Which of these birds are primarily seed-eaters?

Passer sparrows are primarily ground-feeding seed-eaters, though they also consume small insects especially when breeding. A few species, like the house sparrow and northern grey-headed sparrow scavenge for food around cities, and are almost omnivorous. Most Passer species are gregarious and will form substantial flocks.

Most of its members are found naturally in open habitats in the warmer climates of Africa and southern Eurasia.

Passer sparrows build an untidy nest, which, depending on species and nest site availability, may be in a bush or tree, a natural hole in a tree, in a building or in thatch, or in the fabric of the nest of species such as the white stork. The clutch of up to eight eggs is incubated by both parents typically for 12–14 days, with another 14–24 more days to fledging.