Sadly, in about a couple of percent of the world’s bird population, the males do not mate solely with one female. This is called polygyny.
In Humans, Polygyny is a marriage in which two or more women share a single husband. This concept of polygyny was exclusive in mammals until recently. However, researchers have now come across 2% of the bird population that practices this theory.
Polyandry, having one female mate with numerous males, is followed by less than one percent of the entire bird population.
In the polygyny system, males mate with multiple females but provide little or no care for their young. There are two kinds of polygynous males, those that defend females and those that defend territory.
In the latter case, which the red-winged blackbird of North America practices, the male carves out a territory that provides numerous classy nesting sites and food. He guards the colony against other males (potential threats in the red-winged blackbird population) and makes remarkable displays to attract females. The female red-winged blackbirds stop by, and if they enjoy his displays and love the territory, then they will quickly mate with him and build a cozy nest in his region. The male presents virtually no help to the females. He may support a little with the first female that mates with him or with nestlings that hatch late during the breeding season when mating possibilities wind down.
In South and Central America’s tropical forests, the oropendola guards a stable of females to stop other males from ever mating with them. A fundamental behavior is that these birds nest in large colonies. Boat-tailed grackles of North America are also polygynous of the second variety.
In the concept of polyandry, a female mates with a male, then lays eggs inside the nest, and after that, she randomly leaves the dad to care for them while she pairs up with yet another male. In the jacana case, found in Central America, southern Mexico, and the southern section of West Indies, the female jacana partners, and mates with various males at a time. The males build the nests, raise the young, and incubate them while the female defends against other females. In the brown skua’s case, another polyandrous subspecies, the female mates with many males but lays all her eggs in a single nest. She also plays a role in helping with egg-incubation and properly raising the young.
The female birds protecting the colony, while the male helps with the child concept, is one of the significant evidence of equality in the bird population where roles are reversed in the particular species we explored above.