MAIISG

Assessment Rationale:

This species is restricted to Porto Santo, and hence has a restricted range. However the present population abundance and habitat, suggests that it is not highly threatened as it is fairly widespread with three subpopulations on different islets. The mainland populations are most susceptible, given the multiple threats causing habitat degradation and impact of non-native species. However, the species is currently viewed as Least Concern (LC), based on current habitat and threats, but could move to a more threatened category should habitat degradation accelerate.

The confirmation of three subpopulations on different islets reduces the threat of extinction, and so this new data lead to the downlisting from the previous assessment of Near Threatened to Least Concern.

Geographic Range:

This species is endemic to the Madeiran islands. It is is only known from Porto Santo, where it is widespread, mainly on the lower slopes and coastal grasslands, especially on the eastern end of the island, and it is also present on the two offshore islets of Ilheu de Baixo and Ilheu de Cal (Seddon 2008).

Population:

This species is thought to be stable. It is often frequent at suitable site (Cameron, pers.comm., 2010).

Habitat and Ecology

This species is found on the underside of stones on scree slopes and at the base of crags.

Major Threat(s):

The population on the mainland are most susceptible from habitat loss from tourist development or habitat degradation due to invasive species (plants), fire or tipping or loss of populations due to introduced rodents.

Conservation Actions

The presence of large populations on two off-shore islets and populations on Pico Branco means that part of the range is protected. Hence no further conservation actions are needed.