Pet bird features
- Body mechanisms that put a Swiss watch to shame
- A coat of thousands of feathers requiring constant maintenance
- Eyes that see invisible (to you & me) light
- Beaks that can crack large nuts or hull tiny seeds
- Use of flight to travel 3 dimensionally throughout your home
- Can land then stand on any 3 square inch surface
- Knows what time it is – precisely
- Can detect the motion of the sun
- Solves problems
- (Some) can verbalize
- Can pre-plan events into the future
- Can do all of this for decades
makes caged bird keeping the most challenging of traditional pet husbandry.
The science of bird sight
Good eyesight is imperative for flight safety and birds eyesight is much better than that of any other species having vertebrae. It’s been said that pigeons are nothing more than two eyes and a pair of wings. Birds eyes are similar to that of reptiles, meaning the shape of the lens can change quickly, much more quickly than we mammals.
Birds have the largest eyes relative to their body size of any animal on the planet. Raptors have very large eyes for their size, 1.4 times greater than the average for birds of the same weight, and the eye is tube-shaped to produce a larger retinal image. But the movement of the eye is limited because birds eyes have a bony socket. Most vertebrates have two eye lids, birds have a third transparent membrane that is movable which is unique to birds.
Birds have four types of color receptors in the eye (unlike humans who have 3). That means birds are able to see the ultraviolet part of the light spectrum – light that is not visible to you nor I. They also have far more light receptors in their retinas than mammals and more nerve connections between the photo receptors in the brain. This is whyproper lighting for your bird is so important.
Many birds in the wild show plumage patterns that are actually ultraviolet and invisible to we humans. Some birds who appear to be monomorphic (cannot tell the sex of the bird by their colors) to the naked eye can be sexually distinguished by the presence of ultraviolet reflective patches on their feathers – but only by other birds.
Birds can also resolve rapid movements of light far better than humans. Neither you nor I can distinguish the individual flashes of a florescent light oscillating at 60 Hz BUT Budgerigars and chickens have flicker thresholds at more than 100 Hz. A Cooper’s Hawk can pursue prey through heavily forested woodland, avoiding collisions at high speeds which If you are I were to try to keep up – would all appear as a blur.
Birds can even detect the motion of extremely slow-moving objects like the sun and constellations across the sky (think GPS attached to an altimeter but covered in feathers). Another thing humans cannot do without sophisticated instruments. Centuries ago, things like sextants (John Bird made the first sextant in 1757) were needed to figure out “where am I on the planet?” This 3 dimensional geographical accuracy is instinctive to our feathered companions. Birds use celestial movements to properly orient themselves in relation to the earth’s surface.