It is a familiar scene in real life and in movies. In a group of 100 excited lambs, an ewe, or female sheep, has no problems picking out her lamb. She does this through the sense of smell.
More than one million animal species live on our planet and the females of the species recognise their young ones through smell, sound, sight or touch.
Actually, most mammals recognise their young ones by smell. As soon as it gives birth, one of the first things a mare, ewe, doe or seal does is to smell the newborn. It becomes a mark of recognition. And, that is important for mammals, for, they take care of their young ones till such time as they are able to take care of themselves. Watch any movie about animals and you will see a cow or a mare sniffing at its calf or foal.
Birds, however, are different. They recognise their infants through their voices. The mother makes a special ‘mother call’, which the baby takes note of as soon as it hatches out of an egg.
A scientist called K. Lorenz once conducted an interesting experiment on geese. He removed the mother goose to another place just before the eggs hatched. Then he imitated a ‘mother call’. The result was that the goose lings followed him everywhere. They got a bit confused when they saw him standing, but they were absolutely comfortable with him as long as he stayed on his knees and crawled before them!