Jacanidae Jacanas
Version: 1.0 — Published March 4, 2020
Introduction
Jacanas are the water-striders of the bird world. Though they cannot walk on water, their exceedingly long slender toes, extended by long splint-like nails, allow them to walk on very flimsy floating vegetation. Far more vocal than their near relatives, they spend much of their time far from cover, flying readily whenever danger threatens. As in many families in this order, their polyandrous mating system leaves the males doing all the parental care. The precocial young are capable of feeding themselves from the start, so the father is left watching over them and offering his wings for shelter if danger arrives. With such a precious cargo beneath his wings, he cannot fly away, but parental discretion and anticipation usually allow him to deliver his brood on foot to safety.
Habitat
Jacanas live in a variety of shallow freshwater wetlands with emergent or floating vegetation.
Diet and Foraging
Jacanas eat mostly insects, mollusks, and crustaceans; in some species at some times, seeds (mostly of water lily) may constitute 20% to 50% of the diet.
Breeding
The smallest jacana (Microparra) appears to be monogamous with biparental care, but all other jacanas appear to be sequentially polyandrous, where a female mates with a male, lays a clutch of eggs for that male to care for, and then moves to another mate. A complete clutch is typically 4 eggs. Within a population of jacanas, not all females are polyandrous, and many ultimately pair with only one male. Genetic data have shown that a clutch of eggs cared for by a particular male is most often exclusively sired by that male. Jacana nests consist of fairly sparse floating mats of vegetation, usually built over shallow water. In some nests, the eggs are in contact with the water, as the nest platform does not rise above the water level, and males spread their wings down and under the eggs, two per wing, to support the eggs against the male’s body while he incubates. Females may help with the initial stages of nest construction, but the males conduct the majority of nest-building and are generally solely responsible for incubation, brooding, and caring for the chicks. Incubation takes about a month, and males often provide the young shelter under their wings when danger threatens. Under threat, chicks may also “snorkel,” whereby they completely submerge themselves in the water, with only their bills above the surface to breathe.
Conservation Status
While all species of jacanas have likely declined as a result of habitat loss and degradation, one species (12%), the Madagascar Jacana Actophilornis albinucha, has declined significantly in recent years from continued hunting pressure and habitat loss (1 NT).
Systematics History
Jacanidae is part of the suborder Scolopaci of Charadriiformes, where it is sister to Rostratulidae, a relationship that is supported by both morphological characters and molecular data (Cracraft 1981, Sibley & Ahlquist 1990, Paton & Baker 2006, Baker et al. 2007a, Fain & Houde 2007, Livezey & Zusi 2007, Gibson & Baker 2012).
Conservation Status
Least Concern |
87.5%
|
---|---|
Near Threatened |
0%
|
Vulnerable |
0%
|
Endangered |
12.5%
|
Critically Endangered |
0%
|
Extinct in the Wild |
0%
|
Extinct |
0%
|
Not Evaluated |
0%
|
Data Deficient |
0%
|
Unknown |
0%
|
Data provided by IUCN (2023) Red List. More information