Bats
Chiroptera
Íaltogaí / Scíatháin leathar
What exactly are bats?
Like dogs, cats and humans, bats are mammals; i.e. they have hair or fur, and give birth to live young which they feed on milk. Bats are special in that they are the only mammals capable of true powered flight (there are other mammals which can glide but not fly). The wing of a bat is a membrane of thin skin, stretched between its very long fingers. Bats originated more than 50 million years ago, and are one of the most successful groups of mammals, with nearly 1000 species. They are mostly nocturnal.
How many kinds of bat do we have in Ireland?
We have 10 different species of bat in Ireland:
Leisler’s Bat
Common Pipistrelle
Soprano Pipistrelle
Nathusius’ Pipistrelle
Brown Long-Eared Bat
Daubenton’s Bat
Natterer’s Bat
Whiskered Bat
Brandt’s Bat (only a few locations)
Lesser Horseshoe Bat (This is the only species that does not occur in Wicklow Mountains National Park)
All the bats in Ireland belong to the group called micro-chiropterans, which are the small bats that eat mostly insects. The other group is the mega-chiropterans, the big bats that live in the tropics and mostly eat fruit and nectar. Because bats can fly, we can assume that they reached Ireland by themselves - also, it is unlikely that humans would introduce bats on purpose.
Are bats dangerous to people?
None of our bats cause us any harm. Unfortunately, because bats are such unusual animals, a number of myths about them have grown over time..
- Bats are not blind—they can see as well as any other mammal. But when they are hunting, they use an extra sense called echolocation.
- Bats do not turn into vampires and suck our blood! There is a kind of bat called the vampire bat, which lives in South America and takes small amounts of blood from cows, horses and birds, but all Irish bats eat insects.
- Bats do not get caught in our hair! Their sense of direction and skill at flying are way too good for that, and anyway why would a bat want to get caught in your hair?!
Do bats live in groups?
Bats are relatively social animals, with family groups usually sharing roosting sites (where they sleep) for warmth. Some species, like the pipistrelles, may live together in maternity roosts up into the hundreds or even a thousand during the summer.
Do bats have territories?
Males of some species are territorial in the mating season (autumn), and establish mating roosts. During the but do tend to use the same roosting and feeding areas from year to year and generation to generation.
What do bats eat?
As mentioned earlier, all Irish bats eat insects. Even our largest bat, Leisler’s bat, only has a wingspan of 30cm and lives entirely on flies, moths and midges. Different bats have different specialities, e.g. Daubenton’s bat flies low over water to snatch insects from the surface, and the Long-Eared bat sweeps silently through trees to glean spiders off the leaves. Bats are very beneficial in taking large numbers of insects that may be pests - 1 tiny pipistrelle may eat 3000 midges in 1 night!
How does echolocation work?
Echolocation literally means ‘finding things with echoes’. The bat sends out a very high, very fast squeaking through its mouth or nose. The sound waves hit both obstacles and potential prey, and bounce back to the bat’s sensitive ears, where they are picked up and converted into a kind of ‘sound picture’ of the bat’s surroundings.
These sound waves are inaudible to most humans, but are so loud to the bat that it has to dislocate its earbones every time it ‘shouts’! Because each bat species has a different call frequency (from 25-120 Kilohertz), we can tell what bats are in an area by picking up the calls on a bat detector, which converts them into a frequency we can hear.
How long do bats live?
For such small animals, bats are quite long-lived, with the average age being 5 to 7 years.
Do bats have any predators?
Not many other animals prey on bats, but owls will occasionally catch them. Cats have also been known to hunt bats, usually by lying in wait outside the exit of a roost, and catching the bats with their paws as they try and fly out for the night.
Do bats hibernate?
Yes. Because of the cold and the lack of flying insects over winter, our bats must hibernate to survive through to spring. Most bats hibernate singly or in small groups, in gaps in buildings or in hollow trees. Only lesser horseshoe bats hang upside down; all other Irish All the body processes slow down, and while some bats like the common pipistrelle can be active on warmer days, most remain inactive all winter.
When are baby bats born?
Baby bats are born in June & July, when it is warm and there are plenty of insects for the mother to feed on. Usually only one baby is born to each mother, much like humans, and it clings onto its mother, or the wall when the mother is out. In some species hundreds of mothers may gather together in a maternity roost. The young are fed on milk for the first 8 weeks or so, but are able to fly before that, at about 6 weeks of age. Young bats practice for flight by flapping and stretching their wings inside the roost.
Are bats protected?
All bats are protected under the Wildlife Act. Because bat’s daytime roosts are so important to their survival, all such sites are also protected. These roosts include old buildings, caves, bridges, hollow trees and even modern houses. It is illegal to harm bats or to move them elsewhere, or even to alter a site where bats are present, as this may prevent them getting out or in. Bats in this country do not cause any structural damage or carry diseases. You can encourage bats in your area by putting bat boxes up on trees.