Bat Emergence Surveys
Clear, expert dusk emergence surveys to support planning decisions.
Determine whether bats are actively using a building or structure as a roost with a bat emergence survey from aLyne Ecology. Reliable, clear survey data, practical guidance and reporting from experienced bat ecologists.
In a nutshell
Seasonality: May to September
Survey type: Field survey
Report lead time: 2–3 working days (from survey completion)
Report validity: 12-18 months
What is a Bat Emergence Survey?
Bat Emergence Surveys, also referred to as Dusk Emergence Surveys, help to determine whether bats are actively using a building, structure or tree as a roost and, if bats are present, characterisation of the roost. The findings contribute to the determination of planning applications, and reports will provide information on how bats are using the site, what species are present and which roosting features are in use.
Usually following a Preliminary Roost Assessment (PRA), Emergence Surveys are carried out using specialist equipment such as bat detectors, infrared cameras and night-vision technology, by a suitably qualified and experienced ecologist.
When is a Dusk Emergence Survey required?
In most cases, Dusk Emergence Surveys are required if a PRA or Ground Level Tree Assessment (GLTA) identifies that a building, structure or tree could support roosting bats. The survey will help establish whether bats are actively using the site and whether proposed development works are likely to affect them.
Dusk Emergence Surveys are commonly recommended for:
- Buildings, structures or trees assessed as having low, moderate or high bat roost suitability during a PRA or GLTA
- Planning applications involving roof works, demolition, conversions or tree removal
- Sites where proposed works could affect bat roosts or commuting routes
- Proposed developments requiring more information to support planning decisions
The number of surveys required will depend on the level of bat roost potential identified during the initial assessment.
When can a Bat Emergence Survey be performed?
Bat Emergence Surveys can only be carried out during the active bat season. This means they’re usually possible between May and August, with one survey sometimes extending into September if appropriate.
Surveys begin approximately 15 minutes before sunset, continuing for at least 1 hour and 30 minutes after sunset, and must be carried out during suitable weather conditions.
Optimal Survey Season
Sub-Optimal Survey Season
Survey Not Possible
Bats: Dusk Emergency Surveys
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
Our Bat Emergence Survey process
Our process is carefully planned to gather reliable, responsible information on bat activity and roost use while keeping your project moving efficiently:
01
PRA review
We begin by reviewing the outcomes of the Preliminary Roost Assessment (PRA) to determine the number of surveys required and the most appropriate survey timings.
02
Survey scheduling
Emergence surveys are scheduled during the active bat season and in suitable weather conditions, in line with current bat survey guidance.
03
Surveys undertaken
Bat activity, species, emergence points and behaviour are recorded throughout the survey period, over the course of 1 to 3 visits.
04
Analysis & reporting
Following completion, recordings and observations are analysed by our ecologists, and a clear, planning-ready report is prepared to outline findings and recommendations.
01
PRA review
We begin by reviewing the outcomes of the Preliminary Roost Assessment (PRA) to determine the number of surveys required and the most appropriate survey timings.
02
Survey scheduling
Emergence surveys are scheduled during the active bat season and in suitable weather conditions, in line with current bat survey guidance.
03
Surveys undertaken
Bat activity, species, emergence points and behaviour are recorded throughout the survey period, over the course of 1 to 3 visits.
04
Analysis & reporting
Following completion, recordings and observations are analysed by our ecologists, and a clear, planning-ready report is prepared to outline findings and recommendations.
Why choose aLyne Ecology for your Bat Emergence Survey?
Our friendly team combines technical expertise with a supportive approach, delivering reliable Bat Emergence Surveys for responsible, efficient planning decisions.
Efficient coordination
Our organised in-house team works proactively to keep surveys progressing smoothly during the limited bat survey season.
Licensed bat ecologists
Our surveys are undertaken by appropriately licensed and experienced ecologists, working in line with the latest Bat Conservation Trust guidance.
Planning-ready reporting
You’ll receive concise, compliant reports which meet the standards set out by CIEEM and BS 42020.
High-quality delivery
All survey work, analysis and reporting is completed by our small but dedicated internal team, who can mobilise quickly to support you.
Get a quote for your Bat Emergence Survey
Work with our experienced bat ecologists for clear guidance and reliable survey reporting that keeps your project progressing smoothly through the active bat survey season.
Speak to us today to get more information on Dusk Emergence Surveys and how we can support you.
Contact details
info@alyneecology.co.ukGet a quote for your Bat Emergence Survey
Work with our experienced bat ecologists for clear guidance and reliable survey reporting that keeps your project progressing smoothly through the active bat survey season.
Speak to us today to get more information on Dusk Emergence Surveys and how we can support you.