Pearl-bordered Fritillary (Boloria euphrosyne)
Key Details
| Taxonomic Groups: | Invertebrate > insect - butterfly > Butterfly |
| Red List Status: | Vulnerable (Not Relevant) [VU(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: | Boloria euphrosyne |
| UKSI Recommended Authority: | (Linnaeus, 1758) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Fox & Dennis, 2021 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | GB Red List (Fox et al. 2022): VU. Statistically significant 72% decline in abundance since 1978 and a 24% short-term (10 year, 2010-2019) decline; 91% long term decline in distribution since 1982 and a 44% short-term decline (Fox et al. 2023) Rapid decline and retreat to parts of western England, now highly restricted in SE England. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | The Pearl-bordered Fritillary lives in close-knit colonies requiring short vegetation in sunny situations where there is an abundance of its foodplant, violets, mostly dog Violet (Viola riviniana). Once widespread in coppiced woodland and bracken habitats the species has disappeared from much of its former range, especially England and targeted conservation work is required. Requires targeted woodland management/bracken grassland management to create conditions for food plant, microclimate for larval development. |
| 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: | Species requires targeted, specific management. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 5. Remedial action identified |
| Recovery potential/expectation: | Low - Combination or other (detail in comments) |
| National Monitoring Resource: | Structured - sufficient |
| Species Comments: | Recovery potential is limited by a combination of climate change, extinction debt - particularly available suitable habitat and that which might be restorable. |
Key Actions
Key Action 1
Proposed Action: Autecological research on egg laying and larval development in light of climate change (increased grass growth during winter and nitrogen deposition); how can we adapt our habitat management practices to improve site suitability?
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: National
High priority sites:
Comments: Some work is being done with academic partners at Lancaster University but further work required and in other landscapes
Key Action 2
Proposed Action: Design and implement experiment to trial different bracken management techniques to create ideal/known conditions required by females for egg laying and subsequent larval development and survival.
Action targets: 6. Recovery solutions trialled
Action type: Scientific research
Duration: >10 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments:
Key Action 3
Proposed Action: Increase advice and support to landowners, advisors, land managers on appropriate management practices as results of scientific research become available.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Advice & Support
Duration: >10 years
Scale of Implementation: National
High priority sites:
Comments: There has been a lot of research work carried out on this species and we know what it does need but there are gaps in knowledge on the best way to manage some sites, research and trials will inform this and input into best practice advice and could help to inform management.
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.