Cliff Mason Bee (Osmia xanthomelana)
Key Details
| Taxonomic Groups: | Invertebrate > insect - hymenopteran > Bee |
| Red List Status: | (Not Relevant) [(not listed)(nr)] |
| D5 Status: | |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Osmia xanthomelana |
| UKSI Recommended Authority: | (Kirby, 1802) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | (not listed) |
| Notes on taxonomy/listing: | Listed as Endangered (RDB1) in Shirt (1987) and Falk (1991).Possibly extinct in England (extant in north Wales). |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | The species may now be extinct in England. It has probably been in decline since the 19th Century and was formerly thinly scattered in localities across southern England and even north to Cumbria. There have been no records from the last known location, Red Cliff on the Isle of Wight, for over 25 years. However, it might still occur on the Isle, a long-known locality, either at Red Cliff or on other clifftop grasslands. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Fails Q1 because accounted for elsewhere: the only English representative of this section H. mirandum is now regarded as extinct (see H. mirandum account). |
| 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: | Possibly. The cause of its long, nationwide decline is uncertain, but in modern times the vulnerability of nesting sites may be a key factor. Active landslip areas that maintain bare ground for nesting are needed. Grassland rich in legumes, especially Bird's-foot trefoil will also be needed. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Combination or other (detail in comments) |
| National Monitoring Resource: | Opportunistic - sufficient |
| Species Comments: | There is a need to refind this species anywhere in England, before more detailed recovery plans can be formulated. Inaccessible cliff top nesting sites may allow some populations to linger on, undetected. |
Key Actions
Key Action 1
Proposed Action: Survey all former sites to ascertain presence/absence and also suitable habitat elsewhere on the Isle of Wight and the adjacent mainland.
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 3-5 years
Scale of Implementation: ≤ 10 sites
High priority sites: Isle of Wight, especially Red Cliff, Sandown and Luccombe Cliffs; suitable habitat flanking The Solent.
Comments: Extinction in England needs to be confirmed or disproved.
Key Action 2
Proposed Action: Work with conservation land managers to promote species-specific habitat requirements within relevant Coastal Zone Management Plans.
Action targets: 6. Recovery solutions trialled
Action type: Landscape/catchment/marine management
Duration: >10 years
Scale of Implementation: National
High priority sites: Isle of Wight
Comments: This bee lives in a dynamic environment of unstable cliffs and requires consideration at a landscape level to ensure potential nesting sites are widely distributed.
Key Action 3
Proposed Action: If rediscovered at any English site, instigate annual monitoring and habitat assessment, leading to sympathetic habitat management.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Other (specify in comments)
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites:
Comments: If an extant population is discovered, it may well be small and very vulnerable. The population should be monitored and an assessment of the extent of suitable forage and nesting habitat made, with appropriate actions consequent to this. Most likely on the Isle of Wight but the environs of former localities elsewhere in England should be surveyed.
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.