Representative birds:

• Grebes

The order Podicipediformes has 1 family which is Podicipedidae, with 4 genera and 8 species. They are freshwater diving birds that inhabit wetlands such as ponds and lakes. Grebes have pointed beaks, long necks and narrow bodies which make them very skilled divers. They eat waterbugs, different kinds of fishes, snails, and shrimp

Grebe with food 

Grebe diving underwater

Morphological Characteristics

The bills of the grebes can vary in size from long and pointed or thick and short, which depends on the diet of the animal. The grebes eat fish, crustaceans, and freshwater insects. Their feet are always large and have broad lobes on the toes. Their front three toes are connected by small webs and have flat claws and their hind toe vestigial. The lobes have been shown to work like hydrofoil blades of a propeller which helps them in the water. Their toes open during the power stroke and collapse during their recover stroke. Their legs are located far back on their body making it difficult for them to walk long distances or running far on land.

Grebe feet

The plumage of the grebes is waterproof and dense. The under feathers are at right-angles to the skin which stick straight out at the beginning and curl at the tip of the feather. They can adjust their buoyancy in the water by pressing their feathers against their body. They are able to partially submerge by expelling air from their plumage which is why they normally have most of their body under water except for their neck and head. Their wings are short and rounded which makes their flight weak. Ironically, the species in Northern America are migratory birds.

Even though there has not been any recent changes to the systematics of the grebes, they were once believed to be related to the loons, which are also foot-propelled diving birds. They were classified together under the order Colymbiformes, however, in the 1930s their relationship was an example of convergent evolution by the selective forces seen by unrelated birds having the same lifestyle in different habitats and at different times. They are now in two separate orders, grebes being in the Podicipediformes order and loons being in the Gaviiformes order.

Vocalization

The first bird from this order that I listened to was the Pied-billed Grebe. The sound of the call of this grebe sounds like huk-huk-huk-huk pretty fast with a whistling sound underneath. An easy way for me to remember the call of this grebe is that to me it sounds like a toy clarinet or a recorder little kids play with. The bird looks like it is in its breeding plumage as seen in the field guide so it might be its breeding call.

The second bird from this order that I listened to was the Horned Grebe. The sound of the call from this grebe sounds like quick ah-ah-ah-ah's almost like a seagull. In the video, the Horned Grebe is in it's breeding plumage so the calls in the video are its breeding calls.

Reproduction

Pied-billed grebes use displays of their swimming ability to attract their mate. The mates may swim together, dive or rave underwater. The males also have a variety of soft cooing notes to attract its mate. They are very secretive during breeding season and are more likely to be heard than seen. During breeding, this grebe has black throat patch and ring around its pale bill.They are monogamous birds. These grebes begin breeding when they are around 1 to 2 years old. Grebes are known to be long lived birds and the pied-billed grebe is thought to live at least five years. Pied-billed grebe's clutch size range from 5 -7 eggs. Incubation usually last 23-27 days and both parents are involved with incubation. The young grebes are precocial and can swim right after hatching.

Horned grebes engage in elaborate courtship displays. During breeding they  display a more striking color scheme with a reddish chest and yellow feathery horns on the side of the head. Males and females have the same plumage, but males are slightly bigger. Horned grebes begin breeding when they are 1 year old. They have complex courtship rituals and both females and males may perform them together. An example is when the male and female run on top of the water together with their horned feathers flared out, they then dive together and then run along the water with pieces of plant in their bills. They are monogamous birds. The female horned grebe lays 4-5 eggs and both parents will help incubate the eggs for about 22-25 days. The young are precocial and can swim shortly after hatching and often ride on the parents' backs. In an article, I read that they oldest known wild grebe was at least 5 years old.

http://www.biokids.umich.edu/critters/Podiceps_auritus/