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

Abstract 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.


Introduction
Portugal is a small country with a large coastal area that occupies the majority of the western coast of the Iberian Peninsula and is separated into two biogeographic regions, Mediterranean and Atlantic (European Environment Agency 2017). While there are still a few relatively pristine areas, the country is mostly covered by a permanently changing landscape. Portugal is currently investing heavily in tourism, one of the causes of unregulated urbanisation and coastal development, factors that lead to fragmentation and loss of coastal habitats (Freire et al. 2009). Wildfires are a significant threat over an increasingly long dry season, a factor that, although natural and long standing, has been exacerbated in recent years by both poor land management and climate change (IPCC 2014), posing a challenge to invertebrate conservation (Pryke and Samways 2011).
Finally, unsustainable land use management practices further threaten the stability of the country's ecosystems and long term co-existence between man and nature through activities that lead to soil erosion and introduction of exotic species (Nunes et al. 2011).
Despite ongoing disturbances, many of Portugal's natural characteristics still contribute towards a rich, unique fauna, spiders included (Arachnida: Araneae). The latest data show that 1488 spider species are known to occur in the Iberian Peninsula, of which 825 of them are present in mainland Portugal, 42 of those considered endemic to the country . While much of the Mediterranean and the Iberian Peninsula is considered a biodiversity hotspot, Portugal stands out for having a greater percentage of newly recorded endemic species (in the last decade) than Spain, despite representing only 15% of all new records for the Iberian Peninsula. The province of Faro in particular, Portugal's southernmost province and one of the country's most urbanised regions, at least along the coastal areas, is the province with the highest richness of new endemic species found during the last decade (16) as well as the province with the second highest richness (39) of Iberian endemics (after Illes Balears).
Portugal's duality as both highly speciose and highly under pressure along most of its territory makes it imperative to conduct studies that bridge both the gaps in our knowledge of spiders, as well as those between researchers and decision-makers. Both are being tentatively reduced by initiatives such as the Iberian Spider checklist and catalogue ) and now through the conservation status assessments of all national endemics. Of the 42 Portuguese endemic species, only one, the troglobiont Anapistula ataecina Cardoso & Scharff, 2009, has been assessed according to the IUCN Red List criteria . In addition to endemics, the only Iberian species protected by law in the mainland (Portuguese Republic 1999, Anex B-IV), Macrothele calpeiana, is also assessed, given its legal status.

Methods
All analyses were computed in R (version 3.5.1) using the package "red -IUCN redlisting tools" (Cardoso 2017), with the record data from published papers, grey literature and other databases, all compiled in the Iberian Spider Catalogue . This package performs a number of spatial analyses, based on either observed occurences or estimated ranges, some of which are needed for correctly following the IUCN Red List criteria. Its functions include calculating the Extent of Occurrence (EOO), Area of Occupancy (AOO), mapping species ranges, species distribution modelling using climate and land cover, calculating the Red List Index for groups of species, amongst others. The calculation of confidence limits is possible for all measures (see further details below). Maps and data on geographical ranges, elevation and others can be exported in a variety of formats used for the assessments themselves, as well as visual presentation and safekeeping.
Species with less than five georeferrenced records were considered to be insufficiently known and classified as Data Deficient (DD). When it was possible to reliably due so, i.e. for species with sufficient distribution data, EOO and AOO were calculated in one of two ways: 1. For troglobiont species, we assumed that we knew well enough the full range of the species, based on the fact that Portuguese cave systems are relatively well explored. We then classified these values as observed and used our occurrence records to: • Calculate EOO by building a minimum convex polygon that encompassed all observations. • Calculate AOO by summing the area of all 2 x 2 km cells known to be occupied.
2. For non-troglobiont species with at least five records, species distribution modelling (SDM) was performed.
This was done using the environmental data present in Worldclim 2.0 (Fick and Hijmans 2017) and the function map.sdm in the R package red to build ensemble models (Breiner et al. 2018, Lomba et al. 2010. One hundred models were run per species using both coordinates and the associated spatial error. This ensemble modelling was made with the Maxent method (Phillips et al. 2006). No variable subsets were used. Normally, only a subset of two variables from the total set would be used for better output predictions in rarer species as it mitigates overfitting (Breiner et al. 2018, Lomba et al. 2010), but it was found during execution that this resulted in possible overestimations of the range. Following the precautionary principle, we opted to use the full set of variables, even if risking overfitting for some species. Ensembles were weighted-summed using the Area Under the Curve (AUC) values to weight each of the 100 runs as: weight = max(0, (AUC -0.5)) These probabilistic models were then processed with the map.habitat function, which further restricted them to patches, including observation points, thus often reducing the range and consequently the EOO and AOO values. We present for each assessment the EOO and AOO for both the consensus maps and their lower confidence limits (in reverse order in the assessments themselves), calculated respectively as the areas found suitable in at least 50% and 97.5% of the 100 models created per species (after weighting of individual models). All final maps and values were checked and validated by our own expert opinion. All data, presented in the Results section, use the lower confidence limits as per the precautionary principle and includes the previously assessed Anapistula ataecina.
run run 2 Habitat System: Terrestrial

Habitat specialist: Unknown
Habitat (narrative): This spider is known from four sites, only two of these possessing habitat information. The species seems to be associated with Quercus spp. and Olea sp.

Dependency of single sp?: No
Ecology and traits (narrative): A nocturnal ground-dwelling species that produces no web and eats a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Observed
Basis (narrative): Few collection sites are recorded for this species (four records), mostly recent and all of them in caves in the Algarve (Ribera 1993, Reboleira et al. 2011. Due to its nature as a troglobiont species and the fact that Portuguese caves are relatively well sampled, the known record points should accurately reflect reality.

Min Elevation/Depth (m): 38
Justification for trend: This spider currently faces threats of habitat loss due to urbanisation, land use change on the surface altering the microclimate beneath and stone quarries.

Basis for decline:
-(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat  Ferrández, 1990 Species information

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Multiple collection sites are recorded for this species (seven records), mostly recent and in a variety of habitats. It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 335
Range description: This spider has been recorded in southern Portugal along the coast (Ferrández 1990, Cardoso et al. 2008a, Lissner 2017b. The species distribution modelling predicts that the species could be widespread along this area.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Multiple collection sites are recorded for this species (seven records) from both published sources (Wunderlich 2017) and our own data, all recent and in coastal dune vegetation. It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 121
Range description: This spider is known exclusively from dune sites scattered across Portugal's southern coasts (Wunderlich 2017). The species distribution modelling predicts that the species' true range probably does not stray far from known occurrence records.

EOO (km2): 1503 -1798
Trend: Decline (inferred) Justification for trend: The sand dunes, from where this species is exclusively found, are delicate habitats threatened by habitat loss due to urbanisation and possible increase in number of extreme weather events due to climate change.

Number of locations: Unknown
Justification for number of locations: The data available is not enough to estimate the number of locations.

Number of individuals: Unknown
Trend: Decline (inferred) Justification for trend: The sand dunes, from where this species is exclusively found, are delicate habitats threatened by habitat loss due to urbanisation and possible increase in number of extreme weather events due to climate change.

Basis for decline:
-(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
There is only one record for the species (Lissner 2017a) in a maquis in Sobral da Adiça, Beja. Its true range is therefore unknown and not possible to model with confidence.

Max Elevation/Depth (m): 350
Range description: This spider is known from only one site in a maquis in Sobral da Adica, Beja, southern Portugal (Lissner 2017a).

Dependency of single sp?: No
Ecology and traits (narrative): If similar to congeners, a nocturnal active hunter that is found at the understorey level, eating a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Trend: Unknown
Justification for trend: The data available (two records) are not enough to estimate the number of subpopulations.

System: Terrestrial
Habitat specialist: Unknown

Habitat (narrative):
This spider is known from only two sites. The habitat of both places is unspecified.

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance Habitats: -18. Unknown

Dependency of single sp?: No
Ecology and traits (narrative): If similar to congeners, this spider is a nocturnal active hunter that lives at the understorey level.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Conservation action type: In Place
Conservation actions: -1.1. Land/water protection -Site/area protection -1.2. Land/water protection -Resource & habitat protection Justification for conservation actions: It is unknown exactly where this spider was found in São Brás de Alportel. Future records might reveal its true range to be partially covered by the Natura 2000 network (PTCON0049 and PTCON0057) as it is within 5 km of known occurence points.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): There are only two records for the species (Crespo and Mendes 2010). The true range is therefore unknown and not possible to model with confidence.

Max Elevation/Depth (m): 230
Range description: This spider is known from only two sites in south Portugal, one in Corval and the other one in Montoito, Évora (Crespo and Mendes 2010). They are also both in cork oak woodlands with scattered bushes.

Dependency of single sp?: No
Ecology and traits (narrative): If similar to congeners, these spiders are active predators that consume a variety of invertebrates at ground level.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Largely unknown, as there is only one record for the species (Wunderlich 2011). The true range is therefore unknown and not possible to model with confidence.

Max Elevation/Depth (m): 10
Range description: This spider is known from only one site in a sandy area near the beach east of Fuseta, Algarve, southern Portugal (Wunderlich 2011).

Dependency of single sp?: No
Ecology and traits (narrative): If similar to conspecifics, this spider is an active ground hunter that does not build a web and consumes a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Land/water protection -Resource & habitat protection
Justification for conservation actions: It is unknown exactly where this spider was collected but it is fair to assume that its true range might be completely or at least partially covered by the Natura 2000 network (PTZPE0017 and PTCON0013). It might also be totally or partially covered by the Ria Formosa Natural Park.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Dependency of single sp?: No
Ecology and traits (narrative): This tube-and sheet-web builder creates small burrows on vertical walls, tree trunks or even at ground level, often adopting existing burrows. It is predominantly nocturnal and is reported as performing both sit-and-wait hunting, as well as active hunting.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Conservation action type: In Place
Conservation actions:

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Multiple collection sites are recorded for this species (30 records), mostly recent and in caves, albeit rarely it can also be found in pinewood forests (Fage 1931, Machado 1942, Cardoso 2004, Bosmans et al. 2010. It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 894
Range description: This spider is a well-established presence in cave systems throughout north and central Portugal, with a single record existing for Monchique in the Algarve (Fage 1931, Machado 1942, Cardoso 2004, Bosmans et al. 2010). The species distribution modelling confirms its widespread nature, as well as predicting that the species could also occur in Spain's north-westernmost region of Galicia.

Number of locations: Unknown
Justification for number of locations: The number of threats needed to completely cover the species range is unknown but, in any case, larger than 10.

Trend: Decline (inferred)
Justification for trend: Many of the underground habitats that this spider inhabits have been damaged or destroyed by pollution from human and agricultural activity (such as septic tanks and other forms of waste), infrastructure building (such as wind farms), quarries and overall disturbance from human presence, including the destruction and removal of geological structures that form this species' habitat.

Number of individuals: Unknown
Trend: Decline (inferred) Justification for trend: Many of the underground habitats that this spider inhabits have been damaged or destroyed by pollution from human and agricultural activity (such as septic tanks and other forms of waste), infrastructure building (such as wind farms), quarries and overall disturbance from human presence, including the destruction and removal of geological structures that form this species' habitat.

Basis for decline:
-(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat

Number of subpopulations: Unknown
Trend: Decline (inferred) Justification for trend: Many of the underground habitats that this spider inhabits have been damaged or destroyed by pollution from human and agricultural activity (such as septic tanks and other forms of waste), infrastructure building (such as wind farms), quarries and overall disturbance from human presence, including the destruction and removal of geological structures that form this species' habitat.

System: Terrestrial
Habitat specialist: No

Habitat (narrative):
This spider is a troglophile species recorded mostly in caves (18). A fair amount of records possess no habitat information (9) and, less commonly, they possess information for pinewood forests (2) and a mine (1).

Trend in extent, area or quality?: Decline (inferred)
Justification for trend: Many of the underground habitats that this spider inhabits have been damaged or destroyed by pollution from human and agricultural activity (such as septic tanks and other forms of waste), infrastructure building (such as wind farms), quarries and overall disturbance from human presence, including the destruction and removal of geological structures that form this species' habitat.

Conservation action type: In Place
Conservation actions: -1.1. Land/water protection -Site/area protection -1.2. Land/water protection -Resource & habitat protection

Justification for conservation actions:
This spider is a widespread species. Some of the caves it inhabits are currently covered by protected areas namely the Serra de Aire e Candeeiros Natural Park, the Peneda-Gerês National Park and the Montejunto Regional Protected Landscape. It is therefore reasonable to be expected that it is covered at large by a variety of sites designated by the Natura 2000 network.

Other
Use type: International

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Multiple collection sites are recorded for this species (5 records). It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 754
Range description: This spider has been recorded only in northern Portugal, mostly recent but without much habitat information although at least one record was from a mixed oak forest (Hormiga andScharff 2005, Cardoso et al. 2008b). The species distribution modelling predicts that its distribution could be scarce, restricted to small patches in the north-westernmost tip of Portugal.

Trend: Stable
Justification for trend: There are no currently known threats to the species.

System: Terrestrial
Habitat specialist: Unknown Habitat (narrative): Despite being recorded several times, only one of this spider's records includes habitat information for a mixed oak woodland containing Quercus robur and Quercus pyrenaica (Cardoso et al. 2008b).

Trend in extent, area or quality?: Unknown
Justification for trend: There are no currently known threats to the species.
Habitat importance: Major Importance

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
Largely unknown as there is only one record for the species (Bosmans et al. 2010) in Douro Internacional Natural Park, Bragança.

Max Elevation/Depth (m): 690
Range description: This spider is known from only one site in a Quercus pyrenaica (Willd.) forest (Bosmans et al. 2010). The species' true range is therefore unknown and not possible to model with confidence.

Ecology and traits (narrative):
A ground-dwelling species that is active during both night and day, actively hunting for a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Ecology and traits (narrative):
A ground-dwelling species that produces no web and hunts actively, consuming a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Land/water protection -Resource & habitat protection
Justification for conservation actions: This spider was collected in three sites, one of which was in the centre of the Paul de Arzila Natural Park, which in turn is located inside the Natura 2000 network (PTZPE0005, PTCON0005).

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Largely unknown, as there are only two records for the species (Cardoso et al. 2008b, Denis 1965 in northern Portugal, in the provinces of Braga and Porto.

Range description
This spider is known from only two sites in Braga and Porto, north-western Portugal (Cardoso et al. 2008b, Denis 1965. Its true range is therefore unknown and not possible to model with confidence.

Dependency of single sp?: No
Ecology and traits (narrative): An active hunter that builds no web and eats a variety of small invertebrates.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Largely unknown, as there is only one record for the species (Lissner 2017a), in a maquis near Azeitão, Setúbal.

Max Elevation/Depth (m): 195
Range description: This spider is known from only one site in a maquis in a limestone region (Lissner 2017a). Its true range is therefore unknown and not possible to model with confidence.

Trend: Stable
Justification for trend: Despite the present threats to some of its subpopulations, the wide geographical and habitat range of this spider makes it plausible that the trend is mostly stable.

Causes reversible?: Yes
Population Information (Narrative): No estimates of population size exist.

Trend: Stable
Justification for trend: Despite the present threats to some of its subpopulations, the wide geographical and habitat range of this spider makes it plausible that the trend is mostly stable.

Habitat specialist: No
Habitat (narrative): Highly diverse. This spider has been found in marshes, grasslands, shrublands (Cytisus and Genista), forests (Quercus spp.) and plantations (Eucalyptus sp. and Pinus spp.), most often in clay or compacted soil.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance

Land/water protection -Resource & habitat protection
Justification for conservation actions: This spider has been recorded in several protected areas across its distribution, from its south-westernmost tip at the Arrábida Natural Park to its north-easternmost tip at the Douro International Natural Park. Due to its widespread nature, it is no doubt present in numerous areas protected by the Natura 2000 network.

Other
Use type: International

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
There is only one old published record for the species (Frade and Bacelar 1931) attributed to the small village of Fagilde, Viseu and two other records for typical burrows with moults found in the vicinity of the type locality.

Max Elevation/Depth (m): 400
Range description: This spider is known from only one site (Frade and Bacelar 1931) and the area immediately adjacent to the small village of Fagilde, Central Portugal. The true range is therefore unknown and not possible to model with confidence.

Trend: Decline (inferred)
Justification for trend: Few records and a lack of population data are not enough to estimate the species range or extinction risk trend. However, habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Trend: Decline (inferred)
Justification for trend: Few records and a lack of population data are not enough to estimate the species range or extinction risk trend. However, habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Number of locations: Unknown
Justification for number of locations: Until further information on this spider's distribution is recorded, the number of locations is unknown.

Trend: Decline (inferred)
Justification for trend: Habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Number of individuals: Unknown
Trend: Decline (inferred) Justification for trend: Few records and a lack of populational data are not enough to estimate the species extinction risk. However, habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Basis for decline:
-(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat

Number of subpopulations: Unknown
Trend: Decline (inferred) Justification for trend: The data available are not enough to estimate the number of subpopulations. However, habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Habitat specialist: No
Habitat (narrative): This spider was originally found in an unspecified habitat, but horizontal burrows (a distinct burrow not present in other Iberian species) were found in leaf litter on the verge of local forests.

Trend in extent, area or quality?: Decline (inferred)
Justification for trend: Habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species habitat is likely declining in area and quality.

Habitat importance: Major Importance
Habitats: - Justification for threats: Habitat loss in the area due to agriculture, urban infrastructure development and wildfires indicates the species is likely declining.

Land/water protection -Resource & habitat protection
Justification for conservation actions: This spider has not been recorded in areas inside or adjacent to protected areas. More records are needed in order to confirm or disprove this for the species' true range.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Multiple collection sites are recorded for this species (12 records), mostly recent (Bacelar 1937, Main 1949, Decae et al. 2007. It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 532
Range description: This spider has been recorded almost exclusively in the Algarve, being recorded only once in the nearby region of southern Alentejo (Bacelar 1937, Main 1949, Decae et al. 2007). The species distribution modelling suggests that it might also be present in south-western Spain, between the border with Portugal and the Guadalquivir's delta -a similar prediction to that present in Decae et al. 2007.

EOO (km2): 17013 -20967
Trend: Decline (inferred) Justification for trend: Several subpopulations have been eradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

AOO (km2): 5028 -7520
Trend: Decline (inferred) Justification for trend: Several subpopulations have been eradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

Number of locations: Unknown
Justification for number of locations: The number of threats needed to completely cover the species range is unknown but, in any case, larger than 10.

Number of individuals: Unknown
Trend: Decline (inferred) Justification for trend: Several subpopulations have been erradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

Basis for decline:
-(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat

Causes reversible?: No
Population Information (Narrative): No estimates of population size exist.

Number of subpopulations: Unknown
Trend: Decline (inferred) Justification for trend: Several subpopulations have been eradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

Habitat specialist: No
Habitat (narrative): Habitat information was recorded only twice in bushlands (dominated by Cystus sp.). Expert knowledge suggests that it is found in coastal areas (open areas, plateaus, small cliffs and roadsides), as well as mountainous regions of oak forest ( Quercus suber) in the Algarve.

Trend in extent, area or quality?: Decline (inferred)
Justification for trend: Several subpopulations have been eradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

Habitat importance: Major Importance
Habitats: -3.8. Shrubland -Mediterranean-type Shrubby Vegetation -6. Rocky areas (e.g. inland cliffs, mountain peaks) -13.1. Marine Coastal/Supratidal -Sea Cliffs and Rocky Offshore Islands Ecology and traits (narrative): A ground-dwelling, nocturnal spider that builds a tube web and eats a variety of small invertebrates (mainly beetles).

Threats
Threat type: Ongoing Justification for threats: Several subpopulations have been eradicated by urban development and many more are often disturbed or depleted by trampling, mostly in touristic areas, to access the coast line. Severe wildfires have recently devastated known occurrence regions, affecting a considerable number of subpopulations. A few subpopulations have been eradicated in the past due to habitat destruction caused by eucalyptus plantations, but this threat appears to have been halted in recent years.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Observed
Basis (narrative): Multiple collection sites are recorded for this species (22 records), mostly recent and all of them in caves (Fage 1931, Ribera 1988, Ribera and López-Pancorbo 2011, Reboleira 2012. Due to its nature as a troglobiont species and the fact that Portuguese caves are relatively well sampled, the known record points should accurately reflect reality. This spider belongs to a recently described genus that seems to be constituted entirely by troglobiont species. Its eyes are absent and it captures small invertebrates with a space web positioned on cave walls and often inside crevices.

Threats
Threat type: Ongoing

Region for assessment:
-Global

Dependency of single sp?: No
Ecology and traits (narrative): Diurnal active hunters that reside in both ground and vegetation levels. They eat a variety of small invertebrates and construct no web.

Threats
Threat type: Past Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Land/water protection -Resource & habitat protection
Justification for conservation actions: It is unknown exactly where this spider was collected but it is fair to assume that its true range might be partially or completely covered by the Natura 2000 network (PTZPE0047 and PTCON0018). It might also be totally or partially covered by the Sapal de Castro Marim e Vila Real de Santo António Natural Reserve.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
There is only one record for the species (Wunderlich 2011). The true range is therefore unknown and not possible to model with confidence.

Dependency of single sp?: No
Ecology and traits (narrative): If similar to congeners, a ground tube-web builder that is active during both night and day.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Land/water protection -Resource & habitat protection
Justification for conservation actions: It is unknown exactly where this spider was collected, but it is fair to assume that its true range might be completely or at least partially covered by the Natura 2000 network (PTZPE0017 and PTCON0013). It might also be totally or partially covered by the Ria Formosa Natural Park.

Use type: International
Ecosystem service type: Very important

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
There is only one record for the species (Wunderlich 2011) near a beach in Aljezur, Faro. The true range is therefore unknown and not possible to model with confidence.

Max Elevation/Depth (m): 20
Range description: This spider is known from only one site located next to a beach in Aljezur, Algarve, Southern Portugal (Wunderlich 2011).

Habitat specialist: Unknown
Habitat (narrative): This spider is known from only one site located next to a beach. The habitat of the site itself, where the specimen was found, is not specified, but it is assumed based on its location to be sand dunes.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
There is only one record for the species (Lecigne 2017). The true range is therefore unknown and not possible to model with confidence.

Ecology and traits (narrative):
The genus Amphiledorus has been recently described so not much information is available. However, a single species, Amphiledorus histrionicus (Simon, 1884) was once part of genus Selamia, members of which are described as hiding during the day in sand-covered silken retreats that serve at the same time as both hiding corners and capturing devices, with prey being ambushed from underneath the retreat (Jocqué and Bosmans 2001).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): There are only three collection sites recorded for this species (3 records), mostly recent and always in sand dunes (Bosmans 1994, Pekár et al. 2011. The true range is therefore unknown and not possible to model with confidence.

Max Elevation/Depth (m): 376
Range description: This spider is known from only three sites in southern Portugal, always in sand dunes (Bosmans 1994, Pekár et al. 2011).

Causes ceased?: Unknown
Justification for trend: The sand dunes, in which this species has been found, are delicate habitats that are threatened by habitat loss and possible increase in number of extreme weather events due to climate change.

System: Terrestrial
Habitat specialist: Yes Habitat (narrative): This spider has been found so far exclusively on sand dunes. All records are associated with sand dune habitats except for the record from the Algarve which, while possessing no habitat information, is located on a coastal area.
Trend in extent, area or quality?: Decline (inferred) Justification for trend: The sand dunes, in which this species has been found, are delicate habitats that are threatened by habitat loss and possible increase in number of extreme weather events due to climate change.
Habitat importance: Major Importance Ecology and traits (narrative): An ant-eating species that produces no web and uses specialised predator behaviour and mimicry in order to capture its prey.

Threats
Threat type: Ongoing

Dependency of single sp?: Unknown
Ecology and traits (narrative): An ant-eating species that produces no web and uses specialised predator behaviour and mimicry in order to capture its prey.

Threats
Threat type: Past Threats: -12. Other options -Other threat Justification for threats: The existence of threats is unknown for this species.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Multiple collection sites (5 records) are recorded for this species, mostly recent, but with scarce habitat information (Pekár et al. 2003). It was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Max Elevation/Depth (m): 353
Range description: This spider has been recorded in central and southern Portugal. The species distribution modelling predicts that this species could be widespread throughout the region and could be present in Spain along its southern border with Portugal.
From the 43 species evaluated, only 18 had enough data to allow their EOO and AOO to be quantified. Of these, we modelled the distribution of 14 epigean species, eight of which were found to be widespread (both EOO > 20 000 km and AOO > 2000 km ). The remaining six fulfilled at least one of the criteria for threatened species. Four species are troglobiont, whose distribution was assumed to be well known and therefore assessed using the known occurrence points: Anapistula ataecina, Domitius lusitanicus, Harpactea stalitoides, Teloleptoneta synthetica. As expected from species with such life history, all of them fulfil the EOO and AOO thresholds for threatened species. The remaining 25 Portuguese endemics (59.5%) had no reliable information on their range (Fig. 2). Even though the last decade has seen a large increase in the knowledge of Iberian spiders , the available information is still far from satisfactory and it is not possible to assess the majority of species for their risk of extinction. Population trends equally suffer greatly from lack of information. From the 43 species assessed, only nine are estimated to be in decline, 11 stable, with the majority of species having no information on trends (23 species, Fig. 3). Although there is a larger number of species with a restricted EOO amongst those declining than those with stable population numbers, this difference is not very noticeable. It is, however, observable that stable species are far more likely to have larger EOO (>20000 km2). A difference between both trend groups is much more observable when comparing AOO values, with species occupying less than 500 km2 being more commonly declining (Fig. 4).  Portuguese endemics occupy a variety of habitats. Forest areas (15 species), sand dunes (12 species), shrublands (10) and caves (6) host the majority of species (Fig. 5). All four most represented habitats are inhabited by a number of species exclusive to them. From all four, sand dunes have the largest count of exclusive species (9) and forests have the largest count of non-exclusive species (10). Range (EOO and AOO) categories of all species, arranged according to their population trends. Species classified as "In decline" in red, species classified as "Stable" in green, species classified as "Unknown" in grey.

Figure 5.
Habitat categories amongst all 42 species assessed. Species exclusive to each habitat in red.
Forests vary considerably in their composition of dominant trees, according to the biogeographic region in question and are frequently both natural and semi-natural systems.
Besides the threat of man-made wildfires, increasingly important during this era of accelerated climate change, endemic Portuguese forests and shrublands face an additional, ongoing threat to their extension: the mass production of Eucalyptus globosum (Labill). Often poorly managed plantations may not only be exacerbating the occurrence of wildfires (Fernandes et al. 2011), but also seem to have direct consequences in invertebrate diversity (Cammell et al. 1996, Zahn et al. 2009, Corcuera et al. 2015) that should be addressed.
Species occurring on sand dunes are significantly represented, with a majority being exclusive to this habitat. However, given most of these species have no reliable information on their range, future research may prove this to be at least partly biased, either due to recent work targeting this habitat (Carvalho et al. 2011) or many foreign scholars having collected preferentially in this habitat type while on vacation. Regardless, the importance of protecting sand dune habitats in Portugal is indisputable and these areas must continue to be considered important conservation areas in both national environmental legislation as well as local legislation, such as municipal land use plans (PDMs). As Portugal expands to accommodate its growing tourism industry, efforts must be made to direct this growth inwards instead of continuously stressing a coastal region with an outstanding natural value (Deharveng et al. 2000, Cuttelod et al. 2008).
When considering Anapistula ataecina , troglobiont species represent 9.5% of endemic species. Cave systems are often home to species with very restricted distributions and these habitats are more sensitive to perturbation than most other habitat types. Current limestone quarries, in areas like Serra da Arrábida, pose a serious threat to several species. A change in the opening of a cave system can modify its temperature, airflow, humidity and completely wipe out a subpopulation in a way that is irreversible without structural work being performed post-occupation (Cardoso and Scharff 2009). One should note, though, that often conservation priorities are in conflict and habitat recovery might imperil some species. Gruta do Zambujal is such an example: structural changes to the cave's entrance have led to increased airflow and temperature changes inside, reducing endemic spider fauna while simultaneously allowing the colonisation by protected bat species.
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 (Fig. 6), although other factors are also important and represented across the data.
A considerable proportion of the currently known Portuguese endemic richness can be found in national protected areas, with special focus on the natural park system. Out of 234 records used, 112 were located inside protected areas (47.8%). The Serras de Aire e Candeeiros Natural Park has the largest number of records within it (31), followed by Douro Internacional Natural Park (16), Vale do Guadiana Natural Park (12), Sudoeste Alentejano e Costa Vicentina Natural Park (11) and Arrábida Natural Park (10). Of all species considered here, 29 (69.0%) possess at least one record in an area belonging to the National Protected Area Network (RNAP). Although this might seem encouraging and somehow indicating that protected areas are well located, most of these numbers might be due to the fact that these specific protected areas in Portugal were relatively well sampled during the recent decades (Cardoso 2004. Presence in the Natura 2000 network is also common. The (PTCON0015) Serras de Aire e Candeeiros site has the most records (29), followed by (PTZPE0047) Vale do Guadiana (12), the (PTCON0012/PTZPE0015) Costa Sudoeste and (PTCON0010) Arrábida / Espichel (10) sites, (PTCON0061/PTZPE0004) Ria de Aveiro (8) and the (PTCON0049) Barrocal and (PTCON0048) Serra de Montejunto (7) sites. Out of 234 records, 169 are located inside areas of the Natura 2000 network (72.2%). Of all species considered in this study, 31 (73.8%) possess at least one record in an area belonging to the Natura 2000 network.
Finally, regarding conservation measures needed to protect endemic spider species, site/ area protection and/or resource & habitat protection were invariably found to be most important. This is especially critical since no spider endemic to mainland Portugal is protected by law, national or international and hence their protection has never been considered in conservation plans and only when they coincide with protected areas or other protected species, is it possible to somehow safeguard them. As mentioned previously, the only spider protected in the country is not endemic, Macrothele calpeiana and should be assessed as Least Concern, given its wide range and high adaptability to different habitat types. Threat categories amongst all species.