Grebes are aquatic diving birds in the order Podicipediformes. Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Most grebes fly, although some flightless species exist, most notably in stable lakes. The order contains a single family, the Podicipedidae, which includes 22 species in six extant genera.
Grebe
A diving grebe showing how the hindlimbs are propelling the bird underwater
A little grebe (Tachybaptus ruficollis) running along the surface of the water as it flaps its wings in order to get the lift it needs to fly
A skeleton of a red-necked grebe (Podiceps grisegena). Note that the pelvic girdle is bigger than the sternum.
Loons or divers are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus Gavia, family Gaviidae and order Gaviiformes.
Loon
1918 illustration of a variety of loons by Archibald Thorburn. Top: Common loon, Mid-left: red-throated loon, Mid-right: yellow-billed loon, Bottom: black-throated loon
Common loon (Gavia immer) rearing up. Note the plump body and pointed but rather short wings
Yellow-billed loon (Gavia adamsii) in winter plumage
