Great Blue Heron Walking In Flowing Water At Blackwater National Wildlife Refuge In Maryland, USA

heron bird great blue heron blue heron walking flowing water blackwater refuge maryland usa lake birdwatching river birding estuary behavior habitat fauna wildlife refuge us nature outdoor beak wading animal environment wildlife wing reflection closeup national feather ardea herodias migratory hunter coastal natural wild portrait pond predator wetland america blackwater national wildlife refuge behaviour marsh swamp shore bird