Data from: Mate guarding and frequent copulation in birds: a meta-analysis of their relationship to paternity and male phenotype|鸟类行为学数据集|进化生物学数据集

In many birds males are presumed to protect their paternity by closely guarding their mate or copulating frequently with her. Both these costly behaviours are assumed to reduce the risk and/or intensity of sperm competition. However, despite many studies on avian extra-pair paternity, it remains unclear how strongly these behaviours are related to fitness and other key life-history traits. Here we conduct meta-analyses to address two questions. First, are mate guarding and/or frequent copulation positively correlated with a male's share of paternity at his nest? We find a significant positive correlation between both presumed paternity protection behaviours and paternity share. The relationship is, however, weak (r = 0.08-0.23). This is perhaps unsurprising if the risk of partner infidelity, hence the need to protect paternity, varies among males. For example, more attractive males might have less need to protect their paternity. Second, do males with higher indices of so-called male ‘quality’ (phenotypic measures, usually subjectively defined by researchers as predictors of male attractiveness) exhibit lower levels of paternity protection behaviour? We find a negative correlation between male quality and paternity protection. This finding might partly explain the weak relationship between paternity protection and paternity, although we discuss other, non-mutually exclusive possibilities.