Serotine (Eptesicus serotinus)
Key Details
| Taxonomic Groups: | Vertebrate > terrestrial mammal > Bat |
| 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: | Eptesicus serotinus |
| UKSI Recommended Authority: | (Schreber, 1774) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Mathews & Harrower, 2020 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | GB and England status is vulnerable. The National Bat Monitoring Programme (NBMP) trend is stable but should be treated with caution due to a lack of data. This species appears to have undergone declines in number in the east of England. It is a species that roosts within built structures and most often roof spaces. It is therefore highly vulnerable to disturbance and impacts on roosting needs. The reliance on unimproved grassland with its great scarcity is another factor that threatens its ability to recover which goes hand in hand with agricultural pesticide use reducing this species prey availability. Climate change causing unpredictable and unseasonal weather has seen the failure of young bats to reach breeding age. This species has a flight pattern that potentially brings it info conflict with onshore wind turbines. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | There is a need for the targeted reduction of harmful endectocide use within 4km of maternity roosts (in core sustenance zone), specifically with parasitic wormers in livestock reducing availability of dung beetle prey. In addition, evidence gaps need addressing on the impact of onshore wind turbines for this species and whether mitigation measures are successful in stopping fatalities. |
| 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: | The species forages in open areas of diverse high quality habitats at a landscape scale with connectivity e.g. woodland edge, small-scale farmland, unimproved grassland, over lakes/rivers. Habitat mosaics are important for the species to support a greater diversity of available prey, providing increased availability of quality foraging habitat. The species benefits from organic cattle grazed pasture and insect-rich edge foraging habitats, and a reduction in pesticide use, particularly endectocides, is important. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Structured - insufficient |
| Species Comments: | The continuation of the legal protection of serotine roosts is vital in avoiding a decline in this species. Although this species is generally widespread in the southern half of England, it is largely absent from some areas and where it is found it is always at low levels or under-recorded. In the south east of England the reasons for apparent declines need to be understood and addressed. Across parts of Kent increases in the availability and quality of species rich (unimproved) grassland appears to have aided foraging. More widely in England we know enough about its needs and threats to assist recovery with important species specific measures. More work on niche breadth and sonogram confusion is required. |
Key Actions
Key Action 1
Proposed Action: Targeted advice to stock farmers/landowners to reduce harmful endectocide use within 4km of maternity roosts (in core sustenance zone). Whilst the reduction in use of pesticides could be deemed a wider measure that would benefit this species, there is a specific issue with parasitic wormers in livestock reducing availability of dung beetle prey.
Action targets: 6. Recovery solutions trialled
Action type: Special (in situ) measure
Duration: 6-10 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments: The advocacy of this measure needs to be trialled at around 20 sites over a period of time to assess the conservation impact of this approach. Although we have 3-5 years as duration, the monitoring of the species roosts in question will take a longer period of time to show any change in trend. See also similar needs for greater horseshoe bat and lesser horseshoe bat.
Key Action 2
Proposed Action: The impact on this species of onshore wind turbines is unclear. Data from ongoing monitoring following mitigation measures needs to be assessed to ascertain whether it is being successful in stopping fatalities.
Action targets: 4. Autecology and pressures understood
Action type: Pressure mitigation
Duration: 2 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments: This action could be grouped in with the same needs for noctule, Nathusius' pipistrelle, soprano pipistrelle and Leisler's bat. It would take the joint funds to carry out this work.
Key Action 3
Proposed Action: Investigate regional variations and range accuracy. This species appears to have undergone a decline in the south east of England. Across parts of Kent increases in the availability and quality of species rich (unimproved) grassland appears to have aided foraging. More needs to be understood about the reasons for the regional variations in trends that are appearing and their cause if further declines are to be prevented. It is possible there is a link to climate change. It would also be necessary to improve the acoustic discrimination of serotine by BCT's Sound Classification System to ensure range data is robust.
Action targets: 4. Autecology and pressures understood
Action type: Habitat management
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments: More research is needed to understand the causes of regional variations in population trends and range shifts, including potential links to climate change. For example, the species appears to have undergone a decline in the southeast of England. Knowledge gaps concerning EBLV1 and roost use (maternity, hibernacula, and mating) also need addressing to inform this understanding. Robust data are essential and can be provided by improving the acoustic discrimination of serotine by BCT’s Sound Classification System.
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.