Question

Which bird do not fly without ostrich and hen ​

Answer 1

Flightless birds:

• Flightless birds are birds that through evloution lost the ability to fly. There are over 60 extant species , including the well known ratites ( ostrich, emu, cassowaries, rheas,kiwi).
• The smallest flightless bird is the inaccessible island rail. The largest flightless bird which also the largest living bird (ostrich).
• Flightlessness has evolved in many different birds independently. There were a families of flightless birds, such as the now extinct Phorusrhacidae, that evolved to be powerful terrestrial predators.
• Further more, they also share traits of being giant, flightless birds with vestigial wings, long legs and long necks with some of the ratites, they are not related.
• Two key differences between flying flightless birds are the smaller wing bones and the absent on their breastbone.
• Flight is the most costly types of locomotion exemplified in the natural world. The energy expenditure required for flight increase proportionality with body size.

Answer 2

answer:

emu also does not fly