How Bats Survive Scottish Winters
Most people in Scotland only think about bats in summer, but they remain active throughout the winter in surprising ways. Winter in Scotland is long, cold, and unpredictable, which means bats use several survival strategies to cope with low temperatures and scarce food . Understanding seasonal behaviours helps you recognise when bats need space, when to report unusual sightings, and why winter roosts are such an important factor in bat conservation.
All of Scotland’s bat species feed on insects. When temperatures fall, flying insects become scarce, making normal activity impossible to fuel. Long nights, cold winds, and fluctuating weather conditions mean that conserving energy is essential if bats are to survive until spring.
What is torpor and why do bats use it?
Bats use a special state called torpor to save energy. During torpor, their body temperature, breathing rate, and heart rate all drop to very low levels. This allows them to save large amounts of energy over winter (and during the day in summer). Torpor can last for a few hours on a mild winter day or continue for several days during colder spells.
People sometimes imagine that bats hibernate in a single long, unbroken sleep. In reality, Scottish bats shift in and out of torpor many times through the winter. This flexibility allows them to respond to changing weather conditions and move if their roost becomes unsuitable.
Even though bats can and do move in and out of torpor through winter, there is a significant energetic cost. It is always illegal to disturb a hibernating bat.
Choosing the right winter roost
Winter roosts must stay cool but frost free, sheltered, and undisturbed. In Scotland this includes tree cavities, stone buildings, bridges, old tunnels, and underground spaces (natural and man made). These places provide stable temperatures that prevent bats from warming up too quickly or becoming too cold.
Roosts are not always used by many bats at once. Winter often leads to small groups or even single bats sheltering wherever conditions are most reliable. One winter roost (also called a hibernaculum) we have helped to protect was at Middleton Quarry - read more about here.
Do bats fly in winter?
Although winter is the quietest time of year, occasional bat activity is normal. When temperatures rise for a short period, bats may wake and search for winter active insects. Mild evenings can trigger brief feeding flights that help them top up their energy reserves. Bats may also fly during the day if the conditions are mild, insects are flying, and they need to top up their reserves. These sightings can be surprising, but they do not usually indicate that something is wrong.
If a bat is found during severe weather or is struggling to fly, it may need help. In these situations, contacting Bat Conservation Trust’s helpline or a local wildlife rescue is the safest option.
Why winter matters for bat conservation
Winter survival determines the strength of bat populations in spring. Disturbance at roosts can cause bats to waste valuable energy by waking too often or moving repeatedly. Even small increases in energy use can make survival less certain. Protecting winter roosts, keeping disturbance to a minimum, and reporting unusual sightings all help contribute to long term conservation.
Milder winters in Scotland are changing the conditions in hibernacula too, which places even more pressure on our bats at the hardest time of year.
How you can support bats this winter
Most winter support comes from awareness. Knowing where bats might be sheltering, avoiding work that would disturb hidden roosts, and sharing accurate information with neighbours all help reduce risk. People who enjoy wildlife recording can also report winter sightings through trusted platforms, which helps build a clearer picture of seasonal bat behaviour across Scotland.
Bats face many challenges during the coldest months, yet they remain remarkably well adapted to Scotland’s climate!
References
Bat Conservation Trust 2023. Bat Surveys for Professional Ecologists. Bat Conservation Trust, London.
Bat Conservation Trust 2024. Helpline Advice Resources. Bat Conservation Trust, London.
NatureScot 2020. Bats: Licensing and Guidance. NatureScot, Inverness.