Fancy-legged Fly (Campsicnemus magius)
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Long-legged fly |
| 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: | |
| UKSI Recommended Name: | Campsicnemus magius |
| UKSI Recommended Authority: | (Loew, 1845) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Drake, 2018 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Limited distribution; known sites are, Thames Estuary, North Kent/South Essex- Marshes between Cliffe and Isle of Sheppey with the greatest population. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | With few records in the previous 10 years of a recognisable species, this implies the need for at least ongoing surveying to establish whether populations at known sites persist. |
| 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: | With a reliance on saline/brackish water margins and mud, retention or provision of this within known and similar habitats may be of benefit. Build this into coastal flood defence schemes in the known areas as a definite action. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Life history factor/s |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Lee, P. et al., 2012 state that 80% of records are within SSSI's and debate the need for habitat that is not readily available outside of these areas. Surveying methods may impact recording efforts with a low flying fly that is often walking on or skimming the surface of water or mud. On one site most records are from pitfall traps as opposed to sweeping which could effect recording. |
Key Actions
Key Action 1
Proposed Action: Tailored surveys of potential habitat in known localities to determine the populations and species distribution, thus identifying areas where C. magius is missing as well as present.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: ≤ 50 sites
High priority sites: Thames Estuary, North Kent/South Essex- Marshes between Cliffe and Isle of Sheppey with the greatest population. Most recent records from Rushenden Marshes TQ903709, Witton Brook, Northwich SJ662747, Graveney Marshes TR060647
Comments: Baseline surveys of potential sites both to establish where present but also where missing, focus being on type of survey/collection methods specifically for targeting the species (i.e. pitfall trap and potential Malaise Traps). Perhaps explore created coastal retreat areas to assess their potential.
Key Action 2
Proposed Action: Based on outcomes of Action 1, provide advice and support to guide design of coastal flood defences to ensure habitat for this species is created/managed correctly
Action targets: 4. Autecology and pressures understood
Action type: Advice & support
Duration: >10 years
Scale of Implementation: ≤ 50 sites
High priority sites: Thames Estuary, North Kent/South Essex- Marshes between Cliffe and Isle of Sheppey with the greatest population. Most recent records from Rushenden Marshes TQ903709, Witton Brook, Northwich SJ662747, Graveney Marshes TR060647
Comments:
Key Action 3
Proposed Action: Creation of suitable habitats within known sites for feeding and mating opportunities, such as creation of muddy margins into shallow brackish/saline water to provide areas for feeding and mating displays.
Action targets: 4. Autecology and pressures understood
Action type: Habitat creation
Duration: Unknown
Scale of Implementation: ≤ 50 sites
High priority sites: Thames Estuary, North Kent/South Essex- Marshes between Cliffe and Isle of Sheppey with the greatest population. Most recent records from Rushenden Marshes TQ903709, Witton Brook, Northwich SJ662747, Graveney Marshes TR060647
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.