why kiwi or ostrich cannot fly?

Answer 1

Ostriches are a heavy bird and its wings can not support its weight but instead are built for running. . They can sprint in short bursts up to 43 miles per hour, and they can maintain a steady speed of 31 miles per hour.
Why do they have wings? Ostriches hold their wings out to help them balance when they run, especially if they suddenly change direction. Their main use, though, is for displays and courtship, along with the tail feathers.

The kiwi has a long, pointed bill, with nostrils at the end. Its feathers are brown, rough, and shaggy, and its wings are only 2 inches long and it has no tail, so it can not get its body of the ground. The kiwi has short but powerful legs which it uses to run, to burrow in the soil, and to kick. New Zealand is about 90 million years old, and mammals did not exist on the islands (except for three species of bats) until people arrived, about 1,000 years ago. So kiwi took the place of a burrowing type of mammal. Kiwis have been around for about 39 million years.

Answer 2

Ostriches are very heavy, almost they weigh around 90 - 130 kgs, and some of the male ostriches weigh 155 kgs.They have small vestigial wings and are used by males in mating displays. They can also provide shade for chicks. The feathers are soft and serve as insulation, and are quite different from the stiff airfoil feathers of flying birds; this making the main reason why they cannot fly.

and Kiwis too cannot fly because they have no keel on the breastbone to anchor wing muscles, and barely any wings either: the vestiges are so small that they are invisible under the kiwi's bristly, hair-like, two-branched feathers. While birds generally have hollow bones to save weight and make flight practicable, kiwi have marrow, in the style of mammals.

Answer 3

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RE:
why kiwi or ostrich cannot fly?

Answer 4

Kiwi is a fruit. Ostrich don't have big enough wings.

Answer 5

These birds cannot fly because the surface area to volume ratio of their wings to there body weight is too small...simply put.

Answer 6

They have wings that won't support flying their frames. Mass/weight to lift ratio.

Answer 7

These are flightless birds as their flight muscles are weak they cannot fly.

Answer 8

Ask a Penguin.

Answer 9

they dont have the wings prepared for that...