Slow-worm (Anguis fragilis)

Key Details

Taxonomic Groups: Vertebrate > reptile > Reptile
Red List Status: Least Concern (Not Relevant) [LC(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: Anguis fragilis
UKSI Recommended Authority: Linnaeus, 1758
UKSI Recommended Qualifier: (none specified)
Red List Citation: Foster et al., 2021
Notes on taxonomy/listing: (none)

Criteria

Question 1: Does species need conservation or recovery in England?
Response: Yes
Justification: In some places, slow-worm populations have become fragmented leading to smaller, isolated populations. The species requires recovery action as it has reduced conservation status. It is likely that slow worms have lost a lot of suitable habitat over the last 50 years but it remains uncertain as to the conservation status of slow worms on the remaining suitable habitat
Question 2: Does recovery/ conservation depend on species-specific actions?
Response: Yes
Justification: To a great extent, recovery will be aided by generic actions, but some species-specific action is also needed to ensure the particular needs of the species are considered, and so that action is properly advised on, co-ordinated and evaluated. Survey work is important to determine the status of this species.
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: Yes
Justification: This species would likely benefit substantially from efforts to increase habitat diversity. The scale of benefits would depend on precisely what work was done, and the main risk would be in increasing the level of dense scrub or tree cover. Linking habitats with linear structures such as hedgerows would benefit this species.

Species Assessment

Current step on the Species Recovery Curve (SRC): 5. Remedial action identified
Recovery potential/expectation: Medium-high
National Monitoring Resource: Combination - insufficient
Species Comments: Further development of and investment in national monitoring is required. The National Reptile Survey (NRS, part of the National Amphibian and Reptile Monitoring Programme) started recently and will generate useful data with further uptake. Considerable data is generated by the ARGs and this needs to be more accessible to establish detailed distribution maps.

Key Actions

Key Action 1

Proposed Action: The species has very low dispersal ability, so habitat creation and management are required to create and maintain corridors linking small populations for demographic and genetic viability. Explore solutions for the management and creation of habitat, to relieve key threats including fragmentation, excessive shading (created by tree planting and/or lack of management), and conflicts in management objectives for co-occurring species.

Action targets: 6. Recovery solutions trialled

Action type: Scientific research

Duration: 6-10 years

Scale of Implementation: ≤ 10 sites

High priority sites: National, possibly focused in areas of greater losses, such as areas of high development,

Comments: This research would involve experimental habitat management, trialling solutions for a number of threats to slow worms. Issues to address include excess shading, and site management conflicts. The action will also consider the likely impacts of a changing climate and the implications for management. This action could potentially be brigaded with the similar action for grass snake, adder and common lizard, as there is an overlap in some issues. Some shading could be beneficial with the impacts of climate change. This is the case for all widespread reptiles. Re-wetting habitus such a heathland/moorland may also help.

Key Action 2

Proposed Action: Identify, and consider the potential to designate, sites as SSSIs with widespread reptiles as an interest feature (reptile assemblage).

Action targets: 7. Best approach adopted at appropriate scales

Action type: Site protection

Duration: >10 years

Scale of Implementation: National

High priority sites:

Comments: Identification of ≤ 20 SSSIs. Identification of around 10 sites per county or equivalent area for non-statutory designation (most likely Local Wildlife Sites). This is proposed as a 'brigaded action' for the four widespread reptile species, where many of the sites would be designated for several of these species. For widespread reptiles (excluding adders) designation on SSSIs can only be notified as part of a reptile assemblage feature. The revised (Bernhard et al., 2022) SSSI guidance for amphibians and reptiles provides better guidance for boundary setting, which will facilitate designation of larger SSSIs than previously. Aside from its inherent benefits now, this action would help future-proof the protected site series for reptiles in the face of a changing climate.

Key Action 3

Proposed Action: Different activities and habitat types pose specific opportunities and threats for the species, and practical guidance will help to maximise conservation benefit and to minimise negative impacts. Develop guidance and training courses for specific themes of significance to the conservation of this species, including: management of agricultural land ; management of especially favourable habitats such as linear features like road verges, and improving connectivity with the wider countryside; forestry; re-wilding; protected sites; development impacts; disturbance impacts; wildfire prevention and response.

Action targets: 7. Best approach adopted at appropriate scales

Action type: Education/awareness raising

Duration: 3-5 years

Scale of Implementation: National

High priority sites:

Comments: Brigaded action across four widespread reptile species (slow-worm, common lizard, grass snake and adder). This action would include simple guidance leaflets, detailed guidance (including a web-based resource), road shows, videos, and training courses. To be developed over a period of three years. Over a longer period of time these resources would be updated to take account of new research and practice (including from work proposed in Action 1), and also as pressures and potential conservation measures change. Brigaded action as many of the issues will be similar across the four widespread reptile species; however, species-specific guidance will be required and incorporated as relevant.

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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.