St. Helena Plover Anarhynchus sanctaehelenae Scientific name definitions

Ca. 15 cm. Resembles Kittlitz's Plover (Anarhynchus pecuarius) , but larger, with longer bill and longer “wiry” legs  (up to 40% longer); less buff on breast  and on feather fringes of upperparts ; black lines do not meet on nape. Sexes alike. No seasonal variation. Juvenile has dull brown head pattern, without black areas on head and neck; crown and upperpart feathers narrowly fringed pale buff.

Probably most closely related to Madagascar Plover (Anarhynchus thoracicus) and Kittlitz's Plover (Anarhynchus pecuarius); often considered conspecific with latter. Monotypic.

St Helena, in southern Atlantic Ocean.

Widespread, particularly in flatter, more open upland habitats at medium elevations (to above 500 m) (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ), and around edges of island. Forages on hot stony plains with wire-grass (Cynodon dactylon) and eroded areas of kaffir fig (Carpobrotus edulis); also upland pastures, especially when recently grazed by cattle, plowed fields, and even large, remote vegetable gardens; never occurs on the shore. It has been suggested that, until deforestation at end of 19th century, species may have been woodland (Commidendrum robustum) floor-dweller, although other commentators have suggested that parts of western St Helena might always have supported semi-desert and scrub, and have also noted that the land area of the island was formerly larger, with a more extensive, gently sloping coastal plain (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ).

Sedentary, although young birds may wander widely around the island (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ).

Very poorly known. Insects and snails recorded. Usually seen in pairs, rarely in groups of up to six birds, although newly fledged young may form small flocks of as many as 15 individuals (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ).

Similar to Kittlitz's Plover (Anarhynchus pecuarius) (2 Hayman, P., J. Marchant, and T. Prater (1986). Shorebirds. An Identification Guide to the Waders of the World. Croom Helm, London, UK. Close ). Calls  include a short, soft kee-vit and a rattling sound in alarm. A short trilling call is sometimes heard in flight.

Breeds mainly in drier part of year, late September to January, mainly December–January, possibly varying considerably between years, depending on conditions, with activity recorded year-round (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ). Breeds on quite remote, open plains in northern half of island. Probably solitary and monogamous (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ). Nest is simple scrape lined with dry grass or dry cow dung (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ). Clutch 1–2 eggs (up to three), gray with even darker markings, size 30.3–36.5 mm × 23.6–25.5 mm (3 Pitman, C.R.S. (1965). The eggs and nesting habits of the St. Helena Sand-Plover or Wirebird, Charadrius pecuarius sanctae-helenae (Harting). Bull. Brit. Orn. Club. 85(7): 121–129. Close ), incubated by both sexes, with males mainly incubating at night (4 Burns, F., McCulloch, N., Dos Remedios, N., Bolton, M. and Székely, T. (2013). Sex differences in incubation behaviour but not mortality risk in a threatened shorebird. Ibis. 155(4): 877–880. Close ), for ca. 28 days (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ); can be double-brooded or lay replacement clutch (5 Burns, F., McCulloch, N., Szekely, T. and Bolton, M. (2013). The impact of introduced predators on an island endemic, the St Helena Plover, Charadrius sanctaehelenae. Bird Conservation International. 23(2): 125–135. Close ); chick  buff, streaked black, with gray tinge; fledge at ca. 5 weeks and generally remain within nest territory until this time (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ). Eggs and young taken by feral cats, introduced Common Myna (Acridotheres tristis) and rats (mostly brown rats Rattus norvegicus but possibly also black rats R. rattus) (6 Prater, T. (2012). Important Bird Areas. St Helena. British Birds 105:638–653. Close ), which occasionally form plagues on the island; Common Myna may also be competing for same food resources. Nest success generally very low, just 0.1 young fledge per nest (6 Prater, T. (2012). Important Bird Areas. St Helena. British Birds 105:638–653. Close ), although 39% of 28 nests with known outcome in 1988/89 produced at least one chick, while hatching success was 95% for nests not subject to predation and overall success from egg to fledging was estimated at 19% (1 McCulloch, N. (1999). St Helena Wirebird: the forgotten plover. Bull. African Bird Club. 6(2): 95–99. Close ). More recent research has reported nest survival rates to range from 6% to 47% due to variation in predation levels, with cats shown to predate the largest proportion of nests, being responsible for 65% of predated nests monitored during 2007–2008, followed by rats (15%) and Common Mynas (10%) (5 Burns, F., McCulloch, N., Szekely, T. and Bolton, M. (2013). The impact of introduced predators on an island endemic, the St Helena Plover, Charadrius sanctaehelenae. Bird Conservation International. 23(2): 125–135. Close ). Adult survival is probably high, with no differences recorded between the sexes (4 Burns, F., McCulloch, N., Dos Remedios, N., Bolton, M. and Székely, T. (2013). Sex differences in incubation behaviour but not mortality risk in a threatened shorebird. Ibis. 155(4): 877–880. Close ), but longevity unknown.

VULNERABLE. Only occurs in northern, flatter parts of interior of St Helena; but distribution of species now shifting east, due to expansion of urban areas. Known from 11 separate breeding areas with total population estimated at fewer than 100 pairs in 1952. In late 1960s, species thought to be commoner, a view supported in 1983 by an estimate of several hundred birds. In 1984, species seemed less numerous than ten years before. Intensive survey in 1988–1989 recorded ca. 450 birds; further censuses indicated continuous, steady decline from ca. 375 birds in 1991, to ca. 315 birds in 1993; numbers at a key area, Deadwood Plain, had halved since late 1980s. Fieldwork in 1999–2000 and 2000–2001 suggested populations had stabilized at ca. 350 adults, but survey data from 2005 and 2006 revealed further decline to ca. 235 mature individuals (7 McCulloch, N. (2009). Recent decline of the St Helena Wirebird Charadrius sanctaehelenae. Bird Conservation International. 19(1): 33–48. Close ). Previously considered Endangered or Vulnerable in response to results of population surveys, it was therefore listed as Critically Endangered in 2007, and a ten-year Species Action Plan launched the following year BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 24/04/2017. . Show high rates of nest failure, mainly due to predation by rats (Rattus rattus and R. norvegicus), Common Myna (Acridotheres tristis) and especially cats (5 Burns, F., McCulloch, N., Szekely, T. and Bolton, M. (2013). The impact of introduced predators on an island endemic, the St Helena Plover, Charadrius sanctaehelenae. Bird Conservation International. 23(2): 125–135. Close ). Nest exclosures, designed to prevent predation by cats, have been trialled, but clutch survival proved similar between nests with and without cages, and exclosures may have increased adult mortality (8 Burns, F., McCulloch, N., Székely, T. and Bolton, M. (2013). No overall benefit of predator exclosure cages for the endangered St. Helena Plover Charadrius sanctaehelenae. Ibis. 155(2): 397–401 Close ). Live-trapping of cats has increased nesting success threefold in semi-desert areas, but increased only marginally in pastures (perhaps due to increased rat activity and potentially rat predation following cat control in pastures, whereas no increase in rat activity was observed in semi-desert) (9 Oppel, S., Burns, F., Vickery, J., George, K., Ellick, G., Leo, D. and Hillman, J.C. (2014). Habitat-specific effectiveness of feral cat control for the conservation of an endemic ground-nesting bird species. Journal of Applied Ecology. 51(5): 1246–1254. Close ). Sheep also disturb nests BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 25/03/2015. . Nevertheless, species appears to be reasonably safe unless breeding areas are affected. As a result of conservation interventions, annual censuses in 2007–2010 averaged 353 adults, with 350 recorded in 2011 BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 24/04/2017. ; most recent count in 2016 recorded 559 mature individuals and the species was downlisted to Vulnerable in 2016 BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 24/04/2017. . An airport was constructed at one breeding site in semi-desert at Prosperous Bay, but associated developments to include additional housing, roads, hotels and a golf course have not materialized BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 24/04/2017. . Most important breeding site at Deadwood Plain, which hosts 20% of breeding population, has been earmarked for significant wind turbine development BirdLife International (2015) Species factsheet: Charadrius sanctaehelenae. Downloaded from http://www.birdlife.org on 25/03/2015. . All bird species on St Helena protected by law since 1894.