The common pipistrelle Pipistrellus pipistrellus
An Fheascarluch Choiteann
© Phil Richardson
By far the most commonly seen bat in our evening skies, the common pipistrelle is frequently found foraging in urban as well as rural habitats preying on the insects attracted to streetlights and frequently returning to the same areas to feed night after night. It is easily seen as it tends to fly at head height.
Weighing just 4 to 8 grammes the species is often mistaken for a baby bat when found grounded by the public, as they look much bigger when seen in flight. They are capable of squeezing through tiny cracks and, in summer, are frequently found roosting in the eaves of buildings or behind hanging tiles, lead flashing etc. They also make use of bat boxes and tree holes. In winter, they hibernate in stone buildings, trees, walls etc. and rarely underground.
As with the other Irish bat species, the common pipistrelle produce only one young, usually in June, and the juvenile is already flying by its fourth week. The first year is a difficult one as the young bat has to learn to fly, feed and find safe roost sites. It also has to accumulate enough stored body fat to survive its first winter. Most die in this first season due to accidents, being cat caught or malnutrition. Should the juvenile survive to the following spring, then its lifespan is usually four years in the wild although the longest lived pipistrelle survived for 16 years in Czechoslovakia.