Also known as the Saint Helena Plover (charadrius sanctaehelenae) , it is locally called the “Wirebird” due to its long, thin, wiry legs. The upperparts are dark brown, with pale buff fringes, while the underparts are white with variable amounts of buff on the flanks. The head is distinctively marked with a black band running across the forecrown and around the eyes, with a white stripe immediately above that encircles the head.
First recorded in 1638 (but, curiously, not observed by Charles Darwin during his visit in July 1836) it is featured on St. Helena’s coat of arms and is held in great affection by island residents. 5 pence coins issued prior to 1998 have the wirebird on the reverse.
The Wirebird is officially classed as ‘critically endangered’, with only 322 individuals reported in the most recent survey. The reasons for their decline are not yet fully understood and research is ongoing but it has recently been established that changes in grazing patterns may be a significant factor. Predation of eggs and chicks by rats and feral cats is also likely.
Wirebirds feed on ground-living insects, especially beetles and caterpillars, which they catch using a ‘run and grab’ technique. Foraging typically accounts for around 60% of daytime activity and is most intensive in the early morning and late afternoon. Wirebirds will occasionally continue to feed after dark, at least on bright moonlit nights.
They nest on the ground. The nest is a simple scrape in the soil with a thin lining of dry grass stems and rootlets. This lining is used to cover the eggs when an incubating adult leaves the nest in response to disturbance, thus making the nest extremely difficult to find. They defend their nests by luring predators away, initially by running at speed as soon as the threat is detected, and then by doing a ‘broken wing display’ – the bird acts as if it is injured to gain the attention of the predator and draw it away from the nest. The clutch is, almost invariably, of two eggs and both sexes share incubation. The incubation period is approximately four weeks. Chicks normally leave the nest within 36 hours of hatching and are led to feeding areas by the parents. Young Wirebirds fledge when 5-6 weeks old, but may stay within their birth territory for some time afterwards. Wirebirds in their first year tend to range much farther than adults.
The areas most favoured by Wirebirds can be categorised as having grass swards less than 10cm tall (typically dominated by Kikuyu Grass pennisetum clandestinum), of relatively low stem density and mixed with broad-leaved weeds and patches of bare earth. Good Wirebird sites generally have shallow gradients and annual rainfall within the range 300-500mm. They can be found around Prosperous Bay Plain, Deadwood Plain and Broad Bottom.
It is known that St. Helena supported at least six endemic land bird species and three endemic seabirds in the past. It is likely that at least seven of these were present at the time of first human colonisation of the island. Of these, only the Wirebird remains, and thus it is the only endemic vertebrate remaining on the island.
A video in which talks about the Wirebird: