Sitticus distinguendus
Key Details
| Taxonomic Groups: | Invertebrate > spider (Araneae) > Spider |
| Red List Status: | Critically Endangered (Not Relevant) [CR(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: | Attulus distinguendus |
| UKSI Recommended Authority: | (Simon, 1968) |
| 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: | CR, criteria: C2a(ii): no change since review (no Swanscombe survey/records since 2012). Restricted to Thames Gateway in GB. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Very small populations at two locations, both vulnerable to specific development threats and recreational activities. Not found in other apparently suitable brownfield and dune habitats. |
| 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): | 6. Recovery solutions trialled |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Combination - insufficient |
| Species Comments: | First described from GB in 2003 from brownfield sites in the Thames Gateway. A grey dune species on the near-continent but not yet found on dunes on the SE coast of England; possibly a relict of Thames terrace sand and gravel sites although accidental import cannot be ruled out. Thermophilic, on sparsely vegetated PFA and cement factory flue-ash substrates. |
Key Actions
Key Action 1
Proposed Action: Establish standardised monitoring of population extent, size and (initially) annual variability
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites: West Thurrock, Essex; Swanscombe, Kent
Comments: Important to relocate the Swanscombe population in relation to specific development threat
Key Action 2
Proposed Action: Investigate the potential of extending West Thurrock lagoon and Marshes SSSI to protect adjoining PFA (Pulverised Fuel Ash) brownfield sites that are relevant to the species.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Site protection
Duration: 3-5 years
Scale of Implementation: 1 site
High priority sites: West Thurrock
Comments: Would allow population expansion and movement to compensate for habitat loss from successional vegetation change, and protect from current recreational pressures e.g. trail biking.
Key Action 3
Proposed Action: Evaluate translocation to reduce stochastic and specific risks
Action targets: 7. Best approach adopted at appropriate scales
Action type: (Re-)introduction
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Other Thames Estuary PFS brownfields and, potentially, any more elevated quaternary sand and gravel river terraces sites
Comments:
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.