Coevolution of female fidelity and male help in populations with alternative reproductive tactics

In socially monogamous species, pair-bonded males often continue to provide care to all offspring in their nests despite some degree of paternity loss due to female extra-pair copulation. Previous theoretical models suggested that females can use their within-pair offspring as ‘hostages' to blackmail their social mates, so that they continue to provide care to the brood at low levels of cuckoldry. These models, however, rely on the assumption of sufficiently accurate male detection of cuckoldry and the reduction of parental effort in case of suspicion. Therefore, they cannot explain the abundant cases where cuckolded males continue to provide extensive care to the brood. Here we use an analytical population genetics model and an individual-based simulation model to explore the coevolution of female fidelity and male help in populations with two genetically determined alternative reproductive tactics (ARTs): sneakers that achieve paternity solely via extra-pair copulations and bourgeois that form a mating pair and spend some efforts in brood care. We show that when the efficiency of mate guarding is intermediate, the bourgeois males can evolve to ‘specialize' in providing care by spending more than 90% of time in helping their females while guarding them as much as possible, despite frequent cuckoldry by the sneakers. We also show that when sneakers have tactic-specific adaptations and thus are more competitive than the bourgeois in gaining extra-pair fertilizations, the frequency of sneakers and the degrees of female fidelity and male help can fluctuate in evolutionary cycles. Our theoretical predictions highlight the need for further empirical tests in species with ARTs.

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Genetic correlations across genetically determined and developmentally plastic alternative reproductive tactics

10.1101/768721 ◽

2019 ◽

Author(s):

Jessica K. Abbott ◽

Oscar Rios-Cardenas ◽

Molly Morris

Keyword(s):

Body Size ◽

Genetic Correlation ◽

Genetic Correlations ◽

Phenotypic Expression ◽

Alternative Reproductive Tactics ◽

Phenotypic Trait ◽

Sexual Antagonism ◽

Reproductive Tactics ◽

Genetic Conflict ◽

Genetically Determined

AbstractAlternative reproductive tactics occur when individuals of the same sex have a suite of morphological and/or behavioural traits that allow them to pursue different reproductive strategies. A common pattern is e.g. the existence of “courter” and “sneaker” tactics within males. We have previously argued that alternative reproductive tactics should be subject to genetic conflict over the phenotypic expression of traits, similar to sexual antagonism. In this process, which we called intra-locus tactical conflict, genetically determined tactics experience conflicting selection on a shared phenotypic trait, such as body size, but a positive genetic correlation between tactics in body size prevents either tactic from reaching its optimum. Recently, other authors have attempted to extend this idea to developmentally plastic alternative reproductive tactics, with mixed results. However, it is not clear whether we should expect intra-locus tactical conflict in developmentally plastic tactics or not. We have therefore run a series of simulation models investigating under what conditions we should expect to see positive estimates of the inter-tactical genetic correlation, since a positive genetic correlation is a prerequisite for the existence of intra-locus tactical conflict. We found that for autosomal, X-linked, and Y-linked genetically-determined tactics, estimated inter-tactical genetic correlations were generally high. However, for developmentally plastic tactics, the genetic correlation depends on the properties of the switching threshold between tactics. If it is fixed, then estimated genetic correlations are positive, but if there is genetic variation in the switch-point, then any sign and magnitude of estimated genetic correlation is possible, even for highly heritable traits where the true underlying correlation is perfect. This means that caution should be used when investigating genetic constraints in plastic phenotypes.

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The evolution of genetic and conditional alternative reproductive tactics

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.2945 ◽

2016 ◽

Vol 283 (1825) ◽

pp. 20152945 ◽

Cited By ~ 27

Author(s):

Leif Engqvist ◽

Michael Taborsky

Keyword(s):

Body Size ◽

Size Variation ◽

Alternative Reproductive Tactics ◽

Disruptive Selection ◽

Relevant Parameter ◽

Reproductive Tactics ◽

Adaptive Diversification ◽

Size Dependent ◽

Mortality Causes ◽

Genetically Determined

Frequency-dependent selection may drive adaptive diversification within species. It is yet unclear why the occurrence of alternative reproductive tactics (ARTs) is highly divergent between major animal taxa. Here we aim to clarify the environmental and social conditions favouring the evolution of intra-population variance of male reproductive phenotypes. Our results suggest that genetically determined ARTs that are fixed for life evolve when there is strong selection on body size due to size-dependent competitiveness, in combination with environmental factors reducing size benefits. The latter may result from growth costs or, more generally, from age-dependent but size-independent mortality causes. This generates disruptive selection on growth trajectories underlying tactic choice. In many parameter settings, the model also predicts ARTs to evolve that are flexible and responsive to current conditions. Interestingly, the conditions favouring the evolution of flexible tactics diverge considerably from those favouring genetic variability. Nevertheless, in a restricted but relevant parameter space, our model predicts the simultaneous emergence and maintenance of a mixture of multiple tactics, both genetically and conditionally determined. Important conditions for the emergence of ARTs include size variation of competitors, which is inherently greater in species with indeterminate growth than in taxa reproducing only after reaching their terminal body size. This is probably the reason why ARTs are more common in fishes than in other major taxa.

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Breeding patterns of female prairie voles (Microtus ochrogaster) displaying alternative reproductive tactics

Journal of Mammalogy ◽

10.1093/jmammal/gyaa058 ◽

2020 ◽

Vol 101 (4) ◽

pp. 990-999

Author(s):

James B Lichter ◽

Connor T Lambert ◽

Nancy G Solomon ◽

Brian Keane

Keyword(s):

Multiple Paternity ◽

Mate Guarding ◽

Alternative Reproductive Tactics ◽

Microtus Ochrogaster ◽

Social Partner ◽

Prairie Voles ◽

Reproductive Tactics ◽

Resident Male ◽

Primary Determinant ◽

Alternative Behaviors

Abstract Individuals of either sex may display alternative behaviors to obtain copulations, but few studies have examined the breeding patterns of females and males in populations where individuals of both sexes exhibit alternative reproductive tactics (ARTs). In prairie voles (Microtus ochrogaster), most adults are territorial, residing at a single nest site either as male–female pairs or as solitary individuals. However, some adults adopt nonterritorial, wandering tactics. During two field seasons monitoring prairie vole populations maintained in seminatural enclosures, we found evidence that females exhibiting different ARTs bred differentially with resident and wandering males. Females residing at a nest with a male bred significantly more often with a paired resident male, primarily their social partner, and significantly less often with male wanderers compared to single resident females or wandering females. These patterns were not due to chance, because paired resident females produced offspring with paired resident males significantly more than expected based on the relative abundance of these males in the population, whereas single resident females produced offspring with male wanderers significantly more than expected based on the proportion of male wanderers in the population. We did not find any evidence that multiple paternity was greater in the litters of single resident females and wanderer females even though these females lacked a male social partner to limit mating access by multiple males. This suggests that mate guarding by a female’s male social partner was not the primary determinant of multiple paternity in the litters of females exhibiting different reproductive tactics. However, male ART did affect the likelihood of multiple paternity. Females that produced offspring with single resident or wanderer males had an increased likelihood of multiple paternity relative to females producing offspring with paired resident males. The results of this study show that female and male ARTs can affect breeding patterns.

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Mate guarding and alternative reproductive tactics in the ant Hypoponera opacior

Animal Behaviour ◽

10.1006/anbe.2001.1945 ◽

2002 ◽

Vol 63 (3) ◽

pp. 597-604 ◽

Cited By ~ 24

Author(s):

Susanne Foitzik ◽

Jürgen Heinze ◽

Björn Oberstadt ◽

Joan M. Herbers

Keyword(s):

Mate Guarding ◽

Alternative Reproductive Tactics ◽

Reproductive Tactics

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Report of an extra-pair copulation in the Rufous Hornero, Furnarius rufus (Aves: Furnariidae)

Papéis Avulsos de Zoologia ◽

10.11606/1807-0205/2021.61.67 ◽

2021 ◽

Vol 61 ◽

pp. e20216167

Author(s):

Pedro Diniz ◽

Carlos Biagolini-Jr.

Keyword(s):

Food Access ◽

Mate Guarding ◽

Breeding Biology ◽

Territorial Male ◽

Aggressive Interaction ◽

Extra Pair Paternity ◽

Monogamous Species ◽

Bird Breeding ◽

Socially Monogamous ◽

Low Levels

In the last decade, studies in bird breeding biology have shown that infidelity is prevalent in socially monogamous species. Here, we describe an extra-pair copulation (EPC) event in the Rufous Hornero (Furnarius rufus), a socially monogamous bird with year-round territoriality and low levels of extra-pair paternity. Before the EPC, a within-pair copulation (WPC) occurred inside the pair’s territory. The WPC occurred on the ground and between a banded male (ca. 6 years-old) and an unbanded female. Ten minutes later this breeding pair invaded a neighboring territory, presumably to forage. The territorial male was chased back to its territory by an unbanded male neighbor after being detected. The male neighbor was paired with an unbanded female that did not participate in the aggressive interaction. When flying back to its territory the male neighbor copulated with the territorial female on the ground (ie. EPC). The territorial male flew, vocalized, and perched above the male neighbor, interrupting the EPC. The aggressive interaction then ceased as each pair resumed foraging in their respective territories. These observations suggest that Rufous Horneros can use EPC to obtain immediate benefits (food access in a neighbor’s territory). Moreover, WPC may be detected by neighbors and physical mate guarding and/or frequent WPC may be necessary to prevent EPC in the Rufous Hornero.

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