the Manypeaks-Waychinicup areas than in the Fitzger­ald River National Park, but reasons for this are unknown. The Albany to Mt Manypeaks area population declined from c.500 pairs in 2001 to 200–315 pairs in 2005 and 2006, largely as a result of wildfires, although the cause

for the decline in some areas is unclear (Comer and McNee 2001; Tiller et al. 2006). The Fitzgerald River National Park subpopulation numbered c.125 pairs in 2005 (Burbidge et al. 2010). At the time of assessment, the total population was considered not to be declining over a timescale of 3 generations (16 years), but an increasing risk of wildfires was considered to be probably causing a continuing decline in habitat quality.

Threats: Fire is the main current threat, with fires at less than 5–10 year intervals leading to local extinction (Smith 1987). At the other end of the scale, coastal heath (at least at Two Peoples Bay) remains suitable habitat for at least 60 years after fire, though carrying capacity may be reduced with time (Smith 1987; A. H. Burbidge in litt.). The incidence and extent of wildfires have been increasing in recent years, despite increased skills, capacity and effort to stop them. Given that fire is the main threat, locations are defined as being independent during massive wildfires; here estimated to be <5.

Data gathered for the Action Plan gives an Extent of Occurrence of <5,000 km2, and estimates five locations for the species, with the recent series of large wildfires suggesting a probable continuing decline in habitat quality, suggesting that the species should be uplisted to Endangered under criterion B1ab(iii).

Norfolk Island Gerygone Gerygone modesta: downlist to Near Threatened

Although the Norfolk Island Gerygone occurs at only one location, Norfolk Island, it remains common and widespread there. Unlike its close relative on Lord Howe Island, it has not succumbed to introduced Black Rats Rattus rattus and nor has it been unduly affected by changes in habitat or the other introduced animals and plants that have afflicted some other Norfolk Island taxa. As no credible threat likely to rapidly drive the species to CR or EX is apparent, VU D2 seems no longer to be applicable under more rigorously applied IUCN Red List guidelines and it is proposed that the species is downlisted to Near Threatened (criterion D2), occurring at a single small location and potentially susceptible to the effects of invasive predators, competitors or disease, but with no plausible threat likely to lead to a very rapid decline.

Regent Honeyeater Xanthomyza phrygia: uplist to Critically Endangered

Gallant efforts to save the Regent Honeyeater have not yet demonstrated success. Previously listed as EN C2a(ii), the population has been inferred from monitoring to have undergone a decline of >80 in the past 24 years (three generations), which means it should be CR A2b. In 2010 there was just one nest found in what is now the major known breeding site of Capertee Valley. While this may improve in a less unusual year than this one, when there is little flowering in the valley and much flowering elsewhere, it would be dangerous to assume so given the low overall population estimate. Therefore the reason for change would be real because numbers being monitored have declined substantially in the last decade.

Western Whipbird Psophodes nigrogularis: downlist to Least Concern

Western Whipbird is currently classified as Near Threatened as it was thought to have a moderately small population, divided into four subpopulations, with the overall population trend unknown, but it likely to be fluctuating locally owing to the impacts of wildfires. Data gathered for the Action Plan suggests that several subpopulations contain more than 1,000 individuals, (with large subpopulations including 5,000 P. n. leucogaster on the Eyre Peninsula and 2,000 P. n. lashmari on Kangaroo Island). P. n. oberon in southwest Western Australia is now believed to number 5,000 individuals, and the total population of the species is undoubtedly over 10,000 mature individuals. Consequently the species is not believed to approach the thresholds for classification as Vulnerable under C2aii, nor does it approach the thresholds for any of the other Red List criteria. It is therefore proposed to downlist the species to Least Concern.

Red-lored Whistler Pachycephala rufogularis: uplist to Vulnerable

The Red-lored Whistler was listed as NT C2a(i)  because numbers were thought to be <10,000 and declining but the distribution of the population was such that it did not meet either C2a(i) or C2a(ii) criteria for Vulnerable. Sadly there has been contraction in range and loss of suitable habitat within existing populations in the last decade such that it now seems to meet the criteria for Vulnerable B2ab(i,ii,iii,iv,v), C2a(i). having an AOO estimated at 500 km2, and occurring at ten locations, with increased fire frequency believed to be driving continuing declines in EOO, AOO, habitat quality, no. locations and no. mature individuals. Large fires in Round Hill and Book Mark Biosphere Reserve  have reduced largest subpopulations and the species has not been seen on Eyre Peninsula in 10 years despite searching. The largest subpopulation, at Bookmark, is now assumed to be <1,000 and the total population <10,000 mature individuals.

Slender-billed White-eye: Zosterops tenuirostris: downlist to Near Threatened

In the 2000 Action Plan the status of this species was assessed as EN B1ab(ii,iv,v); B2ab(ii,iv,v); C2a(ii) because it was feared that the bird was being seen less frequently so, given the small EOO and AOO, a small, declining population was assumed. However, although it has declined historically through habitat clearance, the population now seems to have been stable at a single site for some decades. Unlike its close relative on Lord Howe Island, it has not succumbed to introduced Black Rats Rattus rattus and nor has it been unduly affected by changes in habitat or the other introduced animals and plants that have afflicted some other Norfolk Island taxa. As no credible threat likely to rapidly drive the species to CR or EX is apparent, VU D2 seems no longer to be applicable under more rigorously applied IUCN Red List guidelines and it is proposed that the species is downlisted to Near Threatened (criterion D2), occurring at a single small location and potentially susceptible to the effects of invasive predators, competitors or disease, but with no plausible threat likely to lead to a very rapid decline.

Christmas Island White-eye: Zosterops natalis: downlist to Near Threatened

Christmas Island White-eye is currently classified as Vulnerable under criterion D2, being restricted to two small locations and thought to be susceptible to the effects of introduced taxa.  However, the population has apparently remained stable despite the well-documented arrival of invasive Yellow Crazy Ants (in fact counts of the white-eye are higher in place where the ants are present). Black Rats are present but there is no indication that they are affecting numbers of Z. natalis. Further introductions of invasive species or diseases are possible threats, but there is not thought to be any plausible threat likely to rapidly drive the species to CR or EX. Vulnerable (D2) seems no longer to be applicable under more rigorously applied IUCN Red List guidelines and it is proposed that the species is downlisted to Near Threatened (D2), occurring at two small locations and potentially susceptible to the effects of invasive predators, competitors or disease, but with no plausible threat likely to lead to a very rapid future decline.

Black-throated Finch Poephila cincta: downlist to Least Concern

Black-throated Finch is currently classified as Near Threatened as it was suspected to be undergoing a moderately rapid population decline. Information gathered for the Action Plan suggests that although there has been a marked decline in reporting rate suggesting declines, overall declines are well below 30% in three generations (10 years) and no other criteria are close to being met. It is therefore proposed to downlist the species to Least Concern.

Star Finch Neochmia ruficauda: downlist to Least Concern

Star Finches are patchily distributed across northern Australia. The southern subspecies may have disappeared, with the last good sighting about 16 years ago. However the small Cape York Peninsula populations seem stable for the moment (reporting rate went up because people went looking for it) and the flocks in the Victoria River District and the Ord River Irrigation Area are large and widespread and show no signs of declining because the wet season protects their breeding sites from grazing. The species also persists in the Pilbara. Thus, with the apparent loss of ruficauda in Qld, the rates of decline appear to have slowed to an extent that they cannot be said to be approaching the 30% threshold- the population is believed to have been relatively stable over the past three generations, and, having a large range and population the species no longer approaches the relevant thresholds under any of the Red List criteria.  It is thus proposed to downlist the species to Least Concern.

Diamond Firetail Stagonopleura guttata: downlist to Least Concern

Garnett and Crowley (2000) argued that the Diamond Firetail should be listed as Near Threatened on the basis that it had disappeared from half its historical range, a definition of Near Threatened acceptable at the time. However, although there have been declines, they do not approach 30% in 10 years (3 generations is shorter than 10 years). Also the population is likely to be much greater than 10,000 mature individuals and the EOO and AOO far exceed the 20,000 km2 and 2,000 km2. The change in status would result from changes in the rigour with which the Near Threatened category is now applied.

Gouldian Finch Erythrura gouldiae:  downlist to Near Threatened

In 2000 the status was listed as EN C2a(ii) on the basis that the population size of this species was conservatively estimated to be about 2,500 mature individuals at the start of breeding season, with all individuals in the same genetic sub-population and continuing to decline (Endangered: C2a(ii)). If the population was significantly fragmented, then no sub-population indisputably contains more than 250 mature individuals (so could be C2a(i)).

In late 2010 an expert panel estimated all IUCN Red List parameters for this species based on advice from local experts and published data. They determined that the most appropriate status should be NT D1: although well below historical levels, the population appears to have stopped declining but may contract to near 1,000 mature individuals at the end of the dry season.

Please see the attached file containing a summary of the discussion on this species.

Gouldian Finch Erythrura gouldiae

References

Garnett, S. T. and Crowley, G. M. (2000) The action plan for Australian birds 2000. Canberra: Environment Australia.

Garnett, S.T., Szabo, J. and Dutson, G. (2011). Action Plan for Australian Birds 2010. CSIRO, Melbourne.

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One Response to Archived 2011-2012 topics: Proposed revisions to Australian endemics based on reassessments in The Action Plan for Australian Birds 2010

  1. Mark O'Brien says:

    Just a comment. Guy Dutson surveyed for White-chested White-eye on NOrfolk Island, but recorded encounters with other species while doing the point counts. He recorded Norfolk Island Parakeet on 13 occasions, and estimated total population at 240 individuals. He states in the discussion
    “The Tasman Parakeet is categorised as globally Endangered (D1) because its population was last estimated, in 2004, to be only 200-300 individuals (BirdLife International 2009). This estimate was noted to be very approximate given the difficulty of surveying the species outside the National Park (R. Ward in litt. 2005 in BirdLife International 2009). The 2009 survey under-estimated numbers (see Table 1) but estimated a minimum of 240 birds within the National Park. Parks Australia has calculated that the population could be 200 birds based on the survival and longevity of birds known to have fledged from monitored nest sites (C. Rowston pers. comm. 2009). The threshold for Endangered status under category D1 is 250 adult birds. This survey supports previous estimates that the species may now have recovered past this threshold but a dedicated survey across the island is needed to improve the accuracy of the estimate. ”
    Appreciate its a bit late now as you’ve closed the thread. But thought it was worth flagging up in the event of the next review.

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