There are approximately 20 species within six genera in the single family of Podicipedidae. While the grebes have an almost worldwide distribution–they are absent from the Arctic, Antarctica, and some of the oceanic islands.
Out of the approximately 20 species there are two that don’t fly and they are the Titicaca grebe and the Junin grebe. The Titicaca grebe has a reduced number of primary feathers (the ‘fingertip’ feathers or the wing’s outer flight feathers), and since it doesn’t migrate from its home in the highlands of Bolivia and Peru, it is listed as endangered. The Junin grebe doesn’t fly due to its inability to take off and maintain a level flight pattern. It is also listed as critically endangered, and can be found in central Peru on Lake Junin.
Since their feet are further back on their bodies than most waterbirds (though loons also have their feet further back), you will rarely see grebes walking on land. Though if you do see them walking on land–they will be walking erect and leaning thier bodies forward slightly.
One very interesting and unique trait of grebes–is that they ingest their own feathers. It is thought that the ingestion of the feathers helps to protect their digestive tracks from the indigestible parts of their prey (such as bones and shells). The feathers and indigestible remains then can be regurgitated as pellets (similar to what kingfishers and owls regurgitate).
Out of the approximately 20 species, there are seven species that can be spotted within the US, Canada, and Mexico, and they are:
Red-necked Grebe
Horned Grebe
Eared Grebe
Least Grebe
Western Grebe
Clark’s Grebe
The goals for this family are similar to the ones listed for the order–getting a picture of at least one species on each continent, getting a picture of all the species found within North America, and bonus if I get a picture of one walking erect.
Reference: www.oiseaux-birds.com/page-family-podicipedidae.html