IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackHystricella oxytropis (R.T. Lowe, 1852)

Hystricella oxytropis (R.T. Lowe, 1852)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Hygromiidae
NT Near Treatened
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:

Seddon (2008) suggested that the species should be considered as Vulnerable B2ab(iii) (version 3.1). This species has a total area of occupancy of 8 km2 with the main populations on two hills where the species is found in the eastern part of the island. The habitat has been subject to changing land-use practice, and as such the quality of the habitat has declined over the last thirty years. However, the decline in habitat has not significantly impacted the species in the last 10 years and the species is relatively abundant where it occurs (Cameron and Groh, pers. comm., 2010). Therefore the species is now viewed as Near Threatened, almost meeting criteria B.

Geographic Range:

This species is endemic to Porto Santo in the Madeiran islands. It is restricted to the east end of the island, with a total area of occupancy of 8 km2 with the main populations on slopes of two small hills (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:

There is no recent data on population trends, however can be locally abundant.

Habitat and Ecology

This species occurs under stones on grassland (Seddon 2008).

Major Threat(s):

The major threats lie in habitat loss through land-use change or grassland fires.

Conservation Actions

The species would benefit from grassland management and reduction of risk from grassland fires, as well as reducing impact of recreational activities in the habitats. Habitat monitoring is required to evaluate conservation status in the future, as if these activities are not impacting the species, then it could be downlisted.