IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackCanariphantes relictus Crespo & Bosmans, 2014

Canariphantes relictus Crespo & Bosmans, 2014

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Family: Linyphiidae
CR Critically Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores

Archipelago(s):
Azores

Reviewer/s:
Russell, N.

Contributor/s:
Lamelas-López, L. & Mendonca, E.

Facilitators / Compilers/s:


Assessment Rationale:

Canariphantes relictus is a single-island endemic species restricted to S. Maria island (Azores, Portugal) (Crespo et al. 2014). It is a very rare species, with a restricted Extent of Occurrence (EOO) (8 km2 ) and Area of Occupancy (AOO) (8 km²). The species only occurs in a small patch of exotic modified forest, dominated by Cryptomeria japonica, Pittosporum undulatum and Acacia spp. There is a continuing decline in the EOO, AOO, extent and quality of habitat as well as the number of mature individuals as a result of the invasions of non-native plants; and in the past, the species has probably strongly declined due to changes in habitat size. The species is assessed as Critically Endangered (CR). We suggest as future measures of conservation: (1) a long-term monitoring plan of the species; (2) careful management of the areas of exotic plantations around Pico Alto native forest patch, and (3) control of invasive plant species.

Geographic Range:

Canariphantes relictus is a single-island endemic species restricted to S. Maria island (Azores, Portugal) (Crespo et al. 2014), known from Natural Forest Reserve of Pico Alto (Natural Park of S. Maria). The Extent of Occurrence (EOO) is 8 km2 and the maximum estimated Area of Occupancy (AOO) is 8 km2 . 

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

Population:

The species is very rare and only occurs in a marginal small patch of exotic forest (dominated by Cryptomeria japonica and the invasive species Acacia spp. and Pittosporum undulatum) included in a Natural forest Reserve of S. Maria island (Crespo et al. 2014). A continuing decline in the number of mature individuals is inferred from monitoring schemes (Borges et al. 2016) and from the ongoing habitat degradation due to invasions of alien plants (namely Pittosporum undulatum and Hedychium gardnerianum) and Cryptomeria japonica management. Current Population Trend: Decreasing.

Habitat and Ecology

The species only occurs in a marginal small patch of exotic forest (dominated by Cryptomeria japonica and the invasive species Acacia spp. and Pittosporum undulatum) included in a Natural forest Reserve of S. Maria island (Crespo et al. 2014). It has an altitudinal range between 400 and 560 m. Adults were collected from June to August (Crespo et al. 2014). This species builds a typical sheet-web at ground level. Systems: Terrestrial.

Major Threat(s):

In the past, the species has probably strongly declined due to changes in habitat size and quality (Triantis et al. 2010). Currently, the rapid advance and expansion of invasive plants species is the major threat, particularly Hedychium gardnerianum but also Pittosporum undulatum, which are changing the structure of the forest and the cover of bryophytes and ferns in the soil which will impact the species' habitat quality. Since the known specimens were captured in a marginal area dominated by Cryptomeria japonica, Pittosporum undulatum and Acacia spp., the type of management of Cryptomeria japonica plantations around the main core area of native forest of Pico Alto (S. Maria) will be critical for the long-term maintenance of this rare species. Since there are plans for future removal of old plantations of Cryptomeria japonica, the current habitat of the species is under threat. Based on Ferreira et al. (2016) the habitat will further decline as a consequence of climate change (increasing number of droughts and habitat shifting and alteration).

Conservation Actions

The species is not protected by regional law, however, its habitat is in a regionally protected area (Natural Park of S. Maria). Despite this, the Pico Alto Forest Reserve has an intermediate level of protection (currently classified in category III) and we strongly recommend a future change to category I, a wilderness area managed mainly for wilderness protection, so that its natural features can be properly safeguarded. Degraded areas, degraded due to invasive plant species should be restored and a strategy needs to be developed to address the current threat by invasive species and the future threat of climate change. There should also be careful management of the areas of Cryptomeria japonica exotic plantations around the Pico Alto native forest patch. Formal education and awareness is needed to allow future investments in restored habitats invaded by invasive plants; while further research is needed into its ecology and life history in order to find additional specimens in other areas of forest on S. Maria and obtain adequate information on population size, distribution and trends. An area-based management plan is also necessary for the most disturbed sites, including invertebrate monitoring to contribute to a potential species recovery plan. Monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al. 2011).