Siphlonurus alternatus

Key Details

Taxonomic Groups: Invertebrate > insect - mayfly (Ephemeroptera) > Mayfly
Red List Status: Endangered (Not Relevant) [EN(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: Siphlonurus alternatus
UKSI Recommended Authority: (Say, 1824)
UKSI Recommended Qualifier: (none specified)
Red List Citation: Macadam, 2016
Notes on taxonomy/listing: (none)

Criteria

Question 1: Does species need conservation or recovery in England?
Response: Yes
Justification: This species is considered Endangered in Great Britain. In England there are confirmed recent records only from the River Dove in the Peak District. There is also a historical record from the River Severn near Kidderminster.
Question 2: Does recovery/ conservation depend on species-specific actions?
Response: Yes
Justification: This species would benefit from the establishment of additional populations to reduce the risk of extinction.
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: True but those are more general actions improving the ecosystem rather than being a species specific action

Species Assessment

Current step on the Species Recovery Curve (SRC): 3. National Monitoring Plan agreed and implemented
Recovery potential/expectation: Medium-high
National Monitoring Resource: Combination - insufficient
Species Comments: Conservation translocation recovery is high but currently untested.

Key Actions

Key Action 1

Proposed Action: Desk study to understand habitat requirements for the species

Action targets: 4. Autecology and pressures understood

Action type: Scientific research

Duration: 1 year

Scale of Implementation: Not applicable

High priority sites: N/A

Comments: Necessary step to inform future translocation

Key Action 2

Proposed Action: Investigate the feasibility of conservation translocations for this species.

Action targets: 5. Remedial action identified

Action type: Ex situ conservation

Duration: 3-5 years

Scale of Implementation: Not applicable

High priority sites: N/A

Comments:

Key Action 3

Proposed Action: Translocation of captive bred population to watercourses identified in Action 1

Action targets: 6. Recovery solutions trialled

Action type: (Re-)introduction

Duration: 3-5 years

Scale of Implementation: ≤ 5 sites

High priority sites: To be determined by Action 1

Comments:

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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.