Females are more determinant than males in reproductive performance in the house sparrow Passer domesticus

Abstract

Which sex has a more determinant role in reproductive performance? This is a long standing question in evolutionary ecology. Theory predicts and several pieces of evidence have indicated that females are more determinant than males. However, a direct test of this hypothesis has never been made. Here we perform such a direct test by using an alternative analytical approach, controlling for age and/or individual experience, and a captive population of the house sparrow Passer domesticus, a monogamous bi‐parental dimorphic species in which both sexes contribute with approximately equal amounts of parental care. In this species, it has been demonstrated that contribution by males to offspring parental care is crucial to maximize reproductive success. Captive conditions with absence of predators and availability of food ad libitum allow us to control several important factors that may affect reproductive performance, such as environmental fluctuations in resource availability and differences in territory quality, without affecting reproductive performance. We consider four types of pairs, and our main prediction derived from the hypothesis is that mixed pairs involving an experienced female (FBM × EF) should present better reproductive performance than mixed pairs involving a first‐time breeder female (EM × FBF). Our results confirm the general pattern reported in other bird species that older or more experienced individuals enjoy a higher reproductive success than first‐time breeders. In addition, in agreement with our main prediction, we found that FBM × EF produced significantly more fledglings and had higher fledging success than EM × FBF. Our results, for the first time demonstrate the broadly accepted statement that females have a more determinant role than males in reproductive performance.

Does the Urban Environment Act as a Filter on the Individual Quality of Birds?

“…This implies that individual quality can vary over time. In fact, experimented birds tend to have a better reproductive success than first-year breeders [8,11,12], and the maturation hypothesis [13] supports the suggesting that this may be due to improvements in some skills, such as foraging ability [12], better timing of reproduction [14,15], or the increasing efficiency of the endocrine system (i.e., increase in prolactin levels) [16].…”

“…However, too harsh conditions may decrease the heterogeneity due to the important mortality of poor-quality birds, leading to a homogenization of the phenotypes. For a given phenotype, individual performance can also fluctuate with age and/or experience [8][9][10]. This implies that individual quality can vary over time.…”

Microbiota composition and diversity of multiple body sites vary according to reproductive performance in a seabird

“…Altogether, these results suggest that, in kittiwake pairs, reproductive outcome from the decision to lay eggs to hatching is mainly due to females. Accordingly, in several monogamous birds with biparental care including kittiwakes (Jacobsen, Erikstad, & Saether, 1995;Leclaire et al, 2010), females have been suggested to be more determinant of reproductive performance than males (Peralta-Sánchez, Colmenero, Redondo-Sánchez, Ontanilla, & Soler, 2020;Slagsvold & Lifjeld, 1990).…”

Sex-dependent risk-taking behaviour towards different predatory stimuli in the collared flycatcher

“…Sexes could differ in their roles and investments during the breeding season, independently of the environmental factors (Hogstad, 2005). In some species, the role of each sex is similar (Massoni et al, 2012;Wojczulanis-Jakubas et al, 2016), while in other species, sexes allocate parental care in a different manner (Paredes et al, 2006;Peralta-Sanchez et al, 2020). In passerines, it is common that females invest more energy in the current brood as they form, lay and incubate the eggs (Reid et al, 2002;Tinbergen and Williams, 2002;Goullaud et al, 2018).…”