Sungrebes: Heliornithidae

Sungrebes may be solitary, that is, may live by themselves, or are found in pairs, generally male and female breeding partners, or family groups. Sungrebes are permanently territorial, meaning they defend their territories from other individuals of the same species during the breeding season as well as the nonbreeding season. Sungrebes are shy birds rarely seen by people. They usually swim close to cover and may hide either in vegetation or in the water, with their bodies underwater and their heads lowered, when they are disturbed. They are good swimmers but also capable walkers and climbers. Sungrebes tend to roost, or spend the night, in trees or bushes.

Although all three subgrebe species have distinctive calls, these are not often heard. The African finfoot makes a loud booming sound during breeding. The masked finfoot has a bubbling call. The sungrebe has a "eeyoo" call that it makes to warn other sungrebes away from its territory.

Sungrebes breed when water levels are high. All three species are monogamous (muh-NAH-guh-mus), meaning a single male breeds with a single female. Courtship rituals, which are characteristic behaviors individuals perform before mating, vary among the species. In the African finfoot, one individual raises and opens its wings while the other individual remains under cover and responds with a snapping noise. In sungrebes, potential mates swim in circles towards each other, raising their wings and lowering their heads in a characteristic manner. Both males and females participate in building the nest, which is generally a shallow bowl of sticks lined with dead leaves. Nests are generally built in areas of thick vegetation about 3 feet (1 meter) over water, often on top of debris that remains caught in branches. Usually, two to three eggs are laid at a time, and both parents incubate, or sit on, the eggs. Eggs hatch after ten to eleven days.

In the sungrebe, chicks are altricial (al-TRISH-uhl), that is, they hatch naked, without feathers, blind, and unable to move. Males carry the chicks in pockets of skin under the wings until they are better able to fend for themselves. In the African finfoot and the masked finfoot, the chicks are semi-precocial (semi-pree-KOH-shul), a state between altricial and precocial, fully developed. Although they cannot leave the nest immediately, as fully precocial chicks can, they generally leave the nest after a few days.