An experimental increase in female mass during the fertile phase leads to higher levels of extra-pair paternity in pied flycatchers Ficedula hypoleuca

Abstract

Female mass in most altricial birds reaches its maximum during breeding at egg laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), which may impair flight efficiency and thereby reduce female's capacity to resist unwanted extra-pair male approaches (sexual conflict hypothesis). On the other hand, it would enhance female condition, favouring her capacity to evade mate guarding and to search for extra-pair mates (female choice hypothesis). In both cases, higher female mass at laying may lead to enhanced EPP. To test this prediction, we reduced nest building effort by adding a completely constructed nest in an experimental group of female pied flycatchers (Ficedula hypoleuca). Our treatment caused an increase in mass and thereby wing loading and this was translated into a significantly higher EPP in the manipulated group compared with the control group as expected. There was also a significant negative relationship between EPP and laying date and the extent of the white wing patch, an index of female dominance. More body reserves at laying mean not only a higher potential fecundity but a higher level of EPP as well. This interaction had not previously received due attention but should be considered in future studies of avian breeding strategies. Significance statementWhile most research has been focused on determining possible criteria for extra-pair mate choice by females, less effort has been made on establishing if female traits are related to EPP and its intensity. One such trait is mass at laying which attains its highest level for breeding females of altricial birds. Our study indicates that a higher mass during the fertile phase not only has implications for female fecundity and predation risk but also for EPP in the resulting brood as more mass means a higher EPP.

Disentangling the age-dependent causal pathways affecting multiple paternity in house sparrows

“…The lack of an effect of body mass is perhaps unsurprising, as we only investigated the role of body mass between individuals. However, within-individual relative body mass has previously been found to affect MP in pied flycatchers ( Ficedula hypoleuca ), likely through the time needed to forage versus obtain EPP [77]. The absence of any effect of breeding synchrony on female MP in the first clutch per year in this house sparrow metapopulation (measured per island per year) is interesting given that it has been found to be a driver in other bird species via the availability of extra-pair mating opportunities [45].…”

Extra‐pair paternity is not repeatable between years in Pied Flycatchers (Ficedula hypoleuca): a role for social context

“…Type-it kits (Qiagen) were used to amplify approximately 5 ng of template DNA in the multiplex polymerase chain reactions. For detailed descriptions of family genotyping see Plaza et al (2019aPlaza et al ( , 2019b.…”

“…We considered that chicks were the offspring of the adults if their genotypes were compatible for the assigned loci. For a detailed description of paternity assignment see Plaza et al (2019aPlaza et al ( , 2019b.…”

Male aggressiveness during the female fertile phase in relation to extra-pair paternity, plumage ornaments and female traits

“…We collected samples from 64 broods at 13 days of age and their two attending mates (125 adults, 304 nestlings). EPP analyses were performed following the protocol used in Plaza et al (2019a) and, for each nest, two variables were calculated from the paternity analysis: presence/absence of EPP (indicated by 1 and 0, respectively) and the proportion of EPP (proportion of the brood fathered by males other than the attending male).…”