It is found in the Mediterranean region and Balkan peninsula, as well as parts of Italy.

The wingspan of R. euryale is between 30 and 32 centimetres (12 and 13 in), with a standard weight between 8 and 17.5 grams (0.28 and 0.62 oz).

Mating takes place in the Autumn in caves, but may continue in the winter roosts.

[4] The general population decline is attributed to the increase in agriculture and urbanization causing the loss of vegetation R. euryale uses to forage for insects.

Protecting their roosting sites is considered an important long term conservation strategy.