When should cuckolded males care for extra-pair offspring?

Abstract

In socially monogamous species with bi-parental care, males suffer reduced reproductive success if their mate engages in extra-pair copulations (EPCs). One might therefore expect that males should refuse to care for a brood if they can detect that an EPC has occurred. Here, we use a game-theory model to study male brood care in the face of EPCs in a cooperatively breeding species in which offspring help to raise their (half-) siblings in their parents' next breeding attempt. We show that under certain conditions males are selected to care even for broods completely unrelated to themselves. This counterintuitive result arises through a form of pseudo-reciprocity, whereby surviving extra-pair offspring, when helping to rear their younger half-siblings, can more than compensate for the cost incurred by the male that raised them. We argue that similar effects may not be limited to cooperative breeders, but may arise in various contexts in which cooperation between (half-) siblings occurs.

Variation in parent-offspring kinship in socially monogamous systems with extra-pair reproduction and inbreeding

“…). Paternal care for unrelated EPO has also been suggested to evolve if EPO help rear subsequent WPO (Liedtke and Fromhage ). Furthermore, male–male relatedness might also facilitate evolution of reproductive strategies involving leks and male coalitions (Shorey et al.…”

“…Indeed, helper contributions can increase with increasing relatedness (Griffin and West 2003;Nam et al 2010), and cooperative breeding is associated with low promiscuity (and hence high within-family relatedness) across species (Cornwallis et al 2010). Paternal care for unrelated EPO has also been suggested to evolve if EPO help rear subsequent WPO (Liedtke and Fromhage 2012). Furthermore, male-male relatedness might also facilitate evolution of reproductive strategies involving leks and male coalitions (Shorey et al 2000;Krakauer 2005;Hatchwell 2010a).…”

Who takes care of the kids and when? Sex differences in avian parental care

“…Although theories generally predict that males should invest more in the care of their genetic offspring and adjust their parental efforts to their share of paternity in the nest [12][13][14]61 , empirical supports have been mixed, with abundant exceptions where males do not seem to react to the loss of paternity by reducing their parental care efforts, such as in dunnocks 68,69 , reed buntings 70 , and western bluebirds 71 . Recent theoretical studies revealed some conditions where males may evolve to be insensitive to the loss of paternity, e.g., in cooperative breeding species where offspring help to raise their younger (half-)siblings 72 , or in the presence of male alternative reproductive tactics where the "sneaker" males specialize in gaining extra-pair paternity 73 . Empirical studies also found that in species where males were not sensitive to paternity loss, paternal care may not be costly in terms of parental survival 70 and/or the loss of opportunities for siring extra-pair offspring 37 .…”

Who takes care of the kids at when? Sex differences in avian parental care

“…Recent theoretical studies revealed some conditions where males may evolve to be insensitive to the loss of paternity, e.g. in cooperative breeding species where offspring help to raise their younger (half-)siblings [67], or in the presence of male alternative reproductive tactics where the "sneaker" males specialize in gaining extra-pair paternity [68]. Empirical studies also found that in species where males were not sensitive to paternity loss, paternal care may not be costly in terms of parental survival [30] and/or the loss of opportunities for siring extra-pair offspring [23].…”

“…Although theories generally predict that males should invest more in the care of their genetic offspring and adjust their parental efforts to their share of paternity in the nest [12][13][14]61 , empirical supports have been mixed, with abundant exceptions where males do not seem to react to the loss of paternity by reducing their parental care efforts, such as in dunnocks 68,69 , reed buntings 70 , and western bluebirds 71 . Recent theoretical studies revealed some conditions where males may evolve to be insensitive to the loss of paternity, e.g., in cooperative breeding species where offspring help to raise their younger (half-)siblings 72 , or in the presence of male alternative reproductive tactics where the "sneaker" males specialize in gaining extra-pair paternity 73 . Empirical studies also found that in species where males were not sensitive to paternity loss, paternal care may not be costly in terms of parental survival 70 and/or the loss of opportunities for siring extra-pair offspring 37 .…”