Pheasant-tailed Jacana

BirdAsia

3 Apr

Hydrophasianus chirurgus

Pheasant-tailed jacana females are larger than the males. The species is also polyandrous — each female mates with multiple males and, in a single season, lays up to 10 clutches that are raised by different males in her harem.

Bird Breeding

It is estimated that the vast majority of birds — around 90% — are monogamous, or at least socially so.¹ This orthodox mating system entails that, at least for one mating season, a couple cooperates to raise a clutch of chicks. We see this in owls, eagles and vultures, in the numerous little songbirds and the few giant albatrosses, in graceful swans and awkward loons, in pigeons, parrots, puffins, and penguins. This exceptionally high rate of monogamy in birds, compared to other animal groups, is likely a consequence of a laborious parenting process — building a nest, incubating eggs, protecting and feeding chicks — that a single bird would struggle with on its own. In other words, most male birds can't get away with dumping the responsibility solely on a female because that would significantly lower the chances of their own offspring's survival. Only with both parents participating do most birds have a good chance of raising a healthy brood.

As with any "rule", there are exceptions. So, what about the other 10% of birds? These are the polygamous species — those that have more than one mate during a breeding season — the majority of which are polygynous; one male mating with multiple females.

A male ring-necked pheasant holds a harem of anywhere from 2 to 18 females and takes no role in incubating or raising his chicks. How does a female pheasant manage? Through diligence and dedication, yes — spending most of her day incubating the eggs, only leaving to feed in the morning and evening — but once the chicks hatch, they come out eyes open, legs marching, and are largely self-feeding (a.k.a. precocial), taking a large workload off of their mother.

Songbird moms, whose chicks hatch featherless, blind and begging for food (a.k.a. altricial), have it harder. Male red-winged blackbirds hold harems of up to 15 females within their territories. The males offer little in terms of child care. What they do offer is good real estate — good nesting sites, easy access to food and water — and protection. The males are extremely territorial, driving off potential nest predators (snakes, minks, raccoons, and other birds like crows) and brood parasites (such as brown-headed cowbirds). The females, raising nestfuls of needy chicks on their own, will at least enjoy the plenty and safety of a male's good territory.

Male parental care is still common in many polygynous territorial bird species. The "lucky" males (some 12–28%) among great reed warblers are polygynous. Again, it comes down to territory; the males with the best territory attract several females (usually 2–3) and breed with all of them. (Males with sub-par territories are either monogamous — one female, at least, gives them a chance — or fail to mate completely). As with the blackbirds, when it comes to raising chicks, a good territory is a leg up in and of itself, but a male reed warbler also helps where he can. He assists in feeding his first brood, but the more mates a male has, the less care he can provide for each brood, instead focusing on defending his territory as a whole by whistling out alarm calls if he spots danger.

Male and female ring-necked pheasants (*Phasianus colchicus*).

A male red-winged blackbird (*Agelaius phoeniceus*).

A male great reed warbler (*Acrocephalus arundinaceus*).

Polygyny is common outside of birds,² and it's common for a reason. By the very nature of gametes, or sex cells, males — with their abundant and "cheap" sperm cells — are better positioned to have many sets of children with many partners, compared to females — with their limited and "expensive" eggs — who can only have so many offspring, having to carry the heavy burdens of development as well as care. A natural outcome of this is polygyny. But it doesn't have to be. The pheasant-tailed jacana takes the expected breeding convention, and flips it on its head.

Seasonal Fashions

A pheasant-tailed jacana in breeding plumage above and in non-breeding plumage below.

The pheasant-tailed jacana is an ornate wading bird of tropical Asia, ranging from Yemen in the west to the Philippines in the east. It strides across shallow ponds, pecking up insects and molluscs along the way, stepping atop pond weeds and water lilies with its pale-blue, elongated toes and too-long, needle claws — which spread its 150 grams (~5 oz) of mass across the surfaces of floating vegetation. Even females, the larger sex, weighing up to 230 grams (half a pound), can gracefully travel these delicate, green pathways.

Both sexes are beautiful when they're trying to be. The pheasant-tailed jacana is the only species in its family to have different breeding and non-breeding plumage. Outside of breeding season, this jacana is a subdued brown, with lighter underparts, and dark streaks running down from its eyes. With the arrival of the rains, concurrent with the jacana’s breeding season, this bird becomes black along its underbelly while its head turns a pristine white. A dark line runs along either side of its neck, separating its snowy plumage from the gloriously golden feathers that adorn its nape. It also nearly doubles in length; sprouting a pair of pitch-black tail feathers, up to 38 centimetres (1.2 ft) long, that form an elegant arc from the upswept tips of its wings. Measured from beak-tip to tail-tip, the pheasant-tailed jacana is the largest member of its family. At least in its breeding plumage.

Role Reversal

During the monsoon season, pheasant-tailed jacanas couple atop floating beds of greenery, beneath a warm deluge of summer rains, both sexes bedecked in their formal breeding attires of black, brown, white, and gold. The pattering of raindrops on lily pads is accompanied by cat-like mews (“me-e-ou”) — the breeding calls of these jacanas, giving them the nickname of juana, or "cat teal", in Sri Lanka. In the Cachar district of Assam, they're known by a name that translates to "little white water princess". During their breeding season, female jacanas are, indeed, akin to royalty — but less like princesses, and more like queen regents.

The pheasant-tailed jacana is a polygamous species — like pheasants, great reed warblers, and red-winged blackbirds — but it is polyandrous; one female, many males. This unusual mating system has upset, or completely reversed, the roles that a male and female bird traditionally play. For one, it is the female who does the courting, enacting fanciful flight displays to attract as many males as she can. Many jacana females will attract a posse of three or more males, but the most alluring can accrue a harem of as many as eight, or even ten.

The jacana also defies the expected role — expected by biology — that a female plays in the rearing of offspring. She must still, of course, develop and lay the eggs (or else the sex roles would be so reversed that we'd need to relabel them), laying one every 24 hours. But she lays those eggs inside different floating nests, each constructed by one of her males. From that point on, all child-care duties are left to these single fathers.

Jacana Fathers

A male pheasant-tailed jacana caring for his clutch of eggs atop floating vegetation.

Perhaps not coincidentally, breeding success — the number of chicks that hatch and survive to maturity — is notably low among pheasant-tailed jacanas. That's not to say jacanas aren't diligent fathers. Most males do seem to try their best. It's just that their best is a little...lacking in some departments, most evidently in the reliability of their nests. These are placed atop the water, constructed from plant stalks and other pieces of aquatic vegetation with a slight depression in the centre that holds four olive-green eggs. Admittedly, some males don't bother with nests, and the eggs are simply laid on a floating leaf. Maybe these "lazy" males find that the effort isn't worth it, as even the most substantial nests can quickly disintegrate when water levels rise.

So perhaps the blame can't really be placed on the fathers; they do have to contend with a uniquely fluid nursery, an environment in constant flux. And they do try their best to rectify their nesting blunders. A male will often transport his eggs to another, drier nesting site — either by pushing the floating eggs through the water, picking them up between his bill and breast, or tucking them under his wing, and walking backwards to his newly chosen spot. But, if worse comes to worst, and the male loses his eggs, the female can lay a replacement clutch every 6 to 15 days.

Shifting water levels aren't the only danger. To predatory pond herons, brandishing spear-like bills, a jacana nest is breakfast on a floating plate. Nominally, it is the female's job to defend the many nests of her harem. She patrols her territory and performs threat displays at any intruders. She approaches them in a crouch with her wings and head up, exposing the yellow spurs on her "wrists" and the intimidating gold of her neck. If her warning isn't heeded, she rushes in, striking with both of her wings until the threat is chased off. But sometimes the female jacana isn't nearby when a hungry heron takes a stab at a nest, and the male must then step up. His defence relies less on violence, and more on deception. He performs broken-wing displays, feigning an injury, or rodent-runs, wherein he crouches and fluffs his feathers, then scuttles like a rodent to draw the predator's attention to himself and away from his brood. Once the safety of his eggs is assured, the male settles down on top of them again, the sole incubator, until they hatch in a little under a month.³

A pheasant-tailed jacana can run, swim, and dive as soon as it leaves the nest.

The chicks emerge covered in downy feathers — white and rufous with black stripes — teetering atop long legs and feet that look much too big for their tiny bodies. From the moment they take their first big steps from the nest, the chicks can run and swim and, crucially, dive. Hovering over lakes and ponds like pale phantoms are black-winged kites, their red eyes searching for vulnerable prey below. A jacana father must keep one eye on his chicks and another on the skies. If he spots danger, he gives an alarm call that commands his chicks to freeze or dive beneath the water and remain submerged, with only their beaks above the surface, until the threat passes. The chicks remain under their lone father's care for up to two months, until they're ready to lead independent lives.

Not only does the jacana go against the monogamous grain of 90% of birds, it contests the very nature of the sexes, essentially reversing the roles of male and female. Among bird mothers, it's hard to match the reproductive output of a jacana. In optimal conditions, a female pheasant-tailed jacana can produce ten clutches of four eggs each. That's 40 eggs in one breeding season — rivalling the productivity of many polygynous male birds.⁴ Ultimately, however, she must rely on the well-meaning fathers in her harem, to see that her offspring survive to adulthood.

Polyandrous Birds

Clockwise from top left; a comb-crested jacana (*Irediparra gallinacea*), lesser jacana (*Microparra capensis*), African jacana (*Actophilornis africanus*), a dunnock (*Prunella modularis*), and a red phalarope (*Phalaropus fulicarius*).

There are eight species of jacana; two in the Americas, three in Africa, and three in Australasia. All of these, except one species, are polyandrous. The exception is the smallest of them, the 15-centimetre (6-in) lesser jacana of Africa, who is staunchly monogamous. The others follow a similar system of rearing as the pheasant-tailed. The fathers of a few species — such as African jacanas and comb-crested jacanas — are even known to tuck their chicks under their wings and pick them up to transport them safely, the chicks' long-toed legs dangling from beneath the wings of their father, making him appear like some many-limbed, eldritch abomination or an AI prompt gone wrong.

Aside from the jacana family, polyandry among birds is only represented by one other group; the phalaropes. There are three species of these world-spanning shorebirds, all of which are polygynous. Females are larger and brighter, they compete for males, mating with several of them, and leaving them to incubate and raise the chicks — once a female mates with a male, she immediately abandons him to compete for another one, and, in red phalaropes, when a female is done breeding, she begins her migration south while the males are still stuck caring for the broods.

Dunnocks, unassuming songbirds from Europe, are also worth a mention. Their breeding system is, well, complicated. Depending on circumstance, they can be monogamous, polygynous (rarely, but it happens), polyandrous (one female tending a nest with two males is a common arrangement) or polygynandry (both males and females mating with multiple partners).⁵

A pair of northern fulmars (*Fulmarus glacialis*) on the top and a (thruple?) of superb fairywrens (*Malurus cyaneus*) on the bottom.

¹ The "90% monogamous" estimate comes from a 1960s study. The reality isn't as rosy as we once thought. Since that study, ornithologists have discovered — through better methods of observation and the advent of genetic testing — that infidelity is rife among birds. While the majority of species do form pair bonds during their breeding season, both males and females will sneak off to mate with individuals who aren't their partners. This is what's known as 'social monogamy', as opposed to 'sexual monogamy', where no extra-pair copulations ("affairs") occur. So most birds are socially monogamous but not sexually so.

This means that, often, many of the eggs in a bird's nest have been sired by a different male than the one caring for them. This extra-pair paternity can range from near zero in shorebirds like fulmars, where eggs in nearly all nests are sired by the male partner, to songbirds like superb fairywrens, where up to 76% of offspring in a nest were sired by other males and 95% of nests contain young sired by other males.

² Polygyny is especially prominent in mammals. Only some 3-5% of mammal species are estimated to engage in monogamous relationships, with the remaining 95% being mostly polygynous. For many mammalian species, the system is one where a male holds and protects a large territory, which he defends from other males, and that overlaps with the smaller territories of females — with which he breeds. The most obvious cases of polygyny are those in which males directly prevent other males from mating with "their" females. In other words, they have harems. A few examples include lions, gorillas and baboons, many deer species, collared peccaries, and elephant seals.

³ A male pheasant-tailed jacana typically feeds in the morning and afternoon, and sits atop his nest during the hottest part of the day.

⁴ While the female jacana may have a harem of males to do her bidding — namely caring for her young — the number of clutches a female can have is still dependent on external factors. In the African jacana, for instance, the success of a breeding season varies with rainfall. Flood years produce breeding seasons 30% longer than those during a drought year. During a flood year, more birds breed, more clutches are laid, and more chicks hatch. The pheasant-tailed jacana's African cousin is also polyandrous — at least when times are good. In a drought year, only two of five females bred with more than one male (i.e. most were monogamous), while the abundance of a flood year meant more sexual freedom, with all observed females mating with at least two males and up to seven. Tareloton, W. R. (1995)

⁵ From Cornell Lab's Birds of the World: "In a sample of 254 cases monogamy 42%, polygyny 4%, polyandry 30%, polygynandry (2–3 males with 2–3 females) 24%."

**Where Does It Live?**

⛰️ Lakes and ponds with lots of floating vegetation.
📍 Asia; from Yemen in the west to the Philippines in the east.

‘Least Concern’ as of 22 July, 2024.

IUCN

Size // Medium
Wingspan // N/A
Length // 39–58 cm (15.4–22.8 in), including a 25–35 cm (9.8–13.8 in) tail
Weight // 120–230 grams (4.2–8.1 oz)
Activity: Diurnal ☀️
Lifestyle: Solitary 👤/ Pair 👥
Lifespan: 5–7 years (in the wild)
Diet: Omnivore
Favorite Food: Insects 🦗, small crustaceans, seeds, and aquatic plants 🌾
Class: Aves
Order: Charadriiformes
Family: Jacanidae
Genus: Hydrophasianus
Species: H. chirurgus

Despite weighing up to 230 grams (half a pound), the pheasant-tailed jacana can walk atop floating vegetation with its pale-blue, elongated toes and long, needle-like claws.
This species of wading bird is found in tropical Asia, ranging from Yemen in the west to the Philippines in the east.
During their breeding season, both sexes don elaborate outfits and double their total length. Their heads turn pristine white, gold patches appear along the backs of their necks, and their tail feathers grow to lengths of up to 38 cm (1.2 ft).
The jacana’s breeding call sounds like the mewing of a cat (“me-e-ou”), earning it the nickname juana, or "cat teal," in Sri Lanka. In the Cachar district of Assam, it is known by a name that translates to "little white water princess."
Around 90% of bird species are socially monogamous, meaning one male and one female pair up — though extramarital copulations are common — and share territory, food, and the task of raising offspring. Most of the remaining birds are polygynous (one male with several females), and very few are polyandrous (one female with several males). The pheasant-tailed jacana is one of the few that is polyandrous.
This unusual mating system has reversed the traditional roles of male and female birds. For one, it is the female jacana who does the courting — usually attracting a posse of three or more males, although some females can have as many as eight or even ten.
The female still lays the eggs — one every 24 hours — but she deposits them in different floating nests, each built by one of her males. The males are then left with all parental duties.
Perhaps not coincidentally, breeding success — the number of chicks that hatch and survive to maturity — is notably low among pheasant-tailed jacanas.
The males' nests are built atop the water, although some males simply lay their eggs on a large floating leaf. Nests can break apart when water levels rise, so the fathers must often relocate their eggs — either by pushing them through the water, picking them up between their bill and breast, or tucking them under a wing and walking backwards to a newly chosen spot.
If a male loses his eggs, the female can lay a replacement clutch every 6 to 15 days. In optimal conditions, a female pheasant-tailed jacana can produce ten clutches of four eggs each. That's 40 eggs in one breeding season — rivalling the productivity of many polygynous male birds.
The eggs eventually hatch into downy-feathered chicks that wobble around on oversized legs. Awkward as they seem, they can run, swim, and dive as soon as they leave the nest.
The female takes on the job of territorial defence. She performs threat displays, approaching intruders in a crouch with her wings and head raised, exposing the yellow spurs on her "wrists" and the intimidating gold of her neck. If her warning goes unheeded, she rushes forward, striking with her wings until the threat is driven off.
Males also protect their chicks by giving alarm calls, commanding them to freeze or dive beneath the water and remain submerged — with only their beaks above the surface — until the danger has passed.