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ST HELENA ENDEMIC INVERTEBRATES PROJECT

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St Helena is small, rugged 47 sq mile island in the Atlantic ocean, with a population of 4500, and it is a UK overseas territory. 

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  • Rarity: St Helena has over 420 endemic invertebrates, this a third of the UK's unique biodiversity on one tiny island. It includes the fantastical Spiky Yellow Woodlouse (pictured), which glows in the dark. 
     

  • Causes of decline: St Helena invertebrates are threatened by invasive plant and invertebrate species, and the destruction and degradation of their habitats. 

​ Golden Sail Spider Argyrodes mellissi (c) Roger Key 

​Threats to the endemic invertebrates of St Helena, include:

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  • Invasive species, including introduced plants and animals. 

  • Loss and fragmentation of native habitat, the habitats on island are very unique but they are vulnerable with increasing population pressures, these areas are getting smaller, further apart and more degraded.

  • Development on a small island where tourism is increasing, what looks like boring habitat can contain many endemics.

  • Climate change impacts.

The Species Recovery Trust is supporting projects on St Helena's endemic invertebrates by working directly with the invertebrate team in the St Helena National Trust, and we are currently the advising on the Cloud Forest Project, we provide specialist invertebrate advice for surveys, data analysis, report writing and increasing capacity for endemic invertebrate recovery outcomes. Species we are specifically supporting the recovery of  include the Spiky Yellow Woodlouse Pseudolaureola atlantica, the False Gumwood Leafhopper Sanctahelenia insularis, the St Helena Silver Grass Miner Elachista trifasciata and the Mole Spider Molearachne sanctaehelenae.

Our Work​

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  • The Species Recovery Trust is supporting surveys by St Helena National Trust in Cloud forest to record the endemic species, as well as DNA sequencing and taxonomic work.

  • Also, advising specific endemic species monitoring: the Golden Sail Spider Argyrodes mellissi (pictured, credit Roger Key), St Helena silver grass mining moth Elachista trifasciata and the Spiky Yellow Woodlouse Pseudolaureola atlantica.

  • Surveys and taxonomic work have discovered three new spider species to science from St Helena.

  • The Yellow Spiky Woodlouse and endemic species numbers have been found to be higher in restoration sites compared with some native forest sites and non-native vegetation. 

The Species Recovery Trust is also supporting invasive species control work on island. Controlling Common wasp Vespula vulgare and Big-headed ant Pheidole meagcephala. 

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Results of this work has shown massive declines in Big-headed ant as a result of control and with an indication of increases in endemic leafhoppers on those same sites.

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