The European Free-tailed bat (Tadarida teniotis) weighs in at 25-40g with a wingspan of up to 45cm and is Europe’s second largest bat. They roost within crevices in our limestone cliffs and caves and are fairly common in Gibraltar although rarely seen as they usually emerge from their roosts once it’s already dark and generally fly at high altitudes.
However, although difficult to see in flight, people can actually hear the echolocation calls of the European Free-tailed bat which, unlike those of all other bats in Gibraltar, peak within the audible range of most humans – in the range of 10-15 kHz. Children typically have a slightly wider audible range than adults and therefore tend to be most receptive of the ‘tsik-tsik’ chirp of this bat.
The European Free-tailed bat has charcoal-grey to silver-grey fur. About half of its tail extends beyond the tail membrane, hence its name.