It’s peak season for bat maternity roosts, where bats gather to raise young. Maternity roosts are really important. If you look in the right place, at the right time, you might find one.
Bat maternity roosts
Female bats gather in maternity roosts, from spring into summer. To give birth and raise their young. Mothers give birth to a single bat pup, or occasionally twins. Pups are born blind, helpless, and without fur. They are completely dependant on their mothers, who will feed them for 4 – 5 weeks. Until they are strong enough to fly, and feed themselves. She will stay with them during the day, and at night leave to forage, before returning to feed them.
The pups are left in the roost with other pups, forming a crèche. With mothers taking turns to look after each others young, between bouts of feeding. Which is one of the advantages of living in a colony.
The size of maternity colonies varies. Pipistrelles form large colonies, sometimes with a thousand bats. Long eared bats have much smaller colonies, with 10 – 20 bats. Bats are quiet, do not chew cables, or cause a nuisance so you may not even realise you have a bat roost.
Bats begin to emerge from their roost shortly after sunset. In larger roosts you may be able to hear bats chattering before they leave. They may all leave one after the other, or from several places at the same time. Usually feeding nearby for a few minutes, before flying to their main feeding area. A single pipistrelle can take up to 3000 midges in a single night. And may return several times to feed her pup. Returning for the final time shortly before sunrise.
Bats can be seen flying around their roost entrances before going back in. This is the best time to see them. flying when it is almost light.
Males go out and do their own thing.
Male bats spend the spring and summer on their own. Going out to feed, and do their own thing. Building up supplies of fat, ready for winter. When they will go into hibernation. Female bats have less time to build up their body fat for winter hibernation. Because they use so much energy feeding their pups. They only start to put on weight after the pups have left the roost, and are independent.
The weather can play a big part in the survival of bats.
Maternity roosts are vulnerable. If the weather is bad, early in the year, the development, and birth, of pups can be delayed. Because of the lack of food. Leaving mothers less time, to gain weight, for hibernation. If weather is poor when pups are born, there may not be enough prey to feed them. And they may not survive.
As young pups start to get mobile, they are at their most vulnerable. Like toddlers, they will sometimes wander off when nobody is looking. Occasionally falling out of the roost, and unable to get back in. Leaving them open to attack from predators, like birds, and cats, and at the mercy of the weather.
You can help
You can help to protect bats at this vulnerable time. For bats, survival is already a difficult task, especially with our summer weather. We can’t do anything about the weather. But we can make sure, that we don’t make life more difficult. Many things which we do, as homeowners, can impact on bats. Lighting and noise close to a roost entrance; re-pointing walls, roof works; and our pets, can all have a massive impact on bat roosts. Mothers will abandon the roost if disturbed, leaving young pups behind.
Checking for roosts, before you make changes to a building, or cut down a tree in the garden. Will prevent roosts being damaged, and help to protect bat pups.
We can protect young bats from predators, and our pets, by finding roosts, and keeping an eye out for any young who have escaped, and can’t get back in. Cats will sometimes sit outside a roost entrance, waiting for bats to emerge. Last week we saw a cat on the roof of a house, at the apex! If you notice your cat, staring at a hole in the wall, every night at dusk, you may have a roost. Please do what you can to prevent them catching the bats.
finding maternity roosts
If you find a bat roost, please keep an eye on it. It can be really interesting to watch bats leaving, or returning. Dawn is a my favourite time to watch bat roosts, as bats will fly around outside the entrance before returning. It can be amazing to watch, particularly if their are lots of bats. And you might be able to stop cats catching them. It is worth letting your local bat group know about the roost. They might come and have a look, and tell you what kind of bats are living with you. Please remember that bats and bat roosts, are legally protected. Don’t go inside a loft, or climb a tree, where there is a roost. You could harm the bats, harm yourself, and get into trouble.
If you find an injured bat, or an escaped bat pup, you can help by keeping them safe, and calling the Bat Conservation Trust. They will give you advice and may send out a volunteer to help. The bat helpline number is 0345 1300 228. Visit the BCT website for more information, lots of interesting bat facts, or to become a member. your donation will go toward helping bats.