4f4c4942-4343-5764-6473-313135383934 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-10-07T14:24:51.251Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) A survey of the spider Agroeca dentigera on Dyfi National Nature Reserve, with a particular focus on Ynylas Dunes (2013-2014) A survey of the spider Agroeca dentigera on Dyfi National Nature Reserve, with a particular focus on Ynylas Dunes (2013-2014) Arolwg o'r corryn Agroeca dentigera ar Warchodfa Natur Genedlaethol Dyfi, gan ganolbwyntio'n arbennig ar Dwyni Ynyslas (2013-2014). 2015-03-31 NRW_DS115894 http://naturalresources.wales/ The sand dune system at Ynyslas, part of Dyfi National Nature Reserve (NNR), supports the only known UK population of the IUCN Vulnerable liocranid spider Agroeca dentigera. Surveys undertaken in 2013 and 2014 sought to determine the species' current status and distribution, following its last confirmed record in 2002, and to improve understanding of its habitat preferences and ecological requirements through targeted surveys of the dune system and other potentially suitable habitats within the NNR. The sand dune system at Ynyslas, part of Dyfi National Nature Reserve (NNR), supports the only known UK population of the IUCN Vulnerable liocranid spider Agroeca dentigera. Surveys undertaken in 2013 and 2014 sought to determine the species' current status and distribution, following its last confirmed record in 2002, and to improve understanding of its habitat preferences and ecological requirements through targeted surveys of the dune system and other potentially suitable habitats within the NNR. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en National Museums Liverpool National Museums Liverpool, 127 Dale Street, Liverpool, L2 2JH, England steve.judd@liverpoolmuseums.org.uk Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme araneae sand dune ecology RDB spider Ynyslas Dyfi NNR invertebrate surveys spiders NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW, 2015. There are no use restrictions on this data. Recipients may re-use, reproduce, disseminate this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and NRW's copyright, and do not use it in a misleading context. It is the recipient's responsibility to ensure the data is fit for the intended purpose, that dissemination or publishing does not result in duplication, and that it is fairly interpreted. Advice on interpretation should be sought where required. To avoid re-using old data, users should periodically obtain the latest version from the original source. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence English biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 SIR CEREDIGION - CEREDIGION GWYNEDD - GWYNEDD -4.09042728 -3.88502338 52.46437737 52.57828018 2013-10-01 2014-10-10 A survey of the spider agroeca dentigera on Dyfi NNR with a particular focus on Ynyslas Dunes in 2013 and 2014 Database Unknown Species records on Welsh Invertebrate Database Documents https://naturalresources.wales/media/684924/report-054-survey-of-spider-agroeca-dentigera-on-dyfi-nnr.pdf Report as pdf format Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false Sites were surveyed in October 2013, April 2014 and October 2014 using a combination of hand-searching and mechanical sampling techniques. A total of 136 person-hours was devoted to searching potentially suitable habitats across Dyfi NNR. A modified leaf blower was used on one survey occasion to assist sampling. A single adult female Agroeca dentigera was recorded on 3 October 2014 within an area of dense marram grass in the dune system. Surveys of other potentially suitable habitats did not record the species. Although its habitat preferences remain poorly understood, the available evidence suggests that A. dentigera is associated with dense marram-dominated dune habitat at Dyfi NNR. In addition to A. dentigera, 94 spider species were recorded, including Philodromus fallax and Ceratinopsis romana. Eleven spider species and a further sixteen non-spider invertebrate species are thought to represent new records for Dyfi NNR. An additional 47 non-spider invertebrate species were also recorded during the surveys. The considerable survey effort required to locate a single specimen suggests that A. dentigera occurs at very low densities, making the development of effective monitoring protocols challenging. Some voucher specimens have been retained and are held in the collections of Liverpool Museum. The data were provided to NRW for inclusion within Recorder 6, with data transfer underway at the time of reporting. Sites were surveyed in October 2013, April 2014 and October 2014 using a combination of hand-searching and mechanical sampling techniques. A total of 136 person-hours was devoted to searching potentially suitable habitats across Dyfi NNR. A modified leaf blower was used on one survey occasion to assist sampling. A single adult female Agroeca dentigera was recorded on 3 October 2014 within an area of dense marram grass in the dune system. Surveys of other potentially suitable habitats did not record the species. Although its habitat preferences remain poorly understood, the available evidence suggests that A. dentigera is associated with dense marram-dominated dune habitat at Dyfi NNR. In addition to A. dentigera, 94 spider species were recorded, including Philodromus fallax and Ceratinopsis romana. Eleven spider species and a further sixteen non-spider invertebrate species are thought to represent new records for Dyfi NNR. An additional 47 non-spider invertebrate species were also recorded during the surveys. The considerable survey effort required to locate a single specimen suggests that A. dentigera occurs at very low densities, making the development of effective monitoring protocols challenging. Some voucher specimens have been retained and are held in the collections of Liverpool Museum. The data were provided to NRW for inclusion within Recorder 6, with data transfer underway at the time of reporting.