Better stay together: pair bond duration increases individual fitness independent of age-related variation

Abstract

Prolonged pair bonds have the potential to improve reproductive performance of socially monogamous animals by increasing pair familiarity and enhancing coordination and cooperation between pair members. However, this has proved very difficult to test robustly because of important confounds such as age and reproductive experience. Here, we address limitations of previous studies and provide a rigorous test of the mate familiarity effect in the socially monogamous blue-footed booby, Sula nebouxii, a long-lived marine bird with a high divorce rate. Taking advantage of a natural disassociation between age and pair bond duration in this species, and applying a novel analytical approach to a 24 year database, we found that those pairs which have been together for longer establish their clutches five weeks earlier in the season, hatch more of their eggs and produce 35% more fledglings, regardless of age and reproductive experience. Our results demonstrate that pair bond duration increases individual fitness and further suggest that synergistic effects between a male and female's behaviour are likely to be involved in generating a mate familiarity effect. These findings help to explain the age-and experience-independent benefits of remating and their role in life-history evolution.

Mate similarity in foraging Kerguelen shags: a combined bio-logging and stable isotope investigation

“…Positive assortment by behaviour has been shown in a few studies in groups such as birds (Both et al 2005, Schuett et al 2011, fishes (Budaev et al 1999), and cephalopods (Sinn et al 2006). In other contexts, better reproductive outcomes might be associated with the fact that more similar individuals exhibit improved cooperation and coordination, leading, for example, to better provisioning of offspring (Spoon et al 2006, Schuett et al 2010, Sánchez-Macouzet et al 2014. This might explain the fact that mates were more similar to each other at incubation/ early chick-rearing compared to late chick-rearing, as increased cooperation and coordination is more crucial when mates are incubating or guarding small chicks, as this is the period where parents are most at risk of losing their eggs or chicks through accidental dislodgement, predation, and/or hypothermy (Tve raa et al 1998, Kober & Gaston 2003, Catry et al 2006.…”

Becoming more like your mate: hormonal similarity reduces divorce rates in a wild songbird

“…Genomic DNA from both the nestlings and the parents were isolated using the PureGene DNA Isolation Kit (Gentra Systems, Minneapolis, MN, U.S.A.), and a polymerase chain reaction (PCR) was carried out using the Multiplex PCR kit (Qiagen). Five microsatellite regions (PmaTAGAn71, PmaGAn27, PmaTGAn33, PmaC25, PmaD105; Kawano, 2003;Saladin, Bonfils, Binz, & Richner, 2003) were amplified. PCR products were run on an ABI PRISM 3130 Genetic Analyzer (Applied Biosystems, Foster City, CA, U.S.A.) with a molecular size standard (GeneScan-500 LIZ, Applied Biosystems).…”

“…For example, disassortative mating based on boldness behaviour in guppies, Poecilia reticulata, decreases reproductive success (Ariyomo & Watt, 2013). Stable, long-term pair bonds have high reproductive success (Adkins-Regan & Tomaszycki, 2007;Black, 2001;S anchez-Macouzet, Rodríguez, & Drummond, 2014), whereas unsuccessful pairs can separate, which in turn results in physiological costs and reduced reproductive success (Angelier, Moe, Clement-Chastel, Bech, & Chastel, 2007;Black, 2001;Choudhury, 1995). These costs result from a lack of coordination among new pair members or from the stress associated with forced or natural pair separation (Catry, Ratcliffe, & Furness, 1997;Dhondt & Adriaensen, 1994;Remage-Healey, Adkins-Regan, & Romero, 2003).…”

Male feeding contribution facilitates multiple brooding in a biparental songbird

“…, Sánchez‐Macouzet et al . ). Therefore, the positive feedback of enhanced survival and reproduction can result in the evolution and maintenance of biparental care.…”