Bats in Clausentum Fen

Bats are regular visitors to the Fen.They feed on insects, especially those associated with water, and will fly up and down streams and rivers looking for prey. Although visible at dusk they are difficult to tell apart by sight, but they can be identified using a bat detector. This is an electronic device which picks up the ultrasonic sonar pulses, which are too high a frequency for us to hear, and converts them into a series of audible clicks. Each species has a different pattern which can be recognised.

There are currently four species of bat known from the Fen. Click on their names to find find more information, including their call as heard on a bat recorder.

  • Pipistrelle (Picture above right)
  • Daubenton's
  • Noctule
  • Brown long-eared (Picture above left)

  • Encouraging bats in the Fen

    Bats feed on insects, mostly from the streams. The insect life of the streams depends on healthy vegetation (the 'stream macrophytes') which in turn depend on fast-flowing and well lit water. It is a priority in our management plan to restore these conditions.

    Bats also need somewhere to roost and the use of bat boxes to provide shelter can provide this. We have taken advice from bat conservation organisations about the type and siting of appropriate boxes and have installed some in the fen. Three bat boxes are placed where the waters of the Itchen, Lockburn, Floodstoc and Keats' Walk are closest together. They are impossible to see from inside the Fen but are clearly visible from Keats' Walk. Bats like their boxes to have adequate hanging space for maternal roosting in the summer, riverside dining, free from predator or bird access and with clear flight paths for the pups to start flying.

    Pipistrelles are the commonest and most widespread of all British bat species. There are two very similar species, common pipistrelle and soprano pipistrelle. Pipistrelles are the bats that you are most likely to see. They appear fast and jerky in flight as they dodge about pursuing small insects which the bats catch and eat on the wing. A single pipistrelle can consume up to 3,000 insects in one night!

    Flight path:

    Click here for an information leaflet about the Pipistrelle.

    Daubenton's bat is a medium-sized species. It has a steady flight, often within a few centimetres of the water surface and is reminiscent of a small hovercraft. They usually take insects from close to the water and have even been seen taking prey directly from the water surface.

    Flight path:

    Click here for an information leaflet about Daubenton's bat.

    The Noctule is one of the largest British species and is usually the first bat to appear in the evening, sometimes even before sunset. Noctules have a characteristic powerful, direct flight on narrow pointed wings.They fly in the open, often well above tree-top level, with repeated steep dives when chasing insects.

    Flight path:

    Click here for an information leaflet about the Noctule.

    Brown long-eared
    As well as catching insects in free flight, brown long-eared bats are gleaners, often flying slowly amongst foliage, picking insects off leaves and bark. Their broad wings and tail allow slow, highly manoeuvrable, hovering flight. Sometimes they land on the ground to catch insects or to shift them into a controllable position in the mouth, and they are even able to take insects from lighted windows. Their flight often includes steep dives and short glides.

    Flight path:

    Click here for an information leaflet about the Brown long-eared bat.