Bats

Here’s a brief introduction to the various species of bats that we have observed on the farm.

Daubenton’s Bats

Some info about the Daubenton’s bats.
A medium sized bat, who likes to hunt low over water, often skimming the water with its feet. They are found in a belt that stretches from the UK in the west to Japan in the east. They often roost in woodland close to water and live off insects. The UK population is considered stable.

  • Latin Name – Myotis daubentonii
  • On farm ID certainty – Certain (visual & sonogram confirmation)
  • Typical Flight – Quick flight, very low over water
  • Peak Frequency of Calls – around 48kHz
  • Typical Call Duration – 6 or 7ms

Audio Samples (from Foel Friog)

Samples are recorded with a frequency division bat detector, reducing the frequency of the calls 10 fold.

  • Sonagram (actual on farm recording, pulse repetitions of 12.25 pulses/s)
  • Peak Freq. Graph (on farm analysis showing a 47.4kHz peak)

Video

Infra-red illumination was used in the production of this video
and a sound overlay was recorded with a frequency division bat detector, reducing the frequency of the calls 10 fold.

Lesser Horseshoe Bats

Some info about the Lesser Horseshoe bats.
A small bat, found in parts of Europe including the UK. They are typified by the structure around their nose, which helps with echo-location. Small insects, especially midges, are their favourite food. The UK population is in decline due to habitat disturbance and insecticide use.

  • Latin Name – Rhinolophus hipposideros
  • On farm ID certainty – Certain (visual & sonogram confirmation)
  • Typical Flight – Fast & agile often low to the ground. We’re sometimes circled by them hunting for midges.
  • Peak Frequency of Calls – about 109kHz (highest of the British bats)
  • Typical Call Duration – around 40ms

Audio Samples (from Foel Friog)

Samples are recorded with a frequency division bat detector, reducing the frequency of the calls 10 fold.

  • Sonagram (actual on farm recording, 37ms call duration. Ignore ~50kHz background noise.)
  • Peak Freq. Graph (on farm analysis showing a 108kHz peak)

Video

None available

Noctule Bats

Some info about the Noctule bats.
A large British bat found across Europe, Asia and N. Africa. These woodland dwellers are also early risers and can be seen diving after insects from high in the canopy. The UK population is considered stable.

  • Latin Name – Nyctalus noctula
  • On farm ID certainty – Probable (distant visual & weak sonogram only)
  • Typical Flight – Fast high flight near tree tops, diving after prey.
  • Peak Frequency of Calls – circa 21kHz
  • Typical Call Duration – around 20ms

Audio Samples (from Foel Friog – Noctule & Pipistrelle)

None available

  • Sonagram (on farm recording)
    None available
  • Peak Freq. Graph (on farm analysis)
    None available

Video

None available

Pipistrelle (Common) Bats

Some info about the Common Pipistrelle bats.
A small but common bat in the UK. The fly eating Pipistrelle is found in various habitats across Europe, Asia & N. Africa. The UK population is thought to be increasing.

  • Latin Name – Pipistrellus pipistrellus
  • On farm ID certainty – Certain (visual & sonogram confirmation)
  • Typical Flight – Quick flight with rapid direction changes, often along hedgerows.
  • Peak Frequency of Calls – c. 46kHz
  • Typical Call Duration – about 6ms

Audio Samples (from Foel Friog)

Samples are recorded with a frequency division bat detector, reducing the frequency of the calls 10 fold.

  • Sonagram (actual on farm recording)
  • Peak Freq. Graph (on farm analysis showing a 46.7kHz peak)

Video

None available

Pipistrelle (Soprano) Bats

Some info about the Soprano Pipistrelle bats.
Soprano Pips are even smaller than their Common relation. They enjoy catching mosquitoes & midges above damp locations. Their voratious appetite can see several thousand midges eaten per individual – each night – and that makes me very thankful to have them around! Whilst commonplace throughout Britain, it seems unclear as to whether or not the UK population is stable or declining.

  • Latin Name – Pipistrellus pygmaeus
  • On farm ID certainty – Highly Probable (strong sonogram variation from Cmn Pips)
  • Typical Flight – Fast, dancing flight in pursuit of insects; often along hedgerows & woodland edges.
  • Peak Frequency of Calls – about 55kHz (higher than Cmn Pips)
  • Typical Call Duration – around 6ms

Audio Samples (from Foel Friog)

Samples are recorded with a frequency division bat detector, reducing the frequency of the calls 10 fold.

  • Sonagram (actual on farm recording)
  • Peak Freq. Graph (on farm analysis showing a 54.9kHz peak)

Video

None available

 

Further information about UK bats can be found at the Bat Conservation Trust website.

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