Social factors affect the singing rates of female northern cardinals Cardinalis cardinalis

摘要: Social factors, such as the duration of territorial occupancy or time paired with a mate can affect rate at which individual birds sing. This study examined influence pair-bond and territory well date on singing by male female northern cardinals Cardinalis cardinalis. When differences in breeding status were controlled, sang higher rates earlier season. Females newly formed pairs significantly than those that had previously bred together. In contrast, did not show significant variation throughout The song males established differ significantly. Song for females mated correlated. suggests social factors have strong effect It is possible increased intra-sexual aggression when they are establishing new leads to this level output. Once acquired mate, dear-enemy effects might diminish need acoustic defence. Differences constraints nesting attraction extra-pair mates explain sexual behaviour.