John Cancalosi / Gray Catbird {Dumetella carolinensis} singing, USA

John Cancalosi / Grassbird (Sphenoeacus afer) calling from flower, South Africa

Tom Vezo / Masked booby (Sula dactylatra melanops) pair mutual grooming, Tower Island, Galapagos, Ecuador

Tom Vezo / Masked booby (Sula dactylatra melanops) calling, Tower Island, Galapagos, Ecuador

DAVID TIPLING / Crested lark singing {Galerida cristata} Lesbos, Greece, Europe

Steve Knell / Wren singing {Troglodytes troglodytes} UK

Jose Luis GOMEZ de FRANCISCO / Two Common cranes (Grus grus) calling Gallocanta Lake, Spain, February

Jose Luis GOMEZ de FRANCISCO / Spotless starling (Sturnus unicolor) singing on roof top, Spain

Jose Luis GOMEZ de FRANCISCO / Common raven (Corvus corax) perching on branch, calling. Spain

Jose Luis GOMEZ de FRANCISCO / Black winged stilt (Himantopus himantopus) calling, balanced on one leg in water, Spain

Jose Luis GOMEZ de FRANCISCO / Calandra lark (Melanocorypha calandra) singing, Spain

Jose Luis GOMEZ de FRANCISCO / Hen harrier {Circus cyaneus} male in flight, calling, Spain