Natterer’s Bat – Myotis nattereri

Taxon: Chiroptera

Habitat: Broadleaved Woodlands, Riparian, Hedgerows

Description: Medium sized Myotis bat with brown-grey dorsal fur ang grey-white under and ventral fur.

Origin & Distribution: Native. Widespread in the UK, however, they are sparser in Scotland and Northern Ireland than in England and Wales. Found on the island of Arran, the Isle of Man, and the Isle of Wight. Historically found on Islay, however, recent records have failed to identify them.

Diet: High in flies, particularly dungflies and midges. Feed on the wing (hawking) and off surfaces (gleaning).

General Ecology: The Natterer’s bat is commonly associated with trees, particularly broadleaved woodlands, tree-lined river corridors, trees in parklands, and hedgerows adjacent to pastures. They have been observed foraging over grass and thistles on roadsides, in the open over pastures and meadows, and using mature Corsican pine plantations in Scotland. Most commonly recorded species at swarming sites in the UK, with large catchment areas (20-60km radius).  Winter roosts may be found in underground sites such as canal and railway tunnels, caves, mines, and ice houses.

Breeding: Maternity roosts are located in trees, bat boxes, and buildings (barns, churches, and old dwelling houses). Tend to be situated within 500m of woodland, the size of the woodland does not appear to be important.

Conservation Status: The Natterer’s bat is registered as Least Concern in the UK and globally. These bats are benefited by an increased availability of broadleaved woodlands and bat boxes. However, traditional roosts are at threat due to barn conversions and encroaching urban developments. Prey, particularly dung flies, are changing in abundance due to hanbiata change and the effects of pesticides (specifically avermectins) on dung flora.

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Identification

Medium sized Myotis bat with brown-grey dorsal fur ang grey-white under and ventral fur. Main distinguishing features are the S-shaped calcar, the conspicuous fringe of short hairs along the edge of the tail membrane, and the long, sharply pointed tragus. Ears are relatively long, reaching a little beyond the tip of the muzzle if folded forwards. 

Identification Definitions

• Calcar: Ancle spur.
• Dorsal: back, or upper side of an animal
• Muzzle: Projecting part of face, including nose and mouth.
• Tail Membrane: Skin connecting the tail to the feet.
• Tragus: Piece of skin near the ear canal.
• Ventral: on or relating, to the animal’s underside.

Bat Detector

Range: 23-115 kHz

Most energy: 53 kHz

Average duration: 3.8 ms

Confusion Species

Difficult to identify conclusively on the basis of acoustic identification alone. Particularly, confused with Myotis myotis (greater mouse-eared bat).