Handedness in the echolocating Schreiber's Long-Fingered Bat (Miniopterus schreibersii).

Bats, in terms of variety of species and their absolute numbers, are the most successful mammals on earth. The anatomical and functional peculiarities of Microchiroptera are not confined only to the auditory system; the wings (hands) of bats are unique both from an anatomical point of view as from a sensorial one. They are much thinner than those of birds and their bony structure is much more similar to a primate hand than to the forelimb of other mammals of the bat's size; the thumb, is very small and on its distal end there is a little claw that bats use for crawling and manipulating food. However, despite this very frequent use of the hands for food catching and for walking, nothing is known about the existence of a preferential use of the hands in Microchiroptera. The present study investigates the existence of handedness in the Schreiber's Long-Fingered Bat by recording the preferential use of the hand while climbing the walls of a plastic cylinder. This bat species is lateralized at population level and shows a left forelimb bias when using hands for climbing/grasping. This result is the first evidence of population-level handedness in an echolocating bat species.