Bent-winged bats | Miniopteridae

Langvleugelvleermuizen | Murciélagos de cueva

The family is named for the wing: the outer joint of the third finger is extraordinarily long and folds back double at rest, so that the wingtip is stowed along the arm. Spread out, this gives a very long narrow wing and a fast, high flight with sharp turns, more like a swift than an ordinary bat. The fur is short, dense and velvety and the forehead strikingly high and domed. They are cave animals all year round and hang in dense clusters, touching one another, sometimes thousands strong; between the summer colony and the winter quarters they cover hundreds of kilometres, which makes them Europe's most migratory bats. Reproduction has a solution of its own: mating in autumn is followed at once by fertilisation, but the embryo's growth is halted through the winter and only resumes in spring, so that all the young are born within days of one another.