Serotine bat

Eptesicus serotinus

  1. Wildlife
  2. Mammals
  3. Serotine bat


One of largest bat species in the UK and one of the first bats to appear in the evening, often when it’s still fairly light. They roost more commonly in older buildings and are rarely found in trees. It’s likely they overwinter in buildings, too. Serotines forage on flies, moths, and larger beetles such as chafers and dung beetles.

How to identify

The serotine has a distinctive flight pattern with a slow flapping motion and short glides, often making steep descents. It flies at tree-top height and also forages around street lamps. It has long, dark brown fur and a pale yellow/brown belly. The wings, nose and ears are dark brown/black.

Where to find it

A less common species in the UK, it is found south of a line from southwest England and south Wales across to The Wash.


When to find it

  • April
  • May
  • June
  • July
  • August
  • September
  • October

How can people help

Because it roosts primarily in houses declines maybe due to chemicals used in timber treatment and also disturbance by building works. Also decline in habitat where prey items are found. The Wildlife Trusts manage many nature reserves for the benefit of all kinds of wildlife. You can help by supporting your local Trust and becoming a member; you'll find out about exciting wildlife happenings, events on your doorstep and volunteering opportunities and be helping local wildlife along the way.

Species information

Common name
Serotine bat
Latin name
Eptesicus serotinus
Length: 58-80mm Wingspan: 320-380mm Weight: 15-35g Average lifespan: up to 19 years
Conservation status
Least concern but all bats are protected in the UK under the Wildlife and Countryside Act, 1981.