The Spanish sparrow feeds mainly on vegetable matter, mostly consisting of the seeds of grasses and cultivated crops such as wheat, millet, barley and oats. It also feeds on leaves and fruit, and occasionally takes some insects, usually caterpillars, grasshoppers and flying ants (4). For the first half of their nestling period, the chicks of the Spanish sparrow are fed almost entirely on insects (3).
Spanish sparrows often breed in large colonies, sometimes of up to several hundred thousand pairs. The nests are packed close together, often with over one hundred nests in a single tree. The nest is built by both sexes and consists of a loosely woven, spherical structure of grass and plant stems. The inside is lined with fine grass and feathers. The whole nest is usually found firmly attached to branches of a tree, or may be built in the lower part of the nest of a bird of prey, or on a pylon (3).
The Spanish sparrow produces clutches of about 2 to 6 eggs, which are incubated by both sexes for 10 to 11 days. The chicks and fledglings are tended by both adults.
As a gregarious species, the Spanish sparrow takes part in many social activities, including ‘social singing’, in which the birds call together from bushes and trees. Groups of sparrows also dust bathe together, rolling in dust or sand on the ground in order to clean the feathers and remove parasites (6). Over one hundred Spanish sparrows have been known to take dust baths together (3).
The Spanish sparrow is generally a shy species, and even when feeding in crops will fly off for quite a distance if disturbed (4).