Species

BackHahnia insulana Schenkel, 1938

Hahnia insulana Schenkel, 1938

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

Countries of Occurrence:
Portugal - Madeira

Archipelago(s):
Madeira

Assessor/s:
Luis Crespo
Mario Boieiro
Paulo A.V. Borges
Pedro Cardoso
Cardoso, P., Crespo, L.C., Silva, I., Borges, P. & Boieiro, M.

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

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

Hahnia insulana 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 700 km². However, Hahnia insulana 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:

Hahnia insulana is known throughout the laurisilva forest that occupies about 20% of the island of Madeira (Portugal), mainly on its steep and humid northern slopes. Multiple collection sites are recorded for the species, mostly recent (Schenkel 1938, Denis 1962, Crespo et al. 2014). 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) is estimated to be between 207-716 km² and the area of occupancy (AOO) to be between 188-708 km².

 

Regions:
Portugal - Madeira
Extent of Occurrence (EOO):
207-716,364 (km2)
Area of Occupancy (AOO):
188-708,364 (km2)
Elevation Lower Limit:
50 (m)
Elevation Upper Limit:
1700 (m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Madeira
Seasonality:
Resident

Population:

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

Habitat and Ecology

Hahnia insulana is restricted to the humid laurisilva forest on the northern slopes of Madeira Island. This species is a sheet-web builder among the leaf-litter and low vegetation feeding mainly on small insects.

Major Threat(s):

There are no known threats to this species.

Conservation Actions

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