Often regarded as additional race kirhizica, the rock sparrow or rock petronia (Petronia petronia), somewhat smaller birds from the Caspian region E to Kyrgyzstan, but distinctions from the intermediate seem insufficient to warrant separation. Within the sparrow family Passeridae, it is a small passerine bird. It is the only member of the Petronia genus. As race madeirensis, but inseparable from nominate, birds from Atlantic islands suggested. It breeds in southern Europe and across the Palearctic Siberia and north and central China on barren rocky hills from the Iberian peninsula and western northern Africa. It remains mostly in the west of its range, but Asian birds migrate or travel down the mountains to more southern areas. The Rock Sparrow is very similar to the House Sparrow female, but with a shorter, spotted whitetail, stronger bill, and wider legs, it is bulkier. The first systematic description of the rock sparrow was in the twelfth edition of his Systema Naturae by the Swedish naturalist Carl Linnaeus in 1766. The binomial name Fringilla petronia was invented by him. It is now the only species in the Petronia genus to have been introduced in 1829 by the German naturalist Johann Jakob Kaup. Petronia is a local name from the Bologna region of Italy for the rock sparrow. Resident and partial migrants; some dispersal post-breeding and winter withdrawal to lower altitudes. Race intermediaries have also been detected in Afghanistan, Kashmir, and Pakistan in winter. With blackish patches and stripes, the upper parts are dark brown. White, well visible in flight, the tips of the rectrices are spotted.
The scale of the rock sparrow is similar to a house sparrow, but with a larger bill that is more conical. With a clear white supercilium and a weaker crown stripe, it is about 14 cm (5.5 in) in length. The underparts are whitish, streaked brown, extending to the feathers of the flanks and under the tail. The bill is powerful and conical. It is brown on the upper mandible, from horn to dark brown, and on the lower mandible, it is yellowish. They have dark brown skin. There are light brown or pinkish-brown legs and feet; both sexes are identical. The juvenile is identical to adults, but the yellow throat-patch is absent and has browner plumage. North of its breeding range, it is a rare vagrant. There is only one record from Great Britain, on 14 June 1981 at Cley, Norfolk. In human settlements in the appropriate region, this gregarious bird is also found. The Rock Sparrow is a typical Mediterranean species; it frequents stony areas with short grass, arid and stony fields, mountainous areas, and monuments. Nestlings feed primarily on invertebrates, especially Lepidoptera caterpillars and grasshoppers (Orthoptera). Food was often gathered on the ground, but some insects were caught in flight. In pairs and in small flocks, in larger flocks also. Both males and females contribute equally to the treatment of the young in Asian colonies. Males of larger sizes feed their young at higher rates, suggesting that better territories are held by larger males and/or better fathers. Studies have found a strong association between the size of the male yellow breast patch and the length of the nestling tarsus, which means that better parents are often more ornamented males. As the season progresses, females increase the amount of non-feeding visits to their nest, indicating that it is more desirable to help the survival of their current offspring because females have fewer chances to lay other clutches. A positive relationship has been reported between the number of deserting females and the number of males available. The Rock Sparrow breeds in southern Europe, across southern Europe and central Asia, from the Iberian Peninsula and western North Africa. After the breeding season and during winter, the Asian populations migrate southwards or conduct altitudinal movements. In April-May, the female lays 4-5 eggs, sometimes six at higher altitudes, where the second clutch is not certain. The eggs are white, blackish, or spotted brown. The larger base is typically darker, but other eggs with greyish speckles may be very pale, or almost entirely greenish-white. The incubation by the female lasts for about 12-15 days. During this process, she is fed by the male. The chicks are partly shrouded indoors at hatching. Both adults carefully rear them, but they develop very slowly and stay in the nest for at least 20 to 22 days. It feeds primarily on insects, grasshoppers, and caterpillars throughout spring and summer, but it also needs cherries and other fruits.
