Bats and their habitats
There are seventeen resident breeding species of bat in the UK, varying in size from our two smallest and most common Pipistrelle bats (which can fit into a match-box) to our two largest bats, the noctule and the greater horseshoe. Bats are most vulnerable to harm if disturbed during hibernation or the maternity period. However, all bats and their roosts are protected from harm and disturbance at all times by EU and UK law. Bats’ foraging habitats also receive some protection within the planning system.
All UK bats feed on insects, although they each have subtly different diets and are therefore best observed foraging where insects are most abundant: primarily, waterbodies and woodland, gardens and parks, and along hedgerows and tree lines. Bats often use linear features within the landscape such as hedgerows to navigate.
The calendar year for a bat usually starts with hibernation and they only emerge in the spring as the weather ameliorates. In the early summer, females form maternity roosts where most give birth to a single pup, usually in June or July. Just a month or so later, the juveniles are volant (i.e. able to fly) and these roosts will then often begin to disperse. Shortly after this, bats will begin to mate. Some species will head to communal ‘swarming’ sites, where mating and other social exchanges will occur between multiple bats on favourable nights through the autumn.
Often these sites are then used for hibernation, which typically takes place in an undisturbed place with a cool climate where bats will significantly lower their metabolic rate. Bats use very little energy when undisturbed, although some will occasionally stir on milder nights, perhaps even to mate.