Polyandry & male participation during chick rearing age
Polyandry, a mating system where parental duties are role reversed (male incubates and rears the chicks), is very rare amongst the world’s bird species, and makes up less than one percent of the breeding species in South Africa. In this mating system, females take up territory and mate with multiple males that are then left with all parental duties!
Below: The following 4 species, Black Coucal Centropus grillii, African Jacana Actophilornis africanus, Greater Painted-snipe Rostratula benghalensis and Common Buttonquail Turnix sylvaticus, are all sequentially polyandrous breeders in South Africa.
Additionally, the other two buttonquail found in the region, are also polyandrous, and so too is Striped Crake Aenigmatolimnas marginalis. Interestingly, none of the other Coucals in Africa, nor Lesser Jacana Microparra capensis, are polyandrous breeding species. Pale Chanting Goshawk also sometimes form polyandrous trios, with one female mating with more than one male in the same territory. More commonly, however, they breed in pairs.
In all the above species, males participating in this unique breeding system, incubate alone and care for the young without any help from the females.
Within this small select group, only Black Coucal rears altricial young (born blind, featherless and mostly immobile). All other polyandrous breeders in the region rear precocial young that are able to walk, run, and to some extent feed themselves soon after hatching, which means that Black Coucal male carries the additional burden of single-handedly having to provision the offspring with food and leave them unattended in the nest for much of the day while he is away hunting to food. Because of this, the chicks are for the most part silent and do not solicit loudly for food from within the nest while the male is away hunting in the nearby lowland grassland.
Below: A typical Black Coucal nest placed between grass tufts about 15 – 20 cm above the ground.
Below: A one day old Black Coucal (top left), a 13day old nestling about to fledge (bottom left), and the adult male provisioning the chicks with food.
Below: This 13 – 14 day old Black Coucal chick exited the nest the following morning after it had been ringed. They are able to catch invertebrate prey and survive on their own from about this age, as they are only fed for the first day after leaving the nest, long before they are able to fly! Remarkable birds!
The combined incubation and nestling period for Black Coucals is less than a month, so, in spite of them being migratory, they are still able to produce up to three broods between November and March!
Using African Jacana as an example, the following set of images illustrates the attentiveness and round-the-clock care given by polyandrous males rearing precocial young (chicks that hatch with downy feathering, open eyes and are able to walk or even run!). Precocial chicks follow the males and leave the nest site within hours of hatching.
Below: A quick glance at this rear view of this adult male Jacana, may leave you wondering about the two protrusions on its back.
Below: Two of the three inquisitive chicks take a look at the surroundings!
Below: Their long legs enable them to stand in the shallow water!
Below: The three chicks abandon the security of the adult, and run off in the shallow water in search of food.
Below: A chick on a mission …………. food!
So, of the 7 polyandrous breeding species in South Africa, Black Coucal stands out as the only one that rears altricial chicks, and with it, the additional burden of brooding featherless young, and feeding offspring until the day after they have fledged!
Chick ‘abandonment’ by male Black Coucals one day after they leave the nest, is truly remarkable, especially when you compare the attentive nature of the other polyandrous males in this select small group of unusual breeding birds.
Huge Chittenden
