Effects of behavioural time budgets and nest-building efficiency on male reproductive performance in red bishops (Euplectes orix)

Abstract

In this study we have investigated the effect of nest-building behaviour, courtship behaviour, and male-male interactions on male reproductive performance of the red bishop (Euplectes orix), a highly polygynous, colonially breeding weaverbird species. Previous studies on red bishops have revealed that male reproductive success is mainly determined by the number of nests built in a territory, and that reproductive success and the number of nests both vary substantially among males. Here we test whether the high variation observed in reproductive performance is related to male behavioural patterns (as assessed by time-budget analysis) and/or nest-building efficiency (as assessed by the number of fibres incorporated in the nest in unit time). We collected data on male time budgets and analysed behavioural patterns for three breeding seasons. A greater number of nests built was positively related to both the amount of time allocated to nest-building behaviour and the efficiency of nest building. Neither the amount of time spent in courtship behaviour nor the amount of time spent in male-male interactions was related to reproductive success. Male reproductive success, irrespective of the number of nests built, was partly determined by the number of fibres incorporated, suggesting some importance of nest quality in terms of nest chamber density to male reproductive success. There were no trade-offs with regard to time allocated to different behaviour. Instead, males differed with regard to their territory attendance and activity levels, which might be because of differences in energy resources and may thus reflect inherent differences in male body condition and, ultimately, male genetic quality.

Nest-building males trade off material collection costs with territory value

“…Male Cape Weavers that built more nests were more likely to attract females as are Long-billed Marsh Wrens (Telmatodytes palustris) (Verner and Engelsen 1970), Eurasian Wrens (Troglodytes troglodytes) (Verner and Engelsen 1970;Garson 1979) and various weavers including: Southern Red Bishop (Euplectes orix) (Friedl and Klump 2000;Lawes et al 2002;Metz et al 2007;Metz et al 2009), andVillage Weaver (McAlary et al 1984). The costs of spending more time on the territory, therefore, appears to be counterbalanced by the benefit of females being more likely to choose a nest built by a male who has more nests in his territory.…”

Linking male reproductive success to effort within and among nests in a co‐breeding stream fish

“…Thus, allocation of current and future efforts, such as investment in current reproduction as opposed to survival and growth, determines lifetime reproductive success (Dubuc et al, 2014; Galimberti et al, 2007; Tarwater & Arcese, 2017). The effect of male efforts on reproductive success has been well documented in many animal taxa, whereas little is understood about how males allocate reproductive effort for successful reproduction within a breeding season (Andersson, 1994; Dubuc et al, 2014; Metz et al, 2007; Reynolds, 1996).…”

“…Such co‐breeding behavior is observed in some nest‐building species, in which males construct nests to attract females and provide parental care of the young in aquatic and terrestrial animals (Barber, 2013; Gross, 2005; Soler et al, 1998). As nest construction is energetically costly, males typically own their nests and spend much effort on nest construction and defense (Bose et al, 2018; Lehtonen et al, 2007; Metz et al, 2007; Soler et al, 1998). But in some species, males co‐breed with other males by building and sharing nests (Díaz‐Muñoz et al, 2014; Gross, 1996; Taborsky, 2009).…”

Linking Male Reproductive Success to Effort Within and Among Nests in a Co-Breeding Stream Fish

“…Therefore, allocation of reproductive effort is a key topic in behavioral and evolutionary biology, and this has been most frequently investigated in the context of lifetime reproductive success (Merilä and Sheldon 2000;Dubuc et al 2014). Less is understood about how males allocate reproductive effort within a spawning season to increase reproductive success (e.g., Metz et al 2007), despite the common pattern that reproductive success varies greatly among males in polygamous mating systems (Andersson 1994;Dubuc et al 2014).…”