Assessment Rationale:

Seddon (2008) noted that this species is on the European Union and Habitats Directive Species Annex II and IV which means that a SAC should be designated for this species. Latest evaluation suggests it meets the criteria for Critically Endangered B1ab(iii) (version 3.1). All recent records are only from Garajau, a single area on the south side of Madeira, where habitat area and quality has been reduced through a building development above the cliffs for residents and tourists. The habitats are under pressure due to continued development, although main habitats are on the sea-cliff beneath where possible threats include invasive plants, fire and tipping. The previous assessment was Endangered (IUCN 1996), but the knowledge of range was more limited and recent survey shows that it is restricted to Garajau, so the revised assessment is based on new data.

Geographic Range:

This species is endemic to Madeira, where it has always been rare. Seddon (2008) notes that is restricted to the south coast of Madeira (Cabo Garajau to Cabo Girao) and similar range was reported by Wollaston (1878), Paiva (1866) and Nobre (1931). Paiva's records are from west of Funchal, whereas Wollaston's records all come from the Garajau area. Recent records (NMW database, field records 1984, 1995) confirm the species is still living on sea-cliffs by Cabo Garajau (Seddon 2008).

Population:

Estimates of population size by field recording suggest that the species is not common at the site.

Habitat and Ecology

Discula tabellata lives in crevices of bare rock faces, on dry stone walls and at the base of grasses and herbs on cliff top boulders.

Major Threat(s):

All recent records are only from Garajau, a single area on the south side of Madeira, where habitat area and quality has been reduced through a building development above the cliffs for residents and tourists. The habitats are under pressure due to continued development, although main habitats are on the sea-cliff beneath where possible threats include invasive plants, fire and tipping.

Conservation Actions

This species is listed on the European Union Habitats Directive Species Annex II and IV, which means that a SAC should be designated for this species. Further conservation actions required are a habitat monitoring programme for the species (as a proxy for population trends).