Living Organisms / Animalia / Craniata / Mammalia / Chiroptera / Vespertilionidae / Nyctalus / Species
Nyctalus leisleri - Lesser noctule (Click photographs/illustrations: full picture & further details)








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General and References

Alternative Names (Synonyms)

  • Hairy-armed bat
  • Leisler's bat
  • Vespertilio leisleri Kuhl, 1818; Germany.

Alternative species names (the second part of the binomial species names): [Genus] dasykarpos; [Genus] madeirae; [Genus] pachygnathus; [Genus] verrucosus; (B141).

Names for new-borns / juveniles

Names for males --
Names for females --

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General Appearance

Medium-large bat. Shaggy fur, variable golden to dark rufous brown, with visibly darker hair bases, dark bulbous face, squarish ears.(B142, B167).

Similar Species

Other bats. Distinguished by:
  • Simple nose shape (no horseshoe)
  • Ears well separated from one another at base
  • Post-calcarial lobe present on membrane
  • Forearm 37-47mm.
  • Long shaggy hair, dark at base and pale at tips.
  • (B167).

Very similar to Nyctalus noctula - Noctule, but smaller (forearm less than 48mm long), with dorsal hairs distinctly paler at tips than at base, rather than uniform in colour (B142).

Sexual Dimorphism Males slightly smaller than females (B142)

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Species Author

Debra Bourne

Major References

B51, B52, B141, B142, B143, B147, B167, B221

Husbandry references:

(UK Contacts)

(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

  • --

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TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

  • Insectivorous Bats (Microchiroptera)

Specific Needs Group referenced in Management Techniques

  • Insectivorous Bats (Microchiroptera)

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Husbandry Information


Individual Techniques linked in Wildpro

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Appearance / Morphology

Measurement & Weight

  • Head-body length 54-64mm (B142).
  • Forearm 39-47mm (B142).
  • Wingspan 280-340mm (B142).
Height --
Adult weight General 11-20g (B142).
Male --
Female --
New-born weight About 5g (B147).
Growth rate To adult size by 6-7 weeks (B147).

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General Skull: Condylobasilar length 15.2-16.0mm (B142).


Ears: squarish, well separated, short (12-13mm long). Tragus very short, mushroom-shaped. (B142, B167).

Dentition (Teeth) I 2/3, C1/1, P2/2, M3/3 (B142).
Eyes --

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Legs and Tracks

Wings narrow, pointed. Membrane thick, opaque (B142).
  • Forearm 39-47mm (B142).
  • Wingspan 280-340mm (B142).

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  • Post-calcarial lobe of membrane prominent (B142).

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Coat / Pelage

Adult Female Dark fur with light tips and dark bases to individual hairs.
  • Dorsal: variable golden to dark rufous brown; dark brown hair bases.
  • Ventral: paler slightly grey brown.
  • Face and ears: skin very dark brown/blackish.
  • Membranes: very dark brown/blackish.

(B142, B167)

Variations (If present) --
Moult --
New-born / Juvenile --

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Neonate (New-born) Characteristics


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Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)


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Life Stages / Natural Diet / Physiology

Reproductive Stages

Breeding Season --
Oestrus / Ovulation --
Gestation / Pregnancy
  • 70-75 days (B147).
Parturition / Birth --
Neonatal development
  • 6-7 weeks: weaned, reach adult size (B147).
Litter size --
Time between Litters / Litters per year --
Lactation / Milk Production --
Sexual Maturity --
Longevity --

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Natural Diet

Large insects (B142).

Most important dietary items may vary depending on geographical area:

  • Ireland and England: Diptera (Nematocera and Cyclorrhapha); also Coleoptera, Trichoptera, Lepidoptera .
  • Germany: Lepidoptera, Nematocera and Neuroptera may be important in diet (at least locally).


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Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Temperature --
Pulse --
Respiration --
Faeces --
Haematology / Biochemistry --
Chromosomes 2n = 46, FNa = 50 (B142).
Other --

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Feeding Behaviour

  • Forage over open areas.
  • Catch and eat prey in flight.

(B142, B143)

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Parental Behaviour


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Social Behaviour / Territoriality

Intra-specific --
Inter-specific Sometimes individuals found in Nyctalus noctula - Noctule colonies in southern Bohemia (B142).

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Sexual Behaviour

  • Promiscuous.
  • Breeding males occupy and defend roost site, flying out of roost several times each night to spend a few minutes calling to attract females.

(B52, B142).

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Predation in Wild


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Activity Patterns

  • Flights straight, fairly fast with shallow dives.
  • Mainly fly at level of tree-tops, also low over forest ponds and brooks.


  • Emerge from roost at or soon after sunset.
  • Activity peaks probably dusk and dawn.


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Habitat and Range

General Habitat Type

  • Forests: deciduous and coniferous, also parklands, urban areas (B142).
  • Open areas used for foraging (B143).

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Nests / Burrows / Shelters

  • Tree holes (normal in continental Europe).
  • Bat boxes in conifer plantations.
  • Buildings (commonest sites in Ireland).

Hibernacula: probably hollow trees, buildings, occasionally rock crevices (no records of sites for Ireland).

(B142, B143).

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Distribution and Movement (Migration etc.)

Normal Palearctic - western Europe to Iran, eastern Afghanistan, western Himalayas and Uttar Pradesh in northern India, at 79 40' East; also north-western Africa, Madeira, Canary Islands.
  • Europe: from Britain and Ireland eastwards. Not found in Iceland, Denmark, Norway, most of Sweden, Finland, Estonia, northern Russia.

(B51, B143, B147)

  • Britain: rare. Ireland: abundant (B142)


  • Migratory, with flights of several hundred kilometres recorded (B142) and 1245km maximum (Russia to Turkey) (B143, B147).
Occasional and Accidental
  • Vagrant recorded Shetland (B142).


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Intraspecific variation

Two subspecies recognised:
  • Nyctalus leisleri leisleri
  • Nyctalus leisleri verrucosa Bowdich, 1825. (Madeira). Smaller than nominate form.


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Conservation Status

Wild Population -
  • Irish population (considered stronghold of world population) appears stable, but other populations vulnerable. (B143)

  • In Britain: native, "widespread but scarce in Britain". Pre-breeding population estimate of about 10,000 including 9750 in England, 250 in Scotland, 0 in Wales. Population estimate was "based on a very limited amount of information for the species" although additional knowledge "may not necessarily have made a substantial difference to the estimate". (B221)

General Legislation
  • Bern Convention, Appendix II
  • Bonn Convention, Appendix II.
  • EU Habitats and Species Directive, Annex IV


CITES listing --
Red-data book listing
  • Lower Risk - near threatened (B143, B147).
  • Exclusion from buildings used as nursery colonies (B143).
Captive Populations --
Trade --

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