Non-invasive acoustic detection of wolves

(). Non-invasive acoustic detection of wolves. Bioacoustics, 26 Peer reviewed.

Monitoring wolves (Canis lupus) is a difficult and often expensive task

due to high mobility, pack dynamic, shyness and nocturnal activity

of this species. Wolves communicate acoustically through howling,

within pack and with packs of the neighbourhood. A wolf howl is

a low-frequency vocalization that can be transmitted over long

distances and thus it can be used for monitoring. Elicited howling

survey is a current method to monitor wolves in different areas all over

the world. Elicited howling, however, may be invasive to residential

wolf packs and could create possible negative reactions from the

human population. Here we show that it is possible to detect wolves

by recording spontaneous howling events. We measured the sound

pressure level of wolf howls by captive individuals and we further

found that elicited howling may be recorded and clearly identified up

to a distance of 3 km. We finally conducted a non-invasive acoustic

detection of wolves in a free-ranging population. The use of passive

sound recorders may provide a powerful non-invasive tool for future

wolf monitoring and could help to establish sustainable management

plans for this species.