Eileen Tiller, of Kapiti Coast, asks :-

Why do some birds walk but others hop?

Jim Briskie, a zoologist at the University of Canterbury, responded.

Hopping is more common among arboreal species of birds (those living in trees), although there are exceptions and body size is also a factor.

Arboreal species hop from branch to branch as they forage and move around, but when on the ground (as they are occasionally, such as house sparrows), such hopping in trees also leads to a hopping gait on the ground.

On the other hand, terrestrial birds such as chickens or pukekos, that primarily live on the ground are more inclined to run and have a smoother walking gait.

Larger species are also more likely to walk while smaller species hop. There is some evidence that hopping in small birds with short legs is more energy efficient while the reverse is true (i.e., walking is more energy efficient) for bigger and longer-legged species.

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