Cuckoo chick evicting other eggs from the nest to ensure its own survival

It might not be fair to pick on a cuckoo, but these birds have been important to human culture for a long time in many ways. It is known as the bird that marks the start of spring in Europe because many temperate species that migrate arrive when the weather warms up after the cold winter months.

In some cultures, it’s seen as a god of desire or a sign of love that hasn’t been returned. You can also be as crazy as a cuckoo. This saying may have come from the two-note call that echoes endlessly in the wilderness Shakespeare’s or from stories of British colonists who went crazy from listening to South Asia’s loud, repetitive cuckoos, which are also called “brain-fever birds.”

Child entrapment

A second theory about how the name “cuckoo” came to be is based on the fact that 59 of the world’s 127 species of cuckoo are brood or nest parasites. This means that they lay their eggs in the nests of other birds and use their parental instincts to stay alive.

But this kind of cynicism has been called dangerous, stupid, and lazy throughout history. Some people might say that it’s a great idea to find ways to get someone else to take care of the kids.

As a “wolf in sheep’s clothing” trick to scare the host away long enough to lay eggs, a few Old-World cuckoo species have bars on the undersides of their wings and straight bills that make them look like raptors. Other species wait until the host leaves the nest, for whatever reason, and then move in to lay their own eggs.

In the battle

Several species will lay dark-colored eggs in nests with hosts that are light-colored, but only if the nest is in a very dark place or has a dome-shaped structure that blocks out light. This is just one example of how much the female has changed over time.

Some cuckoos have even learned to lay eggs that look like and are the same colour as the eggs of their chosen host. Even though many people think they look a lot bigger, the similarities between the eggs are thought to be enough to never make anyone suspicious.

Due to the hosts’ forced parenting, the birds have learned to do things like reject eggs often, which makes it more likely that the birds will reject their own eggs. Because having a successful brood is so important, some cuckoos have tried to get around this by laying more than one egg in the same nest. 

How to raise a child

But how can a bird like the reed warbler, whose babies can weigh as little as 5g and aren’t much bigger than a dime, miss this big, strange-looking animal that is at least three times its size and lives in the same nest? The parent bird has already helped the egg grow and develop by keeping it warm with the others until it looks normal.

Cuckoo chicks are usually the only ones left alive. They need their parents’ full attention, and it is rare for a cuckoo to be left alone. Fairy wrens in Australia, which call to their eggs while they’re incubating, are a good example of a way to fight back against this cruel method. When the eggs hatch, any chick that doesn’t give the “password” is kicked out if the rest of the chicks can’t or won’t do the same thing. Research shows that cuckoo chicks are always the ones to be kicked out.