Page 64 - Design in Nature

The woodpecker can easily
reach larva hidden in tree
DESIGN trunks by its tongue. Humming
birds can collect flower nectar
IN BIRDS by using their slim, forked
tongues.

Blind spot
Blind spot

Binocular Binocular
vision vision

Eyes located on both sides of head The rain bird
provide the pigeon with a very moves extremely
wide visual field (orange and fast with swift
yellow areas). manoeuvres in
the air, which
requires an even
wider visual field
than most birds.
Large eyes
The most advanced senses of birds are vision
located on both
and hearing. Birds that usually hunt by day sides of its head
have better visual faculties. The hearing of provide this field
birds that prey at night is superior to other
of vision.
faculties.
Some birds that hunt by diving, such as herons
and cormorants, are equipped with eye
structures that enable them to see effectively The eyes of an
in water. The cornea of their eyes is flatter, owl are located to
which gives refraction and better vision. the front of its
The eyes of most birds are located on both head. This design
sides of the head. Hence, they have a wide provides the bird
angle of view. with a superb
The frontal location of the eyes of wild birds "binocular" vision.
that prey at night is another flawless design Yet it also creates
because these birds require "binocular" vision a wide blind field.
more than a wide angle view, and binocular This blind field is
vision (the area in which both eyes can see an by no means
object) has a narrow angle of view but more For some birds, a keen disadvantageous
depth and focus just as does human vision. sense of smell is vitally to the bird since it
Birds have other interesting senses as well, important. The black can rotate its head
which enable them not only to perceive vulture can locate 270 degrees and
vibrations in the air but also to navigate their carcasses from great look behind itself
routes by following the magnetic fields of the distances because of easily.
earth. its advanced sense of
smell.