Question

Which bird can not fly?
A. Stork
B. Emu
C. Duck
D. Peacock

Answer 1

Hint: The organisms belonging to superclass aves are characterized by the ability to take flight. But unlike most of the birds, there are some unique ones who don’t have the ability to fly due to certain morphological differences from the other birds. Their small and weak wings are not efficient enough to lift their heavy bodies off the ground.

Complete answer: Flightless birds such as emu and ostriches have unique flat breastbones that don’t have the keel which is necessary for anchoring the well-built pectoral muscles needed for flying.
An abundance of food and a lack of predators that followed the extinction of dinosaurs viewed a number of birds evolving and becoming heavier in mass which made it difficult for them to take flight.
Birds like the emu and ostrich gave up on flying because they became fat and lazy when the dinosaurs perished, according to new studies conducted by scientists.

So, the correct answer is option B. Emu.

Note: There are many scientists who strongly believe that the ancestors of modern flightless birds were also flightless but more recent research has come up with the possibility that their ancestors could actually fly, but stopped making that effort. This evolution has been gradual and resulted in these flightless birds.