Countries of Occurrence:
Saint Helena - British Overseas Territory
Pryce, D. & White, L.
Facilitators / Compilers/s:
This is a very rare species confined to a single location in the ‘Eastern Arid Area’ of St Helena (as defined by Ashmole and Ashmole 2004) where an international airport is currently under construction. One of the two sites the species has been recorded from has been lost to the development; the earlier records, from ‘east of Prosperous Bay Plain’, has certainly been heavily impacted and may well also have been lost. This species has an area of occupancy (AOO) and extent of occurrence (EOO) both of 4 km². Therefore, it is assessed as Critically Endangered.
Endemic to the island of St Helena, in the South Atlantic Ocean, where it has been found at a single site in the ‘Eastern Arid Area’ of the island (as defined by Ashmole and Ashmole 2004).
The species was recorded from ‘east of Prosperous Bay Plain’ by the first expedition from the Royal Museum for Central Africa in Belgium in 1965-6 (Basilewsky 1972). As the precise location of this site is unknown there is a very significant probability that it has been impacted by the construction of the airport (taking place between 2012 and 2016) in this area; it may well have been lost entirely. During the Prosperous Bay Plain Survey in 2003 the species was found for a second time at the ‘Plateau Triangulation Point’ in southeastern Prosperous Bay Plain (Ashmole and Ashmole 2004); this site has been entirely removed to construct the terminal buildings for the airport. There is some remaining potentially similar habitat nearby but a large proportion of the known range of this species has certainly been lost to the development
This species is associated with a desert environment; while its precise ecology is unknown it may well be associated with Samphire (Suaeda fruticosa (L.) Forrssk) which is a common native plant in the area that supports other endemic species.
Construction of a new airport on St Helena has resulted in habitat destruction and potential future remaining habitat alteration. There has been an increase in the number of invasive non-native predators (e.g. Formicidae) and global warming is also a potential threat to habitat quality.
Any research and monitoring of this species would be of value. Of critical importance is the continued expansion and linking of habitat fragments as well as removal of invasive non-native species where this is possible.