The acoustic identification of small terrestrial mammals in Britain

Water Vole. Liz Cutting

Author(s): Newson, S.E., Middleton, N., & Pearce, H.

Published: December 2020   Pages: 10pp

Journal: British Wildlife Volume: 32

View the article

Britain is home to several species of small mammals, which include rats, mice, voles, dormice and shrews. All of these are difficult to observe in the wild, and it is usually necessary to capture them to confirm their presence. By describing the vocal repertoire of small mammals in Britain, research published in British Wildlife by a team led by the BTO provides new possibilities for sound identification to be used as a non-invasive survey method.

This has considerable potential to help conservation efforts by providing a cost-effective and robust method for detecting the presence of small mammals (e.g. Hazel Dormice in woodland, Brown Rats on seabird islands), which could be followed up with more intensive survey work if needed.

It is likely that large volumes of data on small mammals are already being collected incidentally, but probably unknowingly, across Britain by bat workers using bat detectors. To maximise the value of bat surveys, the BTO Acoustic Pipeline improves on the sound identification of bats, whilst also providing results for small mammals and other species groups.

For the full article, see British Wildlife Volume 32, Number 3, December 2020.

Download a zipped file containing original .wav audio clips (ZIP, 91MB) accompanying the publication.

Sample audio clips

Listen to sample audio clips of species below, processed to be audible:

Wood mouse

Apodemus sylvaticus

001 A sylvaticus typical recording 30-40kHz

002 A sylvaticus some calls exceed 65kHz

003 A sylvaticus calls exceed 65kHz

004 A sylvaticus inverted v shape calls 60-65kHz

005 A sylvaticus calls below 30kHz

Yellow-necked mouse

Apodemus flavicollis

006 A flavicollis calls between 45-59kHz

007 A flavicollis typical recording calls 30-40kHz

008 A flavicollis u shaped call 30-45kHz

009 A flavicollis typical recording calls 30-40kHz

010 A flavicollis higher frequency calls 45-59kHz

House mouse

Mus musculus

015 M musculus including high frequency calls

016 M musculus variation high frequency calls

017 M musculus low frequency calls

018 M musculus typical recording

Harvest mouse

Micromys minutus

019 M minutus typical recording

020 M minutus typical recording variation

021 M minutus typical recording variation

022 M minutus typical recording variation

023 M minutus inverted u shape calls

024 M minutus inverted u shape calls

Brown rat

Rattus norvegicus

025 R norvegicus CF calls 22kHz

026 R norvegicus typical calls 45kHz

027 R norvegicus less typical CF calls 30kHz

028 R norvegicus less typical calls 60kHz

029 R norvegicus less typical abrupt frequency changes

030 R norvegicus less typical short calls 22kHz

Black rat

Rattus rattus

031 R rattus typical recording CF calls 23kHz

032 R rattus less typical call 30kHz

033 R rattus short calls 30kHz

034 R rattus typical calls of 45kHz

035 R rattus less typical CD calls

036 R rattus lower frequency calls

Hazel dormouse

Muscardinus avellanarius

037 M avellanarius call sloping upwards 30kHz

038 M avellanarius typical recording call sloping upwards

039 M avellanarius typical recording variation

040 M avellanarius higher frequency example call sloping up

041 M avellanarius inverted v shaped calls

042 M avellanarius low frequency call sloping up

043 M avellanarius complex call sequence

044 M avellanarius male advertisement calls

045 M avellanarius complex calls variation

Water vole

Arvicola amphibius

046 A amphibius typical recording

047 A amphibius similar to R rattus

048 A amphibius less typical with abrupt frequency change

049 A amphibius typical recording with step change

050 A amphibius complex sequence

051 A amphibius less typical call no step

052 A amphibius higher frequency calls

053 A amphibius higher frequency calls with step

Field vole

Microtus agrestis

054 M agrestis typical recording below 20kHz

055 M agrestis calls at 20kHz

056 M agrestis high frequency call

057 M agrestis calls between 30-40kHz

Bank vole

Myodes glareolus

011 M glareolus typical recording calls 30-40kHz

012 M glareolus call_variation 1

013 M glareolus call variation 2

014 M glareolus call variation 3

Common shrew

Sorex araneus

058 S araneus less typical calls sloping down

059 S araneus typical calls five harmonics

060 S araneus typical recording consistent calls

061 S araneus less typical example variable calls

Pygmy shrew

Sorex minutus

062 S minutus typical recording sloping calls multiple harmonics

063 S minutus typical recording sloping calls complex start

064 S minutus typical recording sloping calls multiple harmonics

065 S minutus complex call otherwise typical recording

Water shrew

Neomys fodiens

066 N fodiens typical recording

067 N fodiens typical recording

068 N fodiens typical recording strongest harmonic ending 10kHz

069 N fodiens typical recording


Thanks to the co-authors -

  • Neil Middleton (neil.middleton [at] is the owner of BatAbility Courses & Tuition, an organisation that focuses on the development of people within the ecology sector. 
  • Huma Pearce (huma [at] is a freelance ecologist specialising in mammals and urban ecology.

The work on this article was funded by JNCC and the Esmée Fairbairn Foundation.

British Wildlife 32 Small Mammals article cover
Staff Author(s)

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