Countries of Occurrence:
Portugal - Madeira
Henriques, S. & Russell, N.
Facilitators / Compilers/s:
Meta barreti is endemic to Madeira Island, Portugal. This species was not found since 1987, despite extensive sampling, possibly due to the replacement by the endemic congener M. stridulans. Based on this threat, a continuing decline has probably affected the number of mature individuals, the extent of occurrence, area of occupancy and habitat extent and quality and the number of locations has been estimated as one. This species is therefore assessed as Critically Endangered (Possibly Extinct). More research is urgently needed to clarify whether this species is still extant.
Meta barreti is (or was) 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 in laurisilva forest, although none recently (Warburton 1892, Schmitz 1895, Kulczyński 1899, Bristowe 1925, Bacelar 1937, Schenkel 1938, Denis 1962, Wunderlich 1987, Wunderlich 1992). It was possible to perform species distribution modelling to predict its potential range with confidence limits (Cardoso et al. 2017). If the species is still present, the extent of occurrence (EOO) and area of occupancy (AOO) has a maximum estimate of ca 900 km².
No population size estimates exist, but the population is assumed to be declining based on the ongoing threats.
Meta barreti is restricted to the humid laurisilva forest on the northern slopes of Madeira Island. This species is an orb-web builder, possibly on the tree branches, feeding mainly on small insects. The congener M. stridulans is much larger (up to 11 mm), possibly giving it a competitive advantage.
The endemic congener M. stridulans is now commonly seen after description in 1987, about the same time as M. barreti was last recorded. It is possible there was replacement of one species by the other, both single island endemics, although this is for now only suspected. Based on this threat, the number of locations is assumed to be one.
No specific conservation measures are in place for the species, but all the species range is inside the Madeira Natural Park. If its apparent disappearance from the native range is confirmed some measures targeting species recovery should be implemented. The true distribution of the species and possible confusion with Meta stridulans should be clarified. Also research on the possible temporal replacement between these two species is needed.