Never known of a bluebird crawling, it would be difficult..To exclude house sparrows, make the entrance hole around one and a quarter inches across..Also, place the nest box no higher than five feet from the ground, sparrows won't nest so low.
Bluebirds, Blue Jays, and certain Parrots, and Parakeets can be blue.
Robins lay blue eggs, Araucana chickens lay blue eggs. Some grouse lay blue eggs as do Ardea Herodias (Great Blue Heron) The California Condor also lays a blue egg.
Bunting is the name of a certain group of birds that live in Africa and Eurasia. They are very similar to sparrows and finches.
Certain people believe they are attracted to the color blue but others say it's a myth.
The measure of change in elevation in a certain distance is called gradient.
The distance from start at which a certain object is located at a certain time.
Yes, "somewhere" contains the prefix "some-" which means a certain or unspecified amount or number.
Wrens, bluebirds and tree swallows are the birds most commonly attracted to single-unit, enclosed bird houses. Each species prefers certain locations and habitats in which to nest and rear its young. Your welcome
It is a plane perpendicular to the lens at the focal distance from the lens. All parallel light entering the lens from a certain direction falls on a single point somewhere on this plane. Where the point of light falls depends on what angle the "wall" of light enters the lens.
it is its speed
The velocity of the object.
That's a circle.