MAIISG

Assessment Rationale:

TThis species is endemic to the Madeiran Islands (Portugal), where it is restricted to Porto Santo and the adjacent islets of Ilhéu de Baixo and Ilhéu de Cima. The main threat to the species is habitat degradation and loss due to development for tourism purposes and changes in agricultural practice. However these threats only affect the species population at Porto Santo. The recent programmes of both eradication of rabbits and removal of introduced plants have lead to major improvements in the habitats on Ilhéu de Baixo and Ilhéu de Cima. The island and its land snail fauna are recognized by the regional government as requiring conservation actions and currently work is ongoing to produce management plans. It is currently listed as Near Threatened (NT), given the restricted number of locations and the present threats to a part of the population (locations at Porto Santo).

Geographic Range:

This species is endemic to the Madeiran Islands (Portugal), where it is restricted to Porto Santo and the adjacent islets of Ilhéu de Baixo and Ilhéu de Cima (Walden 1983, Cameron et al. 1996, Abreu and Teixeira 2008, Seddon 2008). Wollaston (1878) commented that this “form”, as he recorded it, was common on Baixo and Cima. Based on a small area of occupancy (AOO) of 16 km2 , this species has been found at four localities within coastal habitats on the main island of Porto Santo, and further localities have been confirmed on the islets of Baixo and Cima.

Population:

There are no population abundance data for this species in Porto Santo, although there are regular records over the last 25 years (Seddon 2012 pers. comm.). The subpopulations on the islets of Baixo and Cima are regarded as large.

Habitat and Ecology

The species is typically found in contact with bare earth underneath stones and logs.

Major Threat(s):

The main threat is habitat degradation and loss. Some of these habitats are potentially threatened by development for tourism purposes, which affects especially coastal bays. Meanwhile, other sites are found within fields where there have been significant changes in agricultural practice, including intensification of production, use of fertilizers and pesticides, as well as increased frequency of fires, all of which disrupt the habitats. There has been a reduction in the habitat quality in the islets of Baixo and Cima due to introduced animal species (rabbits) and vegetation. However, recent programmes have managed to eradicate or significantly reduce the populations of these species, which has lead to major improvements on the habitats. Hence, the locations at both islets are regarded as not threatened at present.

Conservation Actions

A management plan has been produced for the Natura 2000 SAC "Ilhéus do Porto Santo", which covers the species population on Cima and Baixo Islets (Governo Regional da Madeira 2009a). The recent programmes of both eradication of rabbits and removal of introduced plants have lead to major improvements in the habitats on Ilhéu de Baixo and Ilhéu de Cima. The islands and their land snail fauna are recognized by the regional government as requiring conservation actions and currently work is ongoing to produce management plans.