black-necked grebe or eared grebe (Podiceps nigricollis) Toledo, Spain
They get their name from their dark black necks and breeding plumage, which features ochre-colored feathers around the ears and ear coverts.
Close view of an eared grebe, seen in a North California marsh
Eared grebes are the most abundant grebes in the world and often flock or nest in large numbers that can number in the thousands.
Eared Grebe in Saskatchewan Canada Pond with eggs
Eared grebes engage in brood parasitism, with nearly 40% of nests containing eggs from more than one female.