Chalk Hill Blue (Polyommatus coridon)
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: | Polyommatus coridon |
| UKSI Recommended Authority: | (Poda, 1761) |
| 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. 5% decline in abundance since 1976 and a 1% short-term (10 year 2010-2019) increase; 82% long-term decline in distribution since 1978 and a 31% short-term decline (Fox et al. 2023) |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | A species of short to medium turf created by heavy/ medium grazing reasons for its local declines are unknown |
| 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: | Although there is some uncertainty here |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Low - Combination or other (detail in comments) |
| National Monitoring Resource: | Structured - sufficient |
| Species Comments: | A species that is responding differently across its range for reasons that are unclear at present |
Key Actions
Key Action 1
Proposed Action: Autecological research and detailed data analysis of responses on monitored sites to attempt to determine causes of decline.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 100 sites
High priority sites: downland
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.