ideo Byte: Jacana
Class: Aves (Birds)
Length: males—6 to 15 inches (15 to 39 centimeters); females—6 to 23 inches (15 to 58 centimeters)
Weight: males—1.4 to 4.8 ounces (41 to 137 grams); females—1.4 to 9 ounces (41 to 261 grams)
Life span: unknown
Number of eggs laid: 4 eggs
Incubation: 20 to 26 days
Age of maturity: 1 year
Status in the wild: Stable
When spread out, a jacana’s
toes and claws can cover an area up to 5 by 8 inches
(12 by 20 centimeters).
• Pheasant-tailed and northern jacana males will pick up the empty shell of their newly hatched chick and fly several yards (meters) away before dropping it. This may keep predators away from the nest.
• Female jacanas can be almost twice as big as the males.
Jacanas are colorful birds with long legs and incredibly long toes and claws. The super-long toes spread the bird’s weight over a large area. This allows them to walk across floating vegetation, especially lily pads. Jacanas often appear to be walking on the water itself! They are also very good swimmers and divers, and they can swim through open water from one area of vegetation to another while searching for food or to avoid danger.
At home on the pad
Lily pads and other floating vegetation in swamps and marshes are home to jacanas. They live out much of their lives on these floating islands, foraging for fish and insects to eat and building their nests. Jacanas are carnivores that use their bills to turn over lily pads or other aquatic vegetation. They can also grasp the edges of these plants with their toes to partially turn them over in search of food. These waterbirds often send out noisy alarms when they think predators are near.
If threatened, young chicks, as well as adults, stay underwater for long periods of time with only the tips of their bills above water. They can also swim underwater to avoid predators. It is not known what types of animals prey on jacanas, as predation has not actually been observed. Researchers believe that jacana predators may be other birds, as well as fish or other aquatic life. Jacanas are weak fliers and usually only fly for short distances. Some species, such as the African jacana Actophilornis africanus, molt all of their wing feathers at the same time and are unable to fly until their new feathers grow in.
Some jacana species, such as the northern jacana Jacana spinosa and the wattled jacana Jacana jacana, have chestnut- to cinnamon-colored bodies, with yellow to greenish yellow flight feathers, dark brown to black neck and head, and a yellow bill. The African jacana also has a chestnut body, but its neck and head are white in front and black in back, with a golden yellow breast. The Madagascar jacana Actophilornis albinucha has the same colors as the African jacana, but with the neck and head colors exactly reversed. There is even a pheasant-tailed jacana Hydrophasianus chirurgus with (what else!) a long tail like a pheasant. Most jacana species also have what is called a frontal shield, which is a bare, fleshy area that extends from the bill to as far as the top of the head. Most of these shields are red, but the African and Madagascar jacanas have a bright blue shield. It is thought that the blue color reflects light, or that it allows the bird to blend in with the water, allowing it to escape being seen by predators.
Jacana eggs are true works of art. They are a deep tan color, with very dark markings that look like dribbled lines of paint, crisscrossing the entire egg in an abstract design that is different on each egg. The eggs are very glossy and shiny and look as though they have been highly polished. This “wet” appearance is nature’s camouflage, helping the eggs resemble the glossy surface of surrounding vegetation.
Male jacanas do most of the nest building. After the female has laid a clutch of four eggs, the male takes over the parenting responsibilities. He incubates the eggs and protects them from danger. Jacana nests are built on mostly submerged plants. If the nest starts to sink, or the eggs are otherwise endangered, the male may pick them up and carry them under his wings to a new site. Meanwhile, the female has left the male to find more males to breed with. She does not participate in raising chicks. If, however, the eggs or chicks are lost, she will return to breed and produce a replacement clutch with the first male. Only one species, the lesser jacana Microparra capensis, is known to be monogamous.
Jacana chicks are precocial, so the male quickly teaches them how to forage for the insects, snails, worms, small crabs, fish, mollusks, and seeds that make up their diet. Jacana species at the San Diego Zoo Safari Park are fed mealworm larvae, crickets, a special zoo carnivore food, and commercial flamingo food. Chicks stay with the male for their first 40 to 70 days. The father will even carry his young chicks under his wings if they are in danger.