From the drawers of my desk: Birds that do not fly: modifications of nature

From the drawers of my desk: Birds that do not fly: modifications of nature

From the drawers of my desk: Birds that do not fly: modifications of nature

When nature understands that we do not need something, it modifies it or eliminates it. This has been the case for birds that do not fly. According to scientists, these birds lost the ability to fly because they did not have to do so to escape predators, since in their natural habitat there were none.

What birds do not fly?

There are about 55 species of birds that do not fly, including some extinct like the dodo, the giant alca and the elephant bird, of extraordinary size. Non-flying birds are subdivided into brood birds and swimming or marine birds. In brood birds are the largest birds in the world: ostrich, cassowary, ñandú and emu. Another brood bird but smaller is the kiwi.

The penguins are a group of sea birds or swimmers. Of this group there are about 20 species found in the cold areas of the Southern Hemisphere. Another bird that does not fly is kakapo, a type of New Zealand parrot.

Modifications of non-flying birds

Birds to fly must be light, have plumage in good condition, limit their weight and size. This is not what has happened with birds that have lost the ability to fly, these birds have undergone significant modifications. Some of these modifications are: loss of the keel of the sternum (bone that holds the muscles to fly), weight gain and size, and atrophy of the wings, in addition to an increase in body fat.

The kiwi, like the kakapo, are smaller birds, which have developed a great sense of smell. This characteristic is not common in birds, but in these cases necessary for the localization of food. The kiwi has practically lost its wings, they are quite atrophied. Their feathers are so fine that they graze mammal hair. The kakapo has developed a powerful beak and very sharp nails with which he climbs the trees from where he can plan.

Another important modification is that the penguins have suffered. Its wings have evolved into rigid fins for swimming or underwater diving. Waterproof pens have shortened and become denser. They have developed a layer of subcutaneous fat that protects them from cold Antarctic waters.

Why have birds that do not fly extinct or can they become extinct? p> After birds lost their ability to fly, in a predator-free habitat, they had to deal with unforeseen predators, including humans. When the man reached the land where these birds were, carrying with them strange animals to the place, the threats to the survival of these species began. The most affected have been kiwi and kakapo, because they are the smallest ones, that have been on the verge of extinction. Another affected one is the ñandú that is hunted for its meat and for its plumage, of which they make plumeros.

As we have seen, these birds are another sign of the many contradictions that nature offers us.

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