IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackHystricella leacockiana (Wollaston, 1878)

Hystricella leacockiana (Wollaston, 1878)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Hygromiidae
VU Vulnerable
IUCN Red List Status:

Countries of Occurrence:
Portugal - Madeira

Archipelago(s):
Madeira

Assessor/s:
Seddon, M.B.

Reviewer/s:
Cameron, R., Groh, K., Cuttelod, A. & Neubert, E.

Contributor/s:
Abreu, C. & Teixeira, D.

Facilitators / Compilers/s:


Assessment Rationale:

This species has a total area of occupancy of 8 km2 with the main population on a small hillslope area where the species is found in the western part of the island, with an additional small subpopulations near the eastern coast where the habitat has been subject to changing land-use practice, and as such the quality of the habitat at the site has declined over the last thirty years, although the main area falls within a designated protected area. However, the current threats are mainly to the coastal sites, and so the other subpopulations are thought to be less threatened (Cameron and Groh, pers. comm., 2010). Therefore this species is assessed as Vulnerable D2. Should the threats impact the other subpopulations, then the species would directly qualify as Endangered B2ab(iii).

Geographic Range:

This species is endemic to Porto Santo, Madeiran  islands. It is restricted to the west end of the island, around Pico d'Ana Ferreira, with one record from the east end of the island. It is rarely found as a Quaternary fossil, possibly reflecting range restricted distribution through time (Seddon 2008).

Regions:
Portugal - Madeira
Extent of Occurrence (EOO):
(km2)
Area of Occupancy (AOO):
8 (km2)
Elevation Lower Limit:
(m)
Elevation Upper Limit:
(m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Madeira
Seasonality:
Resident

Population:

This species when present, can be abundant, however it is very localised.

Habitat and Ecology

This species is found under stones on grassland, and in scree, leaf-litter at base of small rock crags or in quarries.

Major Threat(s):

The species is found in the western part of the island, with an additional small subpopulations near the coast where the habitat has been subject to changing land-use practice due to hotel and villa construction, and use of sand deposits for small quarries, and as such the quality of the habitat has declined over the last thirty years. The areas behind are used for recreation as well as grazing land and although the main area falls within a designated protected area, the major threats would be change of land-use (construction) or invasive plants.

Conservation Actions

This species is listed on the EU Habitats and Species Directive Annex II and the Council of Europe Bern Convention Appendix 2. This species is present in a small grassland on western Porto Santo, so recommended conservation actions include management of the grassland areas for maintenance of this species and to ensure no loss of further habitat and possible selection of part of the range as a protected area. Research actions include population monitoring and habitat monitoring, especially for the populations near to tourist facilities.