This cosmopolitan species was introduced from Europe to Brooklyn, N.Y., in 1850 and into Ontario in about 1870. It spread rapidly and was considered a pest by the end of the century. It was much more abundant in the days of horse-drawn transportation than it is now, living on waste grain and droppings, but it is still one of the most abundant species near human habitations, becoming increasingly rare in Northern Ontario where it is found mainly near settlements and farms and absent from large, unsettled areas. Although usually considered nonmigratory I have witnessed flocks taking off over Lake Erie from Point Pelee. Nests are usually built in cavities under the eaves of houses or other buildings, or in bird boxes designed for other species but some build big globe-shaped nests about the size of a football in trees, more fitting for a member of the Ploceidae (the weaver finches).
Males with their gray crowns, chestnut napes, white cheeks and black bibs (reduced to the chin in winter) are easily identified, and their dingy mates by association with them.
Males are sometimes confused with the rare Harris’ Sparrow because both have black bibs (but the Harris also has a black crown).