Biparental Care Of Offspring Research Articles

Introduction The 41–43 species of birds-of-paradise (Paradisaeidae) (Beehler & Pratt 2016; Gill & Donsker 2019) are renowned for their exquisite beauty and plumage, and their diversity of extraordinary courtship displays (Gilliard 1969; Cooper & Forshaw 1977; Coates 1990; Frith & Frith 2009; Laman & Scholes 2012; Ligon et al. 2018). Males of the majority of birds-of-paradise (35–37 species) are presumed

Introduction The 41–43 species of birds-of-paradise (Paradisaeidae) (Beehler & Pratt 2016; Gill & Donsker 2019) are renowned for their exquisite beauty and plumage, and their diversity of extraordinary courtship displays (Gilliard 1969; Cooper & Forshaw 1977; Coates 1990; Frith & Frith 2009; Laman & Scholes 2012; Ligon et al. 2018). Males of the majority of birds-of-paradise (35–37 species) are presumed

Brood-tending males in a biparental fish suffer high paternity losses but rarely cuckold.

Extra‐pair paternity within socially monogamous mating systems is well studied in birds and mammals but rather neglected in other animal taxa. In fishes, social monogamy has evolved several times but few studies have investigated the extent to which pair‐bonded male fish lose fertilizations to cuckolders and gain extra‐pair fertilizations themselves. We address this gap and present genetic paternity data collected from a wild population of Variabilichromis moorii, a socially monogamous African cichlid with biparental care of offspring. We show that brood‐tending, pair‐bonded males suffer exceptionally high paternity losses, siring only 63% of the offspring produced by their female partners on average. The number of cuckolders per brood ranged up to nine and yet, surprisingly, brood‐tending males in the population were rarely the culprits. Brood‐tending males sired very few extra‐pair offspring, despite breeding in close proximity to one another. While unpaired males were largely responsible for the cuckoldry, pair‐bonded males still enjoyed higher fertilization success than individual unpaired males. We discuss these results in the context of ecological and phenotypic constraints on cuckoldry and the fitness payoffs of alternative male tactics. Our study provides new insights into how pair‐bonded males handle the trade‐off between securing within‐pair and extra‐pair reproduction.

Intergenerational transmission of alloparental behavior and oxytocin and vasopressin receptor distribution in the prairie vole.

Variation in the early environment has the potential to permanently alter offspring behavior and development. We have previously shown that naturally occurring variation in biparental care of offspring in the prairie vole is related to differences in social behavior of the offspring. It was not, however, clear whether the behavioral differences seen between offspring receiving high compared to low amounts of parental care were the result of different care experiences or were due to shared genetics with their high-contact or low-contact parents. Here we use cross-fostering methods to determine the mode of transmission of alloparental behavior and oxytocin receptor (OTR) and vasopressin V1a receptor (V1aR) binding from parent to offspring. Offspring were cross-fostered or in-fostered on postnatal day 1 and parental care received was quantified in the first week postpartum. At weaning, offspring underwent an alloparental care test and brains were then collected from all parents and offspring to examine OTR and V1aR binding. Results indicate that alloparental behavior of offspring was predicted by the parental behavior of their rearing parents. Receptor binding for both OTR and V1aR tended to be predicted by the genetic mothers for female offspring and by the genetic fathers for male offspring. These findings suggest a different, sex-dependent, role of early experience and genetics in shaping behavior compared to receptor distribution and support the notion of sex-dependent outcomes.

Social Role Specialization Promotes Cooperation between Parents

Biparental care of offspring is a widespread social behavior, and various ecological, life-history, and demographic factors have been proposed to explain its evolution and maintenance. Raising offspring generally requires several types of care (e.g., feeding, brooding, and defense), and males and females often specialize in providing different types of care. However, theoretical models of care often assume that care is a single variable and hence that a unit of care by the mother is interchangeable with a unit of care by the father. We hypothesize that the ability of one parent to provide all types of care may be limited by nonadditive costs or by sex-based asymmetries in the costs of particular care types. Using an individual-based simulation, we show that synergistic costs of investing in two tasks or negligible sex-based cost asymmetries select for task specialization and biparental care. Biparental care persists despite intense sexual selection and sex-biased mortality, suggesting that previous models make overly restrictive predictions of the conditions under which cooperation can be maintained. Our model provides a mechanistic underpinning for published models that show that the synergistic benefits of individuals cooperating can stabilize cooperation, both in the context of parental care and in other social scenarios.

How is sexual conflict over parental care resolved? A meta‐analysis

Biparental care of offspring is both a form of cooperation and a source of conflict. Parents face a trade-off between current and future reproduction: caring less for the current brood allows individuals to maintain energy reserves and increase their chances of remating. How can selection maintain biparental care, given this temptation to defect? The answer lies in how parents respond to changes in each other's effort. Game-theoretical models predict that biparental care is evolutionarily stable when reduced care by one parent leads its partner to increase care, but not so much that it completely compensates for the lost input. Experiments designed to reveal responses to reduced partner effort have mainly focused on birds. We present a meta-analysis of 54 such studies, and conclude that the mean response was indeed partial compensation. Males and females responded differently and this was in part mediated by the type of manipulation used.

The effects of lactation and infant care on adult energy budgets in wild siamangs (Symphalangus syndactylus)

In mammals with biparental care of offspring, males and females may bear substantial energetic costs of reproduction. Adult strategies to reduce energetic stress include changes in activity patterns, reduced basal metabolic rates, and storage of energy prior to a reproductive attempt. I quantified patterns of behavior in five groups of wild siamangs (Symphalangus syndactylus) to detect periods of high energetic investment by adults and to examine the relationships between infant care and adult activity patterns. For females, the estimated costs of lactation peaked at around infant age 4-6 months and were low by infant age 1 year, whereas the estimated costs of infant-carrying peaked between ages 7 and 12 months, and approached zero by age 16 months. There was a transition from primarily female to male care in the second year of life in some groups. Females spent significantly less time feeding during lactation than during the later stages of infant care, suggesting that female siamangs do not use increased food intake to offset the costs of lactation. Female feeding time was highest between infant ages 16 and 21 months, a period of relatively low female investment in the current offspring that coincided with the period of highest male investment in infant care. This suggests that male care may reduce the costs of infant care for females in the later stages of a reproductive attempt. The female energy gain resulting from male care was likely invested in somatic maintenance and future reproduction, rather than the current offspring.

Male provisioning is negatively correlated with attempted extrapair copulation frequency in the stitchbird (or hihi)

In species with biparental care of offspring and high levels of extrapair parentage, paired males may suffer reduced fitness by investing in offspring that are not their own. In such instances, males are predicted to evolve some form of discrimination between kin and nonkin and vary investment accordingly. One simple form of discrimination is to follow behavioural cues to paternity. We investigated paternal contribution to chick rearing in a socially monogamous population of stitchbirds, Notiomystis cincta, with high levels of extrapair copulation (EPC) and extrapair paternity. The relative contribution of the male to chick provisioning was negatively correlated with attempted EPC frequency. Because the majority of EPC attempts are forced and conspicuous in stitchbirds they are an obvious cue for males to use.