a flock of black-headed gulls (chroicocephalus ridibundus) in winter plumage flies low above the danube in belgrade

seagull black headed gull chroicocephalus ridibundus animal balkan bird dusk europe famous feathers landmark landscape migratory nature gulls blackheaded winter plumage flock birds danube belgrade beograd water flight reflection river aquatic graceful wings wildlife serbia serbian srbija overcast peaceful floating avian urban environment flying group calm scenic natural habitat gathering