A Glimpse of Bird Behaviour - Breeding of birds

With birds, breeding is not just about copulation and procreation. We can even draw several parallels from courtship and tokens of affection.

With birds, breeding is not just about copulation and procreation. It involves a complex process, like with humans. We can even draw several parallels, from courtship and tokens of affection (eggshell, pebble, flower petal, food) to building a home together, raising a family, and even fidelity, infidelity, and divorce.

Some birds are monogamous while some are polygamous.

•   Courtship

Courtship is sometimes a very subtle affair, with the only sign being two birds spending all their time together. Sometimes, it involves very flamboyant and elaborate rituals, involving courtship dances, songs, and more.

In certain species of birds, the males have a more colourful plumage than the females. For example, the male sunbirds have brightly coloured plumage, in shades of blue, purple, orange, etc., according to the species, while the female sunbirds are of a dull brown colour. Among the magpie robins the males are deep black and white in colour, while the females are dark grey/ dull black and white. Even among the peacocks, the male peacocks are the ones with a long, colourful tail feathers. It is seen that this difference in plumage colour of such bird species play a huge role in  their courtship. The females choosing the more brightly coloured males might be related to Darwin’s principle of ‘survival of the fittest’, as they believe that only the male birds which are healthy can afford vibrantly collared plumage. While talking about colours, it is interesting to note that the iridescent colours, like the shining blue or purple or black, in some birds (like the glossy ibis, sunbird, etc.) are created not because of pigments, but because of the way light is reflected by the elaborate arrangement of the fibres in the feathers.

As an example, for mating rituals, we can consider the dance of the peacock. The male peacock spreads its tail feathers in an arc and dances to attract the females, and it is said that female birds prefer male birds with the most number of ‘eyes’ on their tail feathers.

Among some birds, while their plumage isn’t vividly coloured, there is still some difference in the plumage during the breeding season and non-breeding seasons. A good example is the egret or pond heron. The breeding plumage of the egret is a bit more showy, with fine long feathers from the rear crown, and feathers along the upper breast, called the ‘aigrette’.

A male magpie-robin ©Bhavana

•   Nest building

Nests vary in size, shape, texture, material used, and location. Some birds reuse their nests, while others build a new nest during each breeding season.

In most species of birds, the females build the nest, while in some both males and females build the nest together. In some species, the males build the nest, and this plays a role in the courtship as well. The weaverbird is a good example for this. Birds like the cuckoo, on the other hand, do not bother with nests, as they lay their eggs in the nests of other birds, in a parasitic manner.

It is not the type of nest, and the act of building the nest that differs. Different species of birds exhibit different behaviours during the time of nest building. For example, if we take the purple-rumped sunbird, the female bird builds the nest on its own. But the male bird always watches over it, guarding it from other male birds. The male birds can be seen flying alongside the female bird while searching for building materials. In search of materials like cobwebs, these birds can be seen closer to buildings during this time than during other times of the year.

A female purple-rumped sunbird building a nest. Although the interior of the nest is lined with smooth materials, note that the exterior is studded with rough fibres and leaves. ©Bhavana

A male purple-rumped sunbird watching over its female building a nest  ©Bhavana

•   Mating & incubation of eggs

The mating behaviour begins as the nest building finishes. It doesn’t last for long though. It occurs only for a few days, until the eggs have been fertilised. This is why it is easy to miss the mating behaviour than the other b behaviours.

Once mating is over, the female bird lays the eggs in the nest. Birds like the cuckoo lay their eggs in another bird’s nest, and leave them to be incubated by those birds. Usually, the females incubate the eggs. But in some species, such as the rock pigeons, both the male and female birds take turn incubating the eggs. In polyandrous bird species, the female can lay more than one clutch (i.e., a group of eggs fertilised at the same time, and incubated together). So, the males have to incubate the eggs in some nests, while the female incubates in one nest.

Birds like the penguins do not need nests to incubate the eggs. Penguins lay one egg at a time, which is incubated by keep it one top of the penguin’s feet. The male and female penguins take turns incubating the eggs. The exception is the Emperor penguins - male Emperor penguins take full responsibility of incubation.

•   Rearing chicks

Birds that have incubated their eggs will care for the chicks once they have hatched. Many studies have shown that there is a considerable equality among male and female birds when it comes to taking care of their offspring. This is particularly more so among monogamous birds. The role played by the female and male birds differ according to the species of birds.

In some species (such as the purple-rumped sunbirds), even birds of the previous brood help in feeding their younger siblings.

 

Greater flamingos: a pair of fully adult birds (brightly coloured)
and subadult birds (dull coloured). ©Bhavana

 Click here to read about the Locomotion of birds

 Click here to read about vocalisations of birds

 Click here to read about feeding behaviour of birds. 

Click here to read about Fascinating flight of birds

The next article will explore the vocalisation behaviours of birds.