FEMALES WITH ‘HAREM’ OF MALES
Comb-crested jacana (Irediparra qallinacea) — Among the ‘harem-maintaining’ species of birds, normally, it is the male that keeps a number of females with him, but in comb-crested jacanas the role is reversed. The female not only maintains a harem, which usually has three to five males, but also takes over the traditional role of males, like defending territory and driving away predators that include avian creatures and water snakes, etc.
The female, which is larger and more brightly colored than her drab mates, spends most of her time courting males and driving away the intruding females that enter her territory in search of males. In case the female dies, then another female, normally the neighboring one, takes over the ‘harem’, destroys her predecessor’s eggs and mates with the ‘usurped’ males to pass on her genes to the next generation — lion’s parallel in avian world !!!!
Why the role of both sexes is reversed in this species? Experts believe, since predators take many of the eggs, female has to lay as many eggs as possible. To perform this function, she needs more energy for which she has to spend more time on feeding and building up energy enough to lay another clutch, if the previous one is gobbled up by the predators. In such a situation, where female spends most of the time on foraging, naturally, males will have to look after the chicks.
Acting as a ‘househusband’ or ‘stay-at-home dad’, male jacana performs all the works related with raising of a family. He builds the nest single-handedly, incubates eggs and when they hatch, he alone broods the chicks to keep them warm. Apart from feeding them, in case of danger, he provides shelter to youngsters under his wings and if threat persists, he closes his wings tightly to his sides with chicks held inside and rushes off across the lily pads, with only the dangling feet of the chicks visible. While male performs all the above functions, the female cooperates in defending the nest, eggs and chicks.
Belonging to the Family Jacanidae, jacanas have six genera with eight species found in S. Asia, Africa, Australasia, S. and C. America. They are found in rufous, greenish-brown and black colours and have a medium-length bill and broad wings. They have long legs and extremely long toes and claws.
These freshwater birds are found on the marshy shores of lakes and streams, paddy fields and freshwater margins, walking on surface vegetation and feeding on insects, aquatic animals (like frogs, small fish and molluscs) and vegetation. They nest on floating plants.
Wattled jacana (Jacana jacana) — Among birds, where females keep more than one partners simultaneously, females not only become very aggressive but also assume most of the characteristics of males. In the avian world, usually males are more colourful than the females, but here it is other way round. Normally males are larger and much stronger, but in jacanas females are larger than their mates, in other birds it is the male who courts the female here the role is reversed, even the duty of nest building, incubation and raising of chicks is performed by male.
In wattled jacanas, found in Central America, each female maintains a large territory and fiercely defends it against the other females. This area is further divided into smaller territories or sectors for her ‘harem members’, which normally include three to five males. She is free to mate with any one or all of the males and deposit her eggs in each nest that are constructed by her partners individually. Now it is the duty of males to incubate and look after the chicks, without knowing which of them is their own.
Every day female takes a round of her territory and makes sure that it has not been taken over by any intruder. In the process, she also visits each of her mates and solves their disputes that often take place between the adjacent territory holders. Whenever, there is such situation, she intervenes first from one side, then from the other.
These females have insatiable hunger for males and are always on the lookout for more. Whenever, a female dies her nest and harem (of males) is taken over by another and all the eggs and the chicks of the previous female are destroyed.
World’s longest toes and claws
Jacanas, also known as ‘lotus birds’, have the longest toes and claws in the world in relation to their body length. Their toes often span 10 cm while the body length is 17cm to 54 cm, depending upon the species. It’s very wide feet disperse its weight, so, they are able to walk and stand over the floating vegetation, such as lotus leaves or lily pads. Wherever, they find open stretch of water in their way, they simply jump over with a flick of wings. This behaviour has given them their popular name ‘lily trotter’.
In all the species, barring smaller jacana (Microparra capensis), females are larger and polyandrous, mating with more than one male.
In case of danger, some species are said to move their young from one place to another by picking up and carrying them between their wings.
Northern jacana (Jacana spinosa) — Found in Central America and the Greater Antilles, adults of the species weigh up to 175 gm, but, their feet are so big that they cover an area as large as 12.5 x 14.5cm (4.9×5.7 inches). The toes and claws of the bird are very long but the hind claw is even longer than the toe, to which it is attached.
All species of jacana have a short and blunt spur on the carpal joint or the wrist of the wings, but in northern jacana, whose females are also known for keeping a ‘harem’ of males, it is sharp and about half an inch (17mm) long.