Rock Sparrow (Petronia petronia)

This sparrow measures from 15-17 cm in total length. The plumage of both sexes is very similar, which is quite the opposite for other species of the genus Passer. The adults have a marked whitish line over the eye, a tiny yellow blotch on the breast and a brown back with pale patches. The tip of the tail is speckled white, and the bill is rather stubby and well-adapted to the bird’s diet. This sparrow only breeds in Madeira (including Porto Santo) and the Canaries (Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro). A subspecies, P. p. madeirensis, described for both archipelagos, requires further genetic studies to clarify the situation. This essentially rock-dwelling passerine inhabits cliffs, ravines, stone hedges around pastureland and crops, and urban areas. In Madeira it is also found on some coastal rocks and islets. In the past it was a frequent visitor to towns and villages, but this is seldom the case at present. It feeds mainly on grain, but its diet also includes insects and other invertebrates (particularly during the nesting season), as well as fruit. It favours abandoned cultivated terraces and often gathers in large flocks to feed. Breeding starts in January-February, when courtship begins, and clutches (4-6 eggs) are produced in March and June, and occasionally in July. Nests are built in the cracks and hollows of stone walls, buildings and rocky peaks, hence the vernacular name of this species. Populations in Madeira and the Canaries have declined dramatically in the past few decades, to the point of near extinction on some islands (e.g., La Palma), while distribution is very restricted on others. Factors that have a negative impact include agricultural changes (mainly associated with reduced cereal production), alleged competition from the Spanish sparrow (Passer hispaniolensis) and, in all likelihood, predation by introduced mammals and the use of chemical products in farming.