The Noctule bat is the largest species of bat in the UK. They’re usually the first to appear in the evenings, often leaving their roosts before the sun sets.
|Scientific Name||Nyctalus noctula|
|Length||3.7cm – 4.8cm|
|Wingspan||32cm – 40cm|
|Weight||18g – 40g|
|Colour||Golden-brown fur with a light brown face|
|Habitat||Found dwelling in trees and rock fissures|
|Diet||Moths, chafer beetles, dung beetles, mayflies, and flying ants|
|Lifespan||4 – 5 years|
What Does the Noctule Bat Look Like?
The Noctule bat is the UK’s largest bat. Still, it only measures 3.8cm – 4.7cm from head to tail and weighs 18g – 40g. Its wingspan ranges from 32cm – 40cm.
Noctules have plush, chocolate brown fur which can change to reddish-brown as winter approaches. Their face and wings are quite dark.
Even though it’s the UK’s largest bat, you can hold the Noctule in the palm of your hand.
Where Do Noctule Bats Live?
Noctule bats are widespread across much of England, Wales and south-west Scotland. There a none in Ireland.
They’re tree dwellers and live in holes caused by rot or old woodpecker holes. They don’t often roost in buildings and if they do, it’s for a short time.
Trees and woodlandare important feeding habitats. In urban areas, you might also see them around street lamps feeding on the insects that are attracted to the light.
What Do Noctules Eat?
Moths, chafer beetles, dung beetles, mayflies, and flying ants are all staples of the Noctule bats diet.
Hunting starts earlier than other bats, often before sunset. They fly above the tree tops making repeated, steep dives to catch their prey which they eat mid-flight. They sometimes take food from the floor.
When Noctule bat hunt, they can reach speeds of 31mph, or 50 kph.
How Do They Breed?
Mating takes place between July and September. During this time, male Pipistrelles roost on their own and establish ‘courtship territories’. They attract female bats by singing social calls called ‘song flights’.
After mating, the sperm doesn’t fertilise the female’s egg until the following spring. This is called ‘delayed implantation’.
Females form maternity colonies of up to 75 bats in early summer, often in a roof space. After a gestation period of 44 – 50 days, they give birth to a single pup in June or July. Pups feed solely on their mother’s milk for the first 3 – 4 weeks. At around 4 weeks, young bats are able to fly and at 6 weeks old, they’re able to forage and hunt for themselves.
Females reach sexual maturity in 1 year. Males reach maturity in 2 years.
When and Where to They Hibernate?
Common Pipistrelles become less active at around October. By December, they are in full hibernation. They prefer to hibernate in buildings and bat boxes where they can take advantage of the warmth and shelter.
When temperatures start to warm up again at around March time, they emerge from their hibernation roosts. By May, they’re fully active again.
What Does Their Echolocation Sound Like?
Most sounds the Common Pipistrelle makes are above the range of human hearing. The only exception might be their social calls which some children might be able to hear.
A bat detector can pick up their echolocation calls between 45kHz – 70kHz.
Threats to the Common Pipistrelle
Populations of Pipistrelle bats have declined a lot in the last few decades. That said, Common Pipistrelle numbers have recovered in recent years.
Still, they face several threats, including;
- Reduced food supply – modern agriculture and the heavy use of pesticides is responsible for a huge decline in insect numbers. The very insects bats feed on.
- Modern building – house renovations often disturb bat colonies. Not only that, but chemically treated timber and insulation is often toxic to bats.
When and Where to See Them
The Common Pipistrelle is the second most common bat in the UK after the Soprano Pipistrelle. You can see them all over the UK and experts predict their numbers to be around 3 million.
They’re most active between April and September so this is the best time to see them. Have a walk around your garden or your local area at dusk. Chances are, you’ll see them flying around above your head, especially if you’re near water.