flock of adult laughing gull birds in flight over the biebrza river wetlands in poland in early spring nesting period

laughing gull larus ridibundus mewa smieszka bird poland polska biebrzanski biebrza sky blue flight spring lake park color colorful travel tourism outdoor nature animal avian wing wings living wildlife wild wetland wetlands moor marsh marshes swamp swamps natural conservation bill beak tail group few many pack flock adult birds over river early nesting period