Nathusius' pipistrelle in Great Britain & Ireland

Differentiating between pipistrelle species based on tooth morphology

On the upper tooth row, pipistrelle bats have 2 incisors, 1 canine, 2 premolars and 3 molars and on the lower tooth row, 3 incisors, 1 canine, 2 premolars and 3 molars. The two premolars present are names P² (the smallest) and P4 (the largest) and it is the position of the second premolar (P²) that is the most important feature separating Nathusius' pipistrelle from the Common or Soprano pipistrelles. The photograph on the right, taken by Mike Rendle of the Northern Ireland Bat Group, shows the upper tooth row of a Nathusius' pipistrelle viewed from the side outside the jaw. P² (arrowed) can be clearly seen fully in the tooth row, next to the canine.

The diagram on the right, modified from Schrober & Grimmberger (1997) shows the position of P² in relation to the other teeth. For the common pipistrelle on the left (and the soprano pipistrelle), P² is tucked behind the canine rather than being fully in the tooth row as is the case for Nathusius' pipistrelle shown on the right. In some cases P² is not visible at all for the common and soprano pipistrelles.

Other features, according to Greenaway & Hutson (1990), are that the outer upper incisor (I³) nearly reaches the height of the inner incisor (I²) for Nathusius' pipistrelle. For the common pipistrelle, I³ is only about half the height of I².