Quaker parakeets (Myiopsitta monachus), ... (28 centimeters) to 13 inches (33 centimeters) from their head to the end of their long tail. Quaker parakeet colors are mostly green or gray, ...

Yet bird-watching hones a sharp eye for color differentiation, so Ridgway had an edge — as well as a drive for perfection enabled by 19th-century synthetic dye advancements.

While humans have three color cones in the retina sensitive to red, green and blue light, birds have a fourth color cone that can detect ultraviolet light. A Princeton-led research team trained wild ...

This is the year of mocha mousse, according to Pantone. The company's annual color craze originates in part from the work of a 19th-century ornithologist who described the dizzying array of bird ...