Case of alarm vocalization in a colony of Microtus guentheri (Danford & Alston, 1880) (Mammalia, Rodentia, Arvicolidae) from Southern Bulgaria

The main frequency characteristics of alarm vocalization in Guenter’s vole Microtus guentheri (Danford & Alston, 1880), expressed by single whistle signal are presented. The alarm call was recorded in a colony of Guenter’s vole in the valley of Byala reka River in Eastern Rhodopes Mountains, Sothern Bulgaria. The start of the call is explosive and marked frequency modulated, followed by uniform frequency plateau withnarrow bandwidth of 2.3 KHz and maximum energy at 15.4 KHz.