Saint Helena is a remote tropical island located in the South Atlantic Ocean. The volcanic island has an area of 121 km2 and an estimated population of 4,534. Saint Helena, along with Ascension Island and the Tristan da Cunha chain of islands, form the British Overseas Territory (BOT) of Saint Helena, Ascension and Tristan da Cunha. Although Saint Helena is not a country, it has a national bird: the Saint Helena plover.
The Saint Helena plover (Charadrius sanctaehelenae), which is featured on the island's coat of arms and coins, is a species of wader, and is known locally as the "wirebird" due to its long, wiry, thin legs. The plover is the only surviving bird species endemic to Saint Helena, although its population is declining. In fact, a study conducted in 2006 revealed that the Saint Helena plover's population was less than 200, prompting the government and the International Union for Conservation of Nature (IUCN) to list the bird as critically endangered (CR). However, subsequent census in 2016 showed that the number had increased to between 560 and 600 individuals, and its status was downlisted to vulnerable (VU). The wirebird resembles the Kittlitz’s plover, which a native species of Sub-Saharan Africa, but is slightly larger.
The plover was first documented in 1638, but was not observed by Charles Darwin when he visited Saint Helena for a period of 6 days in July 1836. The species spends early mornings and late afternoons in thickets and open grasslands feeding on caterpillars, beetles, and other small insects. The Saint Helena plover builds simple nests on the ground using soil, dry grass, stems, and rootlets. When threatened by predator, the plover distracts the predator away from the nest and often performs the "broken wing display," which involves simulating injury to attract the predator away from the nest. The species usually produces a clutch of two eggs, and both the female and male are involved during the incubation period, which lasts for about four weeks. Chicks leave the nest after about 36 hours and join their parents for feeding. The young birds become able to fly after six weeks, but stay close to the nest. After about six months, they move further from the nest to start their adult life.
Habitat and Range
The Saint Helena plover usually inhabits areas with short grass, low stem density, and broad-leaved weeds. The species also prefers flat regions with adequate rainfall, and can be found in parts of the island such as Deadwood Plain, Broad Bottom, and Prosperous Bay Plain. According to researchers, Saint Helena contained at least three native seabirds and six landbirds when humans first settled the island. Today, the wirebird is the only surviving native species on the island.
The population of Saint Helena plovers on the island fluctuates, but is significantly lower than it was during the 1970s. Loss of habitat and the introduction of invasive plant species are the likely causes of the decline. Between the 1950s and 1960s, there were approximately 1,000 individuals, but by 1990 the number had dropped to roughly 450 birds. In the early 2000s, the population had stabilized, at about 350 individuals, but by 2006 the number had declined further to only 200 adults. Conservation efforts resulted in an increase to 550 birds by 2016. The government and conservationists are now attempting to introduce the Saint Helena plover to neighboring uninhabited islands to help protect the species and boost its population.