Current view: Data table and detailed info
Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
full migrant |
Forest dependency |
does not normally occur in forest |
| Land-mass type |
|
Average mass |
59 g |
Population justification: Lane (1987) estimated the minimum number of individuals to be 12,450, based on the maximum observed simultaneous counts in New Zealand and Australia in the mid-1980s. The population of C. b. exilis in the Auckland Islands was estimated to number 730 birds in 1989 (Walker et al. 1991). There is no more recent population data on this subspecies.
Heather and Roberton (1996) estimated the population size to be c.50,000 individuals, based on banding studies, with c.30,000 (60%) wintering in Australia. Pierce (1999) considered that the population probably exceeded 50,000 individuals, based on estimates of the wintering population in Tasmania, data from breeding grounds and proportions of colour-banded individuals seen at non-breeding sites (Dowding and Moore 2006).
During extensive surveys of estuaries around the New Zealand coast between 1983 and 1994, Sagar et al. (1999) counted a maximum of 9,242 birds during winter (with similar numbers reported in the North and South Islands), leading to a New Zealand winter population estimate of 10,843 individuals. The low counts were attributed to the lack of surveys inland, where large numbers overwinter. During similar winter coastal surveys in New Zealand from 1994 to 2003, total counts ranged from 2,759 to 6,296, with an average of 4,546 (Southey 2009). Winter population estimates of 5,083 - 7,335 between 1995 and 2004 were derived, with an estimate of 5,406 individuals for 2003 (Southey 2009). These figures were thought to represent underestimates of the true New Zealand wintering population, since some moderately important overwintering sites were not included in the surveys, but the total winter population in New Zealand was thought unlikely to be as high as 20,000 individuals (Southey 2009).
The population in the Chatham Islands has been estimated to be around 200-300 individuals (Aikman and Miskelly 2004).
Based on count data from 2005/2006 to 2014/2015, the global population was estimated to be 13,057 individuals based on counts alone, 18,786 based on spatial extrapolations, and 19,559 based on range area and density estimates, with a final rounded population estimate of 19,000 (Hansen et al. 2016).
Counts of breeding individuals on braided rivers in the South Island New Zealand from 1962–2017 recorded a total of 12,730 birds (O'Donnell and Monks in press).
The population size is here placed in the band 13,057 - 19,559 individuals, here rounded to 13,000 - 20,000 individuals. This is assumed to roughly equate to 8,705 - 13,039 mature individuals, here rounded to 8,000 - 14,000 mature individuals. The best estimate is 19,000 individuals (Hansen 2016), which is assumed to equate to 12,667 mature individuals, here rounded to 13,000 mature individuals.
The number of subpopulations is not known. Although different parts of the population have different migration strategies, not all birds from an area migrate to the same wintering grounds, and there may be gene-flow between regions due to juvenile dispersal (J. Dowding in litt. 2019).
Trend justification: The population size is believed to be declining (Hitchmough et al. 2005, Dowding and Moore 2006, Miskelly et al. 2008, Robertson et al. 2012), and the species has disappeared from sites where it previously bred across New Zealand (Pierce 2013). In Australia, atlas surveys in 1977-1981 and 1998-2001 indicated a decline in wintering range (Barrett et al. 2002, Department for the Environment 2020).
The population in the Auckland Islands was estimated to number 730 birds in 1989 and was thought to be increasing as a result of an increase of breeding habitat produced by fire and introduced grazing mammals (Walker et al. 1991). However, grazing mammals have since been removed fom Enderby Island, which may have led to a decline in breeding habitat (Dowding and Murphy 2001). There have been no more recent surveys in the Auckland Islands.
Surveys in the Upper Waitaki Basin in the South Island found that the species's population density declined between 1962-1968 and 1991-1994 on seven out of nine rivers, with an average overall density change of 8% (Maloney 1999). Scaled over three generations (13 years), this would equate to an average reduction of c. 4%. Local breeding populations have been lost from several sites, and large declines have been reported between the 1940s and the 1980s in the numbers of birds wintering at some sites (Dowding and Moore 2006). A comparison of individuals counted at the same New Zealand coastal sites during winters in 1984-1994 and 1994-2003 indicated a decline of 16% (Sagar et al. 1999, Southey 2009). This would equate to a 20% reduction over three generations (13 years). Trends in individual sites varied, with counts increasing by up to 39% at some sites, and declines of up to 83% observed at other sites (Southey 2009). Winter population estimates declined sharply in the mid-late 1990s, and appeared to remain relatively stable from the late 1990s to 2003, with (incomplete) winter population estimates of 7,335 in 1994 and 5,406 in 2003, indicating a 26% decline (Southey 2009), which would equate to a 36% reduction over three generations (13 years). Surveys in the Ashley River, Canterbury, showed an increase in breeding individuals between 1963 and 2011, with a significant increase between 2000 and 2015 (Spurr and Ledgard 2015).
In Australia, the maximum count of wintering birds in the early 1980s was c.5,600 birds in 1985 (Lane 1987), and the maximum count in the early 2000s was 2,799 birds in 2002 (Skewes 2003). Counts of wintering birds at Corner Inlet, Victoria, Australia, from 1982 to 2011, found a non-significant annual increase of 1.3%, with a mean abundance of 552 individuals and large annual fluctuations (Minton et al. 2012). The 2019 Australian Waterbird Index, which reviewed available Australian waterbird data up to 2017, suggests a population decline in the late 1990s, an increase in the 2000s, and a small decline since c.2012 (Clemens et al. 2019). Overall, it reported a declining long-term trend (since the 1980s), an increasing medium-term trend (over 21 years) and a flat short-term trajectory (Clemens et al. 2019). It does not indicate a reduction in the Australian wintering population over the past three generations since 2007.
The New Zealand Threat Classification System has listed the subspecies C. b. bicinctus as Nationally Vulnerable since 2008, based on a predicted or ongoing decline of 30-70% over three generations (Miskelly et al. 2008, Robertson et al. 2012, 2017), but the basis of this estimate is not provided. A review of trends in the counts of breeding individuals on 33 South Island braided rivers from 1962–2017, with >50% of counts made on ten rivers, found an overall mean decline 3.7% per year (O'Donnell and Monks in press), which would equate to a reduction of 39% over three generations (13 years). The authors also found a decline in New Zealand winter counts, at a rate of 1.4% per year (O'Donnell and Monks in press), which would equate to a reduction of 17% over three generations (13 years).
According to O'Donnell and Monks (in press), data on breeding individuals in South Island rivers suggests that the species may have undergone a reduction of 39% over three generations. However, it is unclear whether these trends are representative of the whole population. Data on wintering birds in Australia, which may represent c.60% of the global population, did not indicate a population reduction over the past three generations (13 years; Clemens et al. 2019), whilst data on wintering birds in New Zealand, which is assumed to represent up to 40% of the total population (although it does not include the populations in the Auckland and Chatham Islands), indicated a decline of 17% over three generations (O'Donnell and Monks in press). Taken together, this information on the Australian and New Zealand populations indicates a reduction of c.7% over the past three generations. The reduction over the past three generations is here placed in the band 7-39%, with a best estimate tentatively placed in the band 7-29%. Trends are assumed to continue at a similar rate over the next three generations.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Double-banded Plover Charadrius bicinctus. Downloaded from
https://datazone.birdlife.org/species/factsheet/double-banded-plover-charadrius-bicinctus on 25/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 25/12/2024.
