Current GBIF occurrence data demonstrates both promise and limitations for potential red listing of spiders.

Conservation assessments of hyperdiverse groups of organisms are often challenging and limited by the availability of occurrence data needed to calculate assessment metrics such as extent of occurrence (EOO). Spiders represent one such diverse group and have historically been assessed using primary literature with retrospective georeferencing. Here we demonstrate the differences in estimations of EOO and hypothetical IUCN Red List classifications for two extensive spider datasets comprising 479 species in total. The EOO were estimated and compared using literature-based assessments, Global Biodiversity Information Facility (GBIF)-based assessments and combined data assessments. We found that although few changes to hypothetical IUCN Red List classifications occurred with the addition of GBIF data, some species (3.3%) which could previously not be classified could now be assessed with the addition of GBIF data. In addition, the hypothetical classification changed for others (1.5%). On the other hand, GBIF data alone did not provide enough data for 88.7% of species. These results demonstrate the potential of GBIF data to serve as an additional source of information for conservation assessments, complementing literature data, but not particularly useful on its own as it stands right now for spiders.

An update to the Iberian spider checklist (Araneae).

We updated a previous database that compiled all the information available in 2010 for the species distribution of spiders (Araneae) in the Iberian Peninsula, Balearic Islands (Illes Balears) included. By the end of 2018 a total of 30834 records were compiled. These belong to 1493 species, 282 of those endemic to the peninsula, across 56 families and 402 genera. This represents an increase of approximately 14% in the number of species in the last nine years. From all families found in the Iberian Peninsula, Araneidae represent the highest number of records (3315), Linyphiidae the highest species richness (302) and Dysderidae the highest endemic richness (58). When considering only the 2010 decade, Linyphiidae lead in both number of records (1417) and species (49), but Gnaphosidae have the highest newly described endemic richness (18). When looking at the full data per province, the largest number of records are located in Illes Balears (1864), followed by Barcelona (1287). When it comes to species, Huesca (474) and Barcelona (470) are the richest provinces. However, it is Illes Balears that possesses the largest known endemic richness (43), followed by Beja and Faro (39). Regarding the last decade, Illes Balears received the largest sampling effort with 901 records, followed by Girona (806). Ciudad Real had the highest increase in known richness with 191 new species to the province, followed by León and Lleida (188). The most new endemic species were found in Faro (16), followed by Almería and Cádiz (13). This checklist is accompanied by an online catalogue where all its information is fully listed.

Species conservation profiles of spiders (Araneae) endemic to mainland Portugal.

BACKGROUND: The Iberian Peninsula is a diverse region that contains several different bioclimatic areas within one confined space, leading to high biodiversity. Portugal distinguishes itself in this regard by having a high count of spider species (829) and a remarkable number of endemic spider species (42) for its size (approximately 88,890 km2). However, only one non-endemic species (Macrothele calpeiana) is currently protected by the Natura 2000 network and no endemic spider species (aside from Anapistula ataecina) has been assessed according to the IUCN Red List criteria. The objective of this paper is to assess all non-assessed endemic species (41) as well as M. calpeiana. NEW INFORMATION: The 43 assessed species belong to 15 families, the richest being Zodariidae, Dysderidae, Linyphiidae and Gnaphosidae. In general and despite the lack of information on more than half the species, general patterns and trends could be found.Only 18 species (including M. calpeiana and A. ataecina) had enough data to allow their EOO (extent of occurrence) and AOO (area of occurrence) to be quantified. Of these, we modelled the distribution of 14 epigean species, eight of which were found to be widespread. The remaining six fulfilled at least one of the criteria for threatened species. Four species are troglobiont, all of which meet the EOO and AOO thresholds for threatened species. The remaining 25 Portuguese endemics had no reliable information on their range. Only nine species out of the 43 are estimated to be in decline and 11 are stable, with the majority of species having no information on trends (23 species).Forest areas, sand dunes, shrublands and caves host the majority of species. As such, the threats to Portuguese endemics reflect the diversity of habitats they occupy. Urbanisation and climate change seem to be the most important threats to these species, although other factors are also important and represented across the data.A considerable proportion of the currently known Portuguese endemic species can be found in national protected areas, with higher prominence to the Serras de Aire e Candeeiros, Douro Internacional, Vale do Guadiana, Sudoeste Alentejano e Costa Vicentina and Arrábida Natural Parks. These correspond mostly to areas that have been particularly well sampled during the last two decades.