Old World Sparrows are small passerine birds belonging to the family Passeridae, commonly known as true sparrows. They differ from New World sparrows in the family Passerellidae and from other birds like the Java sparrow.
Many Old World sparrows, such as the house sparrow and the Eurasian tree sparrow, nest in urban areas and are often found in large numbers. They primarily feed on seeds but also eat small insects and scavenged food.
These birds are typically small and plump, with brown and grey plumage, short tails, and strong beaks. Their size varies; for example, the chestnut sparrow measures about 11.4 cm (4.5 inches) and weighs around 13.4 grams (0.47 ounces), while the parrot-billed sparrow is about 18 cm (7.1 inches) long and weighs approximately 42 grams (1.5 ounces).
Old World sparrows have a vestigial dorsal outer primary wing feather and an extra bone in their tongues, called the preglossale, which helps them hold seeds. They also feature specialized bills and elongated digestive tracts adapted for seed eating.
