Have you been asked for a bat hibernation survey by your local planning authority?
For a free quote or help with other bat surveys, ask for a quote from our ecological consultancy by filling out a quote form.
Planning delays in the winter months can stop development projects if ecological risks are left unaddressed.
Although a lot of people may think that ecological checks pause when the weather cools down, winter actually brings different legal obligations.
If your development site contains suitable cracks, cavities or underground voids, you need a bat hibernation survey to rule out disturbance to winter shelters before breaking ground.
Whether it’s spring, summer, autumn or winter, planning approval will be refused if you don’t show your local planning authority that the proposal won’t have negative impacts on protected British wildlife.
A bat hibernation survey works out if cold or humid features on your development site offer suitable conditions for hibernating bats to spend the winter months in torpor.
British bats drop their heart rate and body temperature to survive food shortages between late autumn and early spring, meaning that waking them up burns critical fat reserves.
It differs from other bat surveys, like the phase 1 preliminary roost assessment (PRA) and phase 2 bat emergence and re-entry survey (BERS). For instance, while summer work focuses on nursery colonies, winter surveys check if vulnerable roosting bats shelter inside cellars, ice houses, stone walls, deep tree hollows or quiet roofs during cold weather outside of the survey season.
The local council, conservation officer or planning ecologist will often request a winter assessment if a preliminary ecological appraisal (PEA) or preliminary roost assessment (PRA) flags any features with moderate or high hibernation potential.
Common triggers across development sites include:
A set process is followed in any bat hibernation survey based on the best-practice standards of the Bat Conservation Trust (BCT).
Our ecological consultants analyse the physical suitability of internal crevices and seasonal ultrasound patterns.
The approach for the survey effort is decided based on the site’s suitability rating. For instance, low-potential sites usually need a single winter visit, whereas moderate or high-suitability sites need two to three visits spaced roughly a month apart.
As bats hide deep inside narrow gaps, ecological surveyors use a mix of physical search tools, environmental monitoring and automated acoustics to account for sub-zero weather fluctuations.
Over the course of a bat hibernation survey, ecologists will conduct the following exercises:
As a starting analysis, an ecological consultant will carry out a walkover of the site using endoscopes, high-powered torches and specialist infra-red cameras to review dark recesses, cavity walls and deep voids.
For trees, it includes climbing or carrying out elevated inspections to check for rot holes. In any space, feeding remains, droppings and staining from urine or excrement will be used as evidence that bats are present.
Alongside static bat detectors, small environmental data loggers are used for tracking internal temperature and relative humidity in targeted locations.
The monitors are left in place for at least two weeks per visit during cold spells. In this time, they will record bat activity, log stable microclimates during temperature fluctuations, and track when animals briefly wake to drink or feed.
All sonograms recorded at the site are downloaded to differentiate typical crevice dwellers like soprano pipistrelles from rare woodland species, logging any subtle shifts in seasonal bat behaviour.
The findings from the survey are then compiled in a clear report, ready to be submitted to the local planning authority to support the planning application.
If you need to evaluate your development site’s suitability for bats and bat roosts in the winter months, it’s important that you arrange a bat hibernation survey before the winter window closes in March.
It could be that an initial assessment confirmed that bats are present on your site, but bat hibernation surveys are needed to measure activity outside of the active season.
Whatever the situation, if you need our help with hibernating bats, all you need to do is get in touch and arrange the necessary bat surveys from our team, booking ahead of time to avoid delays.
Each of the ecological consultants in our team comes with the experience, knowledge, licensing and training needed to complete a professional inspection, as well as static bat detectors and other highly specialised equipment.
With any type of bat survey, booking ahead of time is vital, as it means you can choose a date that fits with the survey season and works in your development plans.
From common pipistrelles to brown long-eared bats, our team has an advanced understanding of bats, ecological surveys and anything related to planning. If you’re unsure of what you need, simply get in touch for further information on what to do, what you need and when you need it.
If you want a free quote for a bat hibernation survey on your site, reach out to Arbtech, and we can give you a price and a date for evaluating natural and built structures for roosting bats. You can do this by calling, emailing, visiting our contact page or filling out a quote form on this page.
Editor at Arbtech, Rob is a content specialist who manages our ecology and arboriculture services copy to ensure it is accurate, up to date, and insightful for current and future clients.
Arbtech are your best asset when it comes to getting planning permission for your project. We cover the whole of the UK and we are waiting to get started on your project...
Get Your Free Quote
