Comb-crested Jacana
The Comb-crested jacana (Irediparra gallinacea), frequently referred to as the lotusbird or lilytrotter, is a highly specialized bird adapted for life atop the floating vegetation of tropical freshwater wetlands. As the sole species within the genus Irediparra, this bird is a master of its unique environment, utilizing extraordinary physical adaptations to navigate surfaces that would sink most other avian species.
Key Facts
- Scientific Name: Irediparra gallinacea
- Conservation Status: Least Concern (IUCN 3.1)
- Distinctive Feature: A fleshy red wattle (comb) on the forehead and forecrown.
- Mating System: Polyandrous (one female mates with multiple males).
- Primary Habitat: Freshwater swamps and lakes with floating mats of vegetation.
- Diet: Aquatic insects and seeds.
Physical Description
The comb-crested jacana is visually striking and easily identified. Its most prominent feature is a fleshy red wattle covering the forehead and forecrown, which contrasts sharply with a white face and throat. This comb shifts in color based on the breeding cycle, appearing pinker in breeding adults and more orange during non-breeding periods. The bird possesses a black crown and hindneck, a white belly, and a broad black band across the lower breast.
Its plumage is primarily grey-brown on the back and upperwings, while the rump, tail, and primary coverts are black. When in flight, the black underwing and flight feathers become most visible. One of the most critical adaptations for its lifestyle is its long legs and extremely long toes, which distribute the bird's weight, allowing it to walk on floating plants. These long toes are clearly visible trailing behind the bird during flight.
There is a notable difference in size between the sexes. Females are larger, measuring 24–27 cm (9.4–10.6 in) in length and weighing 120–150 g (4.2–5.3 oz). Males are slightly smaller, measuring 20–22 cm (7.9–8.7 in) and weighing 68–84 g (2.4–3.0 oz). The wingspan for the species ranges from 39 to 46 cm (15 to 18 in).
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Distribution and Habitat
This species is found across a wide range of tropical regions, including south-eastern Borneo, the southern Philippines, Sulawesi, the Moluccas, and the Lesser Sunda Islands. It also inhabits north and south-east New Guinea, New Britain (specifically Lake Lalili), and northern and eastern Australia.
The comb-crested jacana resides in large freshwater wetlands, lakes, and swamps. It specifically requires habitats with abundant floating vegetation, such as water hyacinth or water-lilies, which form a dense mat on the water's surface. While the species is considered rare and localized in certain areas, it is not globally threatened.
Behavior and Ecology
General Behavior
The comb-crested jacana is characterized by a slow, deliberate walking style. These birds often congregate in flocks. When they feel threatened or disturbed, they typically fly low over the water before landing again on open vegetation.
Feeding and Vocalization
The diet of the comb-crested jacana consists mainly of seeds and aquatic insects, which it gleans from the surface of floating vegetation. Its voice is distinct, consisting of a high-pitched, squeaky chittering or a shrill trill that may include an explosive soft bugle sound.
Breeding and Reproduction
The species practices polyandry, a mating system where one female mates with several males. The female constructs a flimsy nest on emergent or floating vegetation and lays four lustrous, pale brown eggs marked with black. In a reversal of typical avian roles, only the males incubate the eggs. The chicks are well-developed upon hatching and leave the nest shortly thereafter.
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Species Summary
| Feature | Male | Female |
|---|---|---|
| Length | 20–22 cm | 24–27 cm |
| Weight | 68–84 g | 120–150 g |
| Role in Breeding | Incubates eggs | Lays eggs |
| Wingspan | 39–46 cm |
Frequently Asked Questions
What makes the comb-crested jacana unique among birds?
It is unique for its extreme adaptation to floating vegetation, its distinct red facial wattle, and its polyandrous mating system where the male is the primary caregiver for the eggs.
Where can the comb-crested jacana be found?
They are distributed across south-eastern Borneo, the southern Philippines, Sulawesi, the Moluccas, Lesser Sunda Islands, New Guinea, New Britain, and northern and eastern Australia.
What do comb-crested jacanas eat?
They primarily feed on aquatic insects and seeds that they find on the surface of floating wetland plants.
Is the comb-crested jacana an endangered species?
No, according to the IUCN 3.1 classification, the species is listed as Least Concern, although it can be rare and localized in some regions.
How does the bird walk on water?
The bird does not walk on water itself, but rather on mats of floating vegetation. Its extremely long toes distribute its weight across a larger surface area, preventing it from sinking into the plants.