There are many birds that cannot fly. When we talk about birds, the ability to fly comes in our mind. We think of the height up to which the birds can fly. Many birds migrate during winter by flying for thousands of kilometers. But there are also many beautiful birds that are flightless due to some reason or the other.
These birds develop other warps to get around and do not need wings. In areas such as New Zealand, South America where birds find food easily and have no natural predators, they do not need to migrate for protection and food. Also, the wings of the flightless birds are typically smaller or underdeveloped which restricts their them to fly. These birds, in turn, develop strong legs for running and specialized feet for swimming that help them to survive.
Reason of Flightlessness:
In most flightless birds, the reason is the shape of their body, for example, Ostriches, emus, cassowaries, rheas, and kiwis have flat breastbone which lacks the keel that anchors the strong pectoral muscles required for flight. Their small wings cannot lift their heavy bodies from the ground.
Also, the theory goes that birds evolved to become flightless due to lack of predators where they lived. They do not have many enemies, so did not really need to escape.
The flightless birds lost their ability to fly through evolution also. The well-known such birds are Dodo, Emperor Penguin, King Penguin, Little Penguin, Great Auk, Adelie Penguin, Cormorant, Gentoo Penguin, Common Ostrich Emu and much more.
Thus the reasons for flightlessness can be shortlisted as:
- Loss of their ability to fly through evolution
- The shape of their body and the design of wings
- Lack of predators and enemies in those areas
- An abundance of natural food sources.
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