Justification of Red List category
This species has been uplisted to Vulnerable because it has a small population, which has been estimated through monitoring to be undergoing continuing declines of over 10% in three generations (39 years). Declines in eastern Australia are caused by reduced breeding success as a result of disturbance by people, dogs and horses, as well as predation by introduced foxes and native gulls and corvids that have increased as a result of human activity; in Western Australia declines are less marked and driven by habitat degradation arising from cattle grazing and water abstraction for agriculture.
The numbers of mature individuals are 3,000 cucullatus and 4,000 tregellasi. This gives a total population size of 7,000 mature individuals.
Ongoing population declines of 10-25% in 3 generations have been recorded in all eastern states based on monitoring and, while monitoring in the west has been less rigorous, it suggests ongoing declines which contribute to an overall decline of >10% for the whole species (Garnett et al. 2011).
Thinornis cucullatus is endemic to Australia and is found in Western Australia, South Australia, New South Wales, Queensland (vagrant), Tasmania and nearby islands. The eastern subspecies cucullatus is restricted to the coastline and numbers 3,000 birds (Garnett et al. 2011). Its range has contracted in Queensland and New South Wales, and declines, probably driven by low reproductive success, have been estimated based on monitoring data in all eastern states (Garnett et al. 2011). Calculated population declines include 12% across Victoria from 2000–2008, and 33% from 600 to 400 from 1980–2008 (Birds Australia 2008); 13% between comprehensive surveys across Victoria in 1988 and 1992, but statistically non-significant overall decline 1980–1992 (Weston 1993); 58% on Phillip Island from 1981–1997 (Baird and Dann 2003); c.20% across Tasmania from 1982–2006 (Woehler and Park 1997, Bryant 2002 and E. J. Woehler in litt., in Garnett et al. 2011); 25% on Kangaroo Island from 1985– 2004 (Dennis and Masters 2006, in Garnett et al. 2011); and 55% across New South Wales from 1988–2008 (Birds Australia 2008; NSW Scientific Committee 2008). The declines in New South Wales and Kangaroo Island may be biased towards heavily-disturbed beaches. Though largely secure on small islands, it is likely to continue declining wherever appropriate beach management is lacking (Weston 1993). The western subspecies tregellasi numbers 2,500 birds (Garnett et al. 2011). This population has been subject to less rigorous monitoring but the data available suggest that it may also be in decline.
The species primarily inhabits sandy, ocean beaches, with the highest densities on beaches with large amounts of beach-washed seaweed, that are backed by extensive open dunes (Schulz and Bamford 1987). In Western Australia the species also inhabits inland and coastal salt lakes (Schulz and Bamford 1987). In eastern Australia, it is an opportunistic feeder and takes a range of invertebrates; in Western Australian salt lakes, it eats the gastropod Coxiella spp. (Weston 2007). In Victoria, breeding territories have more prey items than areas where breeding does not occur (Cuttriss et al. 2015). The species shows a preference for nesting on flat beaches, in some places on stony terraces (Baird and Dann 2003) and often in primary and secondary sand dunes (Schulz and Bamford 1987, Baird and Dann 2003). It lays 1-3 eggs (usually 3) (Schulz and Bamford 1987, Baird and Dann 2003). In eastern Australia, clutches are laid from August to February (Schulz and Bamford 1987) or March (Baird and Dann 2003). Most on Phillip Island are laid from December to February, with the peak in January (Baird and Dann 2003). Unlike most other birds, cucullatus moult their primary feathers while breeding (Rogers et al. 2014). Hooded Plovers are highly dispersed nesters with relatively large territory sizes (37 ha) to which they are highly site faithful (Weston et al. 2009). In Western Australia the breeding season is less well defined, and some birds may nest semicolonially (M. Weston in litt. 2016).
The greatest threat to this species is low breeding success and thus low recruitment (Weston 1993). The primary causes of nesting failure are the crushing of nests and eggs by off-road vehicles and trampling by livestock and people (Schulz and Bamford 1987, Weston and Morrow 2000, Weston 2001, Baird and Dann 2003), disturbance by people and their dogs (Baird and Dann 2003, Weston and Elgar 2005, 2007), flooding by spring tides, predation (Schulz and Bamford 1987), and ill-considered beach erosion management (Weston and Morrow 2000, Weston 2001). Up to 81% of nests and 30% of chicks in the Coorong would have been crushed by off-road vehicles (Buick and Paton 1989), and over 30% of nests were trampled by dogs or people at Mornington before controls were introduced (Dowling and Weston 1999). The species's breeding season coincides with the peak in the summer holiday season, when human presence on beaches is at its highest (Schulz and Bamford 1987, Baird and Dann 2003). Festival and beach events can constitute major localised threats (M. Weston in litt. 2016). Human disturbance increases the likelihood of predation and thermal stress (Schulz and Bamford 1987, Weston 2000). Human disturbance increases the likelihood of predation and thermal stress (Schulz and Bamford 1987, Weston 2000). On the mainland, predation by foxes, cats and dogs is considered one of the most significant threats. The introduction of foxes to Tasmania may threaten the population in this stronghold and introduced predators may now be a problem on Kangaroo Island, another refuge for the species (M.A. Weston in litt. 2007). Around human settlements, artificially high numbers of Silver Gull Larus novaehollandiae and corvids Corvus spp. sometimes prey on eggs and chicks (M. A. Weston in litt. 2016). Water rats and Australian magpies may also prey on some eggs and chicks. Ongoing development is opening up areas of coastline to human activities and further developments (M.A. Weston in litt. 2007). Oil-spills represent an additional threat (Weston 2003). Birds remain relatively secure on islands and where active nest protection operates; however, on Phillip Island, declines between 1982 and 1998 suggest that breeding success was too low to sustain the local population, probably due to anthropogenic causes of nest failure (Baird and Dann 2003). The species's coastal habitats are threatened with degradation by marram grass Ammophila arenaria and other introduced coastal weeds (M. A. Weston in litt. 2007). The population in Western Australia is considered to be in less danger because, in addition to beaches, it breeds on inland and coastal salt lakes where human disturbance events are rare (Schulz and Bamford 1987), especially in remote areas. Depredation by foxes is probably the main threat in Western Australia, but it is not known whether this constrains the population. Pollution and altered hydrology of lakes may also affect the western population (M. A. Weston in litt. 2016).
Conservation Actions Underway
Significant ongoing research is being carried out into the management of this species (Weston 2001, Dodge et al. 2003, Maguire et al. 2009, 2011). There are already regular surveys of this species, and detailed studies into its breeding biology have been ongoing. Effective beach-sharing protocols have been developed. Cages have been used successfully to protect nests, although the risk of adult mortality may mean that the idea is abandoned (M. A. Weston in litt. 2007). An Action Statement has been prepared for its conservation in Victoria. A draft Recovery Plan has been prepared for New South Wales and South Australia. Baiting of foxes in some areas of Western Australia is reducing predation.
Text account compilers
Benstead, P., Butchart, S., Dutson, G., Garnett, S., McClellan, R., Symes, A. & Taylor, J.
Crowley, G., Garnett, S. & Weston, M.
BirdLife International (2023) Species factsheet: Thinornis cucullatus. Downloaded from http://datazone.birdlife.org/species/factsheet/hooded-plover-thinornis-cucullatus on 26/09/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 26/09/2023.