two cheerful black headed gulls performing mating rituals

animal april avian baltic bird birdie black blackheaded chase cheerful chroicocephalus colonisation couple dipping display drops espoo european evening feather finland finnish flight frolicking game gull gulls head headed joy jumping laughing marsh mating migratory mouth move movement nature ocean ornithology outdoors performing play reeds reflection ridibundus ripple rites ritual rituals romp scandinavia sea seabird seagull seagulls shorebird speed splash spray spring squawk squawking suomi take two water waterfowl wetlands wildlife wing