General Overview
The Passeridae family, commonly known as Old World sparrows, includes about 40 species of small passerine birds distributed across Europe, Asia, and Africa, with a few species introduced to the Americas and Australia. The house sparrow (Passer domesticus), in particular, has become one of the most widespread and familiar birds in the world due to its close association with humans. Unlike the New World sparrows (family Passerellidae), Passeridae are a distinct lineage. They are hardy, adaptable birds often thriving in urban, rural, and agricultural environments.
Appearance
Old World sparrows are small, stout-bodied birds, typically measuring 12–18 cm in length. They have short, conical bills well-suited for seed-eating and relatively plain plumage, usually in shades of brown, gray, black, and buff. Many species exhibit sexual dimorphism: males often have bold markings such as black throats or bibs, while females are more cryptically colored. Their plumage is not as vibrant as that of many finches, but their subtle patterns aid in camouflage.
Diet
Passerids are primarily granivorous, feeding on seeds and grains, though they also consume insects, especially during the breeding season to provide protein for chicks. Their opportunistic diet allows them to thrive in human-dominated landscapes, where they readily feed on food scraps, crops, and garden seeds. They may also forage on fruits and small invertebrates depending on availability.
Habitat
Members of the Passeridae family are highly adaptable and occupy a wide range of habitats, including grasslands, savannas, scrub, woodlands, and deserts. Many species have become strongly synanthropic, living in villages, towns, and cities alongside humans. Nesting occurs in tree cavities, rock crevices, buildings, and artificial structures, often in loose colonies.
Behavior
Old World sparrows are highly social birds, often seen in flocks outside the breeding season. They exhibit a wide range of vocalizations, including simple chirps, chatter, and communal calls that help maintain flock cohesion. Breeding systems are typically monogamous, though polygyny can occur. Nests are bulky structures made of grass, twigs, and feathers, and both parents share incubation and chick-rearing duties. Sparrows are aggressive defenders of nesting sites and compete with other cavity-nesting birds. Their adaptability, social nature, and tolerance for human presence have made them among the most successful bird families worldwide.
