Wiehlea calcarifera
Key Details
| Taxonomic Groups: | Invertebrate > spider (Araneae) > Spider |
| Red List Status: | Endangered (Not Relevant) [EN(nr)] |
| D5 Status: | Included in the baseline Red List Index for England (Wilkins, Wilson & Brown, 2022) |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Wiehlea calcarifera |
| UKSI Recommended Authority: | (Simon, 1884) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Harvey et al., 2017 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | EN, criteria: B2ab(ii,iv). Restricted to S England. Recorded at only 1 (new) site since 2017 review but still apparently lost from 12 others. Under-recording may be an issue with this winter active, probably troglophilic, species. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Extreme rarity relative to apparent habitat availability |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | No |
| Justification: | This species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Appears to live in coarse soils on open heathland, probably surviving under gorse, and deep under among pine/oak litter on sandy soils, as well as in short chalk grassland. Probably troglophilic. |
Key Actions
Key Action 1
Proposed Action: Targeted survey of all recorded, nearby and apparently suitable sites, using standardised methodology to assess current status (and establish baseline for national monitoring programme)
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments: Seek advice of soil ecologists on sampling for all likely troglophilic species
Key Action 2
Proposed Action: Autecological research to establish microhabitat requirements and inform management
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: Redmoor SSSI, Cornwall
Comments: Only current possibility of achieving this is at Redmoor, Cornwall. Progressive gorse clearance work there offers possibility of monitoring/experimental trails of broken ground and subsequent successional stages, and of testing survey methodologies (e.g. subterranean pitfall trapping).
Key Action 3
Proposed Action: Ensure site managers are aware of species past/recent presence and vulnerability on their sites. Update them with Action 1 and 2 results to provide any resulting guidance on locations/management and inform commissioning of invertebrate survey work (methods likely to detect/damage species, need for retention and examination of spider by-catch when not a survey target)
Action targets: 5. Remedial action identified
Action type: Advice & support
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: Redmoor SSSI/NR, Cornwall
Comments: Management advice may become a more important action once habitat preferences are better understood (Action 2). Assemble mailing list and update site managers at species-appropriate intervals; most easily delivered by BAS/SRS.
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.