Current view: Text account
Site description (2015 baseline):
Site location and context
This site mostly consists of two vegetation types, semi-desert habitat extending inwards from the coast, which leads into pastures and non-indigenous woodlands dominated by Pennisetum, Cynodon and Digitaria, with Acacia and Pinus up to 500 m altitude (Prater, 2012). The site comprises dry pasture areas supporting the most important breeding site for Charadrius sanctaehelenae at Deadwood Plain, and includes other important breeding sites at Bottoms Woods and Woody Ridge (Prater, 2012). The semi-desert habitats also support important C. sanctaehelenae breeding sites around Prosperous Bay Plain (where the new airport is situated), Prosperous Bay North, Upper Prosperous Bay Plain and Horse Point Plain (Prater, 2012). Further important breeding sites of C. sanctaehelenae include Banks Ridge, Fishers Valley, Longwood Erosion Zone, Longwood Farm, Stone Top Ridge and Weather Station Ridge.
See table for key species. There are 11 breeding landbird species, these being Alectoris chukar, Phasianus colchicus, Gallinula chloropus, Charadrius sanctahelenae, Columba livia, Geopelia striata, Acridotheres tristis, Foudia madagascariensis, Lonchura oryzivora, Estrilda astrild and Serinus falviventris (Prater, 2012). Nine of these species have been introduced, with the exceptions being G. chloropus and the last remaining endemic species of St Helena C. sanctahelenae. This site supports c.62% of the adult population of C. sanctaehelenae with an average of 221 adults between 1998 and 2014 (George & Beard, 2014).
Non-bird biodiversity: Prosperous Bay Plain is an important invertebrate area supporting a large range of endemic spiders and beetles (with over 400 endemic species being present on St Helena (Churchyard et al., unpub.)). Of the endemic invertebrates two are particularly well known, Labidura herculeana (CR) and Aplothorax burchelli (CR), both known from Horse Point Plain, and were last seen in the mid-1960s and are likely to be extinct. The areas of higher elevation support much of the remaining endemic vegetation (of which there are a total of 44 species for St Helena) including Commidendrum robustum, Dicksonia arborescens, Pladaroxylon leucadendron, Lachanodes arborea and Melanodendrum integrifolium, Trochetiopsis ebenus and T. throxylon (Prater, 2012).
Pressure/threats to key biodiversity
Introduced predators pose the most immediate threat to the C. sanctaehelenae population, primarily feral cat and rat predation (George, 2015). A feral cat control program was initiated by RSPB in July 2011 and implemented in partnership with the Saint Helena National Trust through to March 2014 (George, 2015). The feral cat control program was sustained by the SHNT from September 2014 to mid-December 2014 and the aim is for this to be continuous. Rats are locally controlled in areas where the rodent population is particularly high around important C. sanctaehelenae areas. Introduced A. tristis also occasionally predate on eggs and chicks however currently this is not a major threat. Development has also had an impact through removing suitable C. sanctaehelenae habitat, such as the new airport development on Prosperous Bay Plain due to open in 2015 which has taken a large area of C.sanctaehelenae habitat. Mitigation for this has included clearing sites of Ulex europaeus, Opuntia elatior, Optuntia ficus-indica and other shrubs to provide new suitable habitat for the C. sanctaehelenae population. A Hotel development has been proposed on Woodlands and Broad Bottom, which is another Important Wirebird Site (George, 2015).
Many thanks to Kevin George from the Saint Helena National Trust and Annalea Beard from the Environmental Management Division for preparing the nomination and for providing data. Also to Eddie Duff and Dennis Leo from the Saint Helena National Trust and to Leeann Henry and Elizabeth Clingham for their help with data collection.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Fishers Valley Flat (St Helena (to UK)). Downloaded from
https://datazone.birdlife.org/site/factsheet/fishers-valley-flat-iba-st-helena-(to-uk) on 27/12/2024.
