Why do Sparrows hop or Why 'Koel' sings only in the spring?

Birds play an important role in our day to day life. Is Science involved in their behaviour?
'Koel' sings only in the spring. Why?
The pleasant ku-hu notes of koel, we hear only in the spring. We believe in general that the female koel emit these sweet notes which is wrong. It is the male koel that produces these notes.
The male and female koels look differently. The female koel's body is ash coloured with white spots where as the male is black in colour, just like a crow. The female koel is not capable of emitting melodious notes.

Koels mate during spring season and lay eggs to increase their population. The male koel produces the pleasant ku-hu notes to attract the female koel in this season only. Once the spring season is over the male koel does not sing. That is the reason why we hear the singing of koel only during spring.

The female koel lay eggs but it cannot hatch them. So the female koel lays her eggs in a crow's nest and crow carries the process of hatching. Usually crows live very close to the human habitation and build their nests on the trees. So the koels migrate nearer to the villages and cities during summer and after the mating season is over, lay their eggs in crows nests and fly away towards thick forests.

Why do sparrows hop?
Most of the birds walk on the ground just as we walk moving one foot forward and then moving the other foot, left, right, left, ....... When birds like crow, parrot, hen walk in this way, the sparrow does not like this style of walking. It chooses 'to hop' on both the feet.

The reason for the sparrow to hop instead of walking is, it is easier and comfortable for it to do so. The legs of a sparrow are very short compared to its size and the bones at its knees are stiff and cannot be bent easily. Moreover, these short and stiff legs are not located in the middle of the body (centre of gravity) and are situated little towards the back. If a sparrow likes to walk like us, it has to lift one of its foot and then the other foot would not be able to support the entire weight of its body and it falls. But instead of walking putting forward one feet after the other, if a sparrow hops, it can balance itself on both its feet without falling. So unlike other birds walk left, right, left... a sparrow moves on the ground Hop, Hop, hop, .....

Lakshmi Emani

Published date : 06 Jul 2012 01:42PM