Editing Rock sparrow (section)

===Breeding===
It nests in crevices in rocks or walls, laying four to five [[bird egg|eggs]].{{sfn|Cramp|1994|p=396}} Rock sparrows exhibit a variety of mating patterns, most notably monogamy and sequential and simultaneous [[Polyandry in animals|polyandry]]; however, social monogamy is the most abundant mating pattern. The frequencies of these various mating patterns most likely vary with numerous ecological and social factors. Many studies have shown that both males and females prefer a mate with a larger yellow patch. It has also been shown that male brood defence behaviours increase with greater female ornamentation. Males also differentially allocate parental investment according to female ornamentation; this behaviour is not observed in females. In alpine colonies of ''Petronia petronia'', females perform most of the provisioning. In Asian colonies, both males and females contribute equally to the care of the young. Males of larger sizes feed their young at higher rates, which suggests that larger males occupy better territories and/or are better fathers. Studies have found a positive correlation between male yellow breast patch size and nestling tarsus length, which suggests that more ornamented males are also better parents. Females increase the number of non-feeding visits to their nest as the season progresses, suggesting that because females have lesser opportunities to lay other clutches, it is most advantageous to support the survival of their current offspring. A positive relationship between the number of deserting females and the number of available males has been recorded.<ref name=garcia/>