large flock of birds flying around white sand beach on coast of brown river in Rio Lagartos, aerial top down

large flock birds flying white sand beach coast brown river water rio lagartos aerial top down wildlife river mexico lagoon yucatan landscape biosphere natural reserve nature environment conservation resevoir sanctuary outdoors wilderness countryside rural estuary reserve wetland wild lake marsh sand shore beautiful tourism ecosystem habitat tropical untouched no people shallow birdwatching animals riverbank exotic sandbar