New Zealand’s walking bats

New Zealand’s lesser short-tailed bat Mystacina tuberculata is slightly odd in the bat world due to its propensity for running about on the ground instead of flying.  Unlike most bats, which catch their prey while in flight, the lesser short-tailed bat spends much of its time foraging on the forest floor.  The elbow joints in their wings are specially adapted to function as front limbs enabling them to move with rodent-like agility. 

Up until now the prevailing view has been that evolution of terrestrial locomotion in our bats was the result of our long period of isolation and lack of mammalian predators – much the same reasons why flightlessness evolved in many of our native birds. However a new study published in BMC Evolutionary Biology has challenged this hypothesis by comparing the anatomy of the short-tailed bat with the fossil remains of a related extinct species from Australia.  This study suggests that terrestrial locomotion evolved in this family of bats before their arrival in New Zealand, and in the presence of mammalian predators.