St Helena Plover (Charadrius sanctaehelenae) is endemic to St Helena (to UK). This species is classified as Critically Endangered because its population was extremely small and declining owing to land-use change (particularly a decrease in grazing pressure) and predation by invasive predators. Since 2005, annual censuses have shown a stable or slightly increasing population, and the population has exceeded 250 mature individuals since at least 2007, with the most recent count in 2016 recording 559 mature individuals (Oppel in litt. 2015, Fisher 2016).
Until recently, there was considerable uncertainty over the possible impacts of the construction of a new airport on St Helena, and whether this (and associated developments) would cause a decline in the St Helena Plover population, potentially reducing the population to below 250 individuals (Prater et al, in litt. 2011). Airport construction was completed in 2015, and although the airport has not yet opened it appears that the C. sanctaehelenae population has not been adversely affected (Oppel in litt. 2015, Fisher 2016). Plans for the construction of associated developments (particularly hotels and golf courses) have not yet been realised (J. Hall, S. Oppel pers. comm. 2016).
The species has benefitted in recent years from on-going conservation efforts, including habitat restoration and control measures against introduced predators (J. Roberts in litt. 2010; Burns et al, 2013; Oppel et al., 2014). These efforts are continuing, now led by the St Helena National Trust (Fisher 2016).
As the population is now stable and there are more than 250 mature individuals meaning that it does not meet the numerical threshold criteria for Critically Endangered or Endangered status, it is proposed that the species be downlisted to Vulnerable under criterion D1 on the basis that the population is estimated to number fewer than 1,000 mature individuals, with no evidence of a continuing decline.
Additional information or comments on this proposed downlisting are welcome.
Burns, F., McCulloch, N., Székely, T. and Bolton, M. 2013. The impact of introduced predators on an island endemic, the St Helena Plover, Charadrius sanctaehelenae. Bird Conservation International 23: 125-135.
Fisher, I. 2016. St Helena plover: Wirebirds on the up? Available at http://www.rspb.org.uk/community/ourwork/b/biodiversity/archive/2016/07/05/st-helena-plover-wirebirds-on-the-up.aspx
Mcculloch, N.; Norris, K. 2001. Diagnosing the cause of population changes: localized habitat change and the decline of the endangered St Helena wirebird. Journal of Applied Ecology 38: 771-783.
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. J Appl Ecol, 51: 1246–1254.