Birds have bilateral symmetry. This means the left and right sides of their body can be divided into an almost exact mirror image of each other. The line drawn down the middle of the body to divide the left and right sides is sometimes called the midline.
By having bilateral symmetry birds can fly well. Imagine what would happen if one wing was bigger or smaller than the other or if it was a completely different shape.
Ninja – really who would have thought 🙂
Symmetry is associated with speed and strength —> fighting ability / protect young. Experiments have been carried out to show female birds prefer more symmetrical mates as symmetry is an indicator of ‘good genes’.
Traits nature wants passed onto the young.
Symmetry is also a good indicator of health – more symmetrical less susceptible to diseases.