Attractive birds of the tropics of Asia, Africa, South America, and Australia, Jacanas sprightly move over the tops of lily pads and other floating vegetation with ease. They are weak fliers and go aerial for only short distances, but they can swim underwater to avoid predators and remain in the water for long periods with only their bill above the surface, All eight species are attractive, having a dark body with a contrasting breast and/or head and neck, but the most obvious characteristic is their elongated toes and claws that allow them to walk on emergent and floating vegetation, giving them the sometimes moniker of “Jesus bird.” They are also called the lotus bird or lily trotter. Jacanas usually have a brightly colored patch of bare skin, called a frontal shield, in front of their eyes and above the beak that may serve a purpose in sexual selection or territoriality. Most of these shields are red, although the African and Madagascar jacanas have a bright blue shield.
Jacanas are mostly carnivorous, eating insects, fish, snails, worms, and small crabs by grabbing lily pads with their beak and turning them over. They will eat seeds and plant roots but tend not to eat plants except in the process of snatching animal prey. The Wattled Jacana of South America will also pick parasites off the back of a capybara.
Like many shorebirds, jacanas lay four eggs, the male alone building a nest built of floating and emergent plants. Besides nest construction, in most species, the male also incubates the eggs and cares for the young birds. Since the nest is at least partially floating, the eggs are in danger of getting wet and cooling, so the male jacana incubates the eggs under his wings, next to his body. “This wing-brooding may be assisted by a special adaptation in the wing bones with either a broadening of the radius or a widening of the gap between the radius and ulna. Young chicks may also be held under the wing and transported to safety by the parent bird in some species.” Wikipedia
Most species of jacanas are polyandrous, meaning that a single female will mate with several males and then lay eggs in each of their nests. Typically, a female will mate with two to four males, although the number can be as many as 10 in the case of the Pheasant-tailed Jacana. The female defends the territories of the males while incubation is occurring but abandons the nest and territory once the young hatch. The females are larger than the males but the plumage of both sexes is similar. (Only the Lesser Jacana is monogamous but the male still does most of the work.)
The Jacanidae is a family in the Order Charadriiformes which contains shorebirds, auks, and gulls and terns. Less than one percent of all birds are polyandrous, and most of them belong to this order, such as the phalaropes, stints, plovers, and Spotted Sandpiper, as well as the jacanas.
The name jacana comes from Brazilian Portuguese via the native Tupian language word jasaná.