For most plants and animals, just listing the family, genus or species is enough to let biologists know what the other levels should be. The most common way to list the taxonomic name of an organism is to list the genus and species; this is known as binomial nomenclature, meaning a two-name system.
The grey jay is a relatively large songbird, though smaller than other jays. A typical adult grey jay is between 25 to 33 cm (9.8 to 13.0 in) long. Its wingspan is around 45 cm (18 in). It weighs about 65 to 70 g (2.3 to 2.5 oz). Adults have medium grey back feathers with a lighter grey underside.
House Sparrows are 5 to 6 inches in length. The male has a gray crown, whitish check, and black throat. The bill and breast are black in summer and in winter the bill is yellow and the breast is gray. The female has a brown crown and a plain breast with a broad buff line over the eye.