Wild Wonders of Europe / Benvie / Alpine marmot (Marmota marmota) giving an alarm call, Guillestre, Queyras, France, June 2009

Terry Whittaker / 2020VISION / Pine marten (Martes martes) 4-5 month kit taking refuge in tree in caledonian forest after alarm call from adult female, The Black Isle, Highlands, Scotland, UK, July

Terry Whittaker / 2020VISION / Pine marten (Martes martes) 4-5 month kit taking refuge in tree in caledonian forest after alarm call from adult female, The Black Isle, Highlands, Scotland, UK, July

Terry Whittaker / 2020VISION / Pine marten (Martes martes) 4-5 month kit taking refuge in tree in caledonian forest after alarm call from adult female, The Black Isle, Highlands, Scotland, UK, July

Terry Whittaker / 2020VISION / Pine marten (Martes martes) 4-5 month kit taking refuge in tree in caledonian forest after alarm call from adult female, The Black Isle, Highlands, Scotland, UK, July

Markus Varesvuo / Redshank (Tringa totanus) making alarm call, Norway, June

Gerrit Vyn / Surfbird (Aphriza virgata) in breeding plumage on its alpine breeding grounds. Bird is giving its alarm call. Seward Peninsula, Alaska, USA, June.

Gerrit Vyn / Adult male Black-bellied / Grey Plover (Pluvialis squatarola) giving an alarm call. Seward Peninsula, Alaska, USA, June.

Steve Knell / Redshank (Tringa totanus) giving alarm call to young from post. Outer Hebrides, Scotland, UK, May 2007

Dave Bevan / Great tit {Parus major} on branch sounding alarm call, Carmarthenshire, Wales, UK

John Cancalosi / Richardson's ground squirrel giving alarm call {Spermophilis richardsonii}

Bernard Castelein / Southern plains grey / Hanuman langur {Semnopithecus dussumieri} making alarm call, Sariska NP, Rajasthan, India