IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackPholcus silvai Wunderlich, 1995

Pholcus silvai Wunderlich, 1995

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Family: Pholcidae
LC Least Concern
IUCN Red List Status:

Countries of Occurrence:
Portugal - Madeira

Archipelago(s):
Madeira

Reviewer/s:
Henriques, S. & Russell, N.

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

Pholcus silvai is endemic to Madeira Island, Portugal. This species has a restricted geographic range with a maximum estimate of extent of occurrence (EOO) and area of occupancy (AOO) of ca 900 km². However, Pholcus silvai is assessed as Least Concern (LC), since the preferred habitat of the species, humid laurisilva forest, is not experiencing any decline in area or quality and the population is therefore assumed to be stable. A monitoring of population trends should be conducted to confirm species status.

Geographic Range:

Pholcus silvai is known on the western side of Madeira Island, from both laurisilva forest and open areas above 450 m altitude. Multiple collection sites are recorded for the species (Wunderlich 1995). It was possible to perform species distribution modelling to predict its potential range with confidence limits (Cardoso et al. 2017). The extent of occurrence (EOO) and area of occupancy (AOO) have a maximum estimate of ca 900 km².

Regions:
Portugal - Madeira
Extent of Occurrence (EOO):
38-888,440 (km2)
Area of Occupancy (AOO):
20-888,440 (km2)
Elevation Lower Limit:
1800 (m)
Elevation Upper Limit:
450 (m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Madeira
Seasonality:
Resident

Population:

No population size estimates exist, but the preferred habitat of the species is not experiencing any decline in area and the invasive species present should not affect the spider populations, and therefore the population is assumed to be stable.

Habitat and Ecology

The species occurs in both laurisilva forest and open areas on the western side of the island. The ecology of this species is unknown but it is almost certainly a tangle-web builder feeding on small arthropods.

Major Threat(s):

There are no known threats to the species.

Conservation Actions

No specific conservation measures are in place for the species, but most of the species range is inside the Madeira Natural Park. Monitoring of population trends should be conducted to confirm this species' status.