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Macedo-Rego RC, Jennions MD, Santos ESA. Does the potential strength of sexual selection differ between mating systems with and without defensive behaviours? A meta-analysis. Biol Rev Camb Philos Soc 2024; 99:1504-1523. [PMID: 38597347 DOI: 10.1111/brv.13078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/11/2024]
Abstract
The Darwin-Bateman paradigm predicts that females enhance their fitness by being choosy and mating with high-quality males, while males should compete to mate with as many females as possible. In many species, males enhance their fitness by defending females and/or resources used by females. That is, males directly defend access to mating opportunities. However, paternity analyses have repeatedly shown that females in most species mate polyandrously, which contradicts traditional expectations that male defensive behaviours lead to monandry. Here, in an extensive meta-analysis, encompassing 109 species and 1026 effect sizes from across the animal kingdom, we tested if the occurrence of defensive behaviours modulates sexual selection on females and males. If so, we can illuminate the extent to which males really succeed in defending access to mating and fertilisation opportunities. We used four different indices of the opportunity for sexual selection that comprise pre-mating and/or post-mating episodes of selection. We found, for both sexes, that the occurrence of defensive behaviours does not modulate the potential strength of sexual selection. This implies that male defensive behaviours do not predict the true intensity of sexual selection. While the most extreme levels of sexual selection on males are in species with male defensive behaviours, which indicates that males do sometimes succeed in restricting females' re-mating ability (e.g. elephant seals, Mirounga leonina), estimates of the opportunity for sexual selection vary greatly across species, regardless of whether or not defensive behaviours occur. Indeed, widespread polyandry shows that females are usually not restricted by male defensive behaviours. In addition, our results indicate that post-mating episodes of selection, such as cryptic female choice and sperm competition, might be important factors modulating the opportunity for sexual selection. We discuss: (i) why male defensive behaviours fail to lower the opportunity for sexual selection among females or fail to elevate it for males; (ii) how post-mating events might influence sexual selection; and (iii) the role of females as active participants in sexual selection. We also highlight that inadequate data reporting in the literature prevented us from extracting effect sizes from many studies that had presumably collected the relevant data.
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Affiliation(s)
- Renato C Macedo-Rego
- Programa de Pós-graduação em Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, no. 321, São Paulo, SP 05508-090, Brazil
- Division of Ecology & Evolution, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Michael D Jennions
- Division of Ecology & Evolution, Research School of Biology, Australian National University, Canberra, ACT, Australia
- Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Centre, 10 Marais Street, Stellenbosch, 7600, South Africa
| | - Eduardo S A Santos
- Programa de Pós-graduação em Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, no. 321, São Paulo, SP 05508-090, Brazil
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Pärssinen V, Simmons LW, Kvarnemo C. Mating competition among females: testing the distinction between natural and sexual selection in an insect. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240191. [PMID: 38586425 PMCID: PMC10999239 DOI: 10.1098/rsos.240191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/10/2024] [Indexed: 04/09/2024]
Abstract
In species where females compete for mates, the male often provides the female with resources in addition to gametes. A recently suggested definition of sexual selection proposed that if females only benefit from additional resources that come with each mating and not additional gametes, female intrasexual competition for mating opportunities would result in natural selection rather than sexual selection. The nuptial gift-giving bushcricket Kawanaphila nartee has dynamic sex roles and has been a textbook example of sexual selection acting on females via mating competition. We investigated whether females of this species gain fitness benefits from nuptial gifts, additional ejaculates or both by controlling the number of matings and whether the female was allowed to consume the nutritious gift (spermatophylax) at mating. We found that egg production per day of life increased with the number of additional matings, both with and without spermatophylax consumption, but consuming the spermatophylax had an additional positive effect on the number of eggs. These effects were particularly strong in females with shorter lifespans. We discuss how the recently suggested definition of sexual selection applies to nuptial-feeding insects and conclude that both natural and sexual selections influence mating competition in K. nartee females.
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Affiliation(s)
- Varpu Pärssinen
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg40530, Sweden
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley6009, Australia
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg40530, Sweden
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Albo MJ, Pavón-Peláez C, Villar MM, Buzatto BA, Tomasco I. Stressful environments favor deceptive alternative mating tactics to become dominant. BMC Biol 2023; 21:162. [PMID: 37501205 PMCID: PMC10375696 DOI: 10.1186/s12915-023-01664-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND Deceptive alternative mating tactics are commonly maintained at low frequencies within populations because males using them are less competitive and acquire lower fitness than those using dominant tactics. However, the successful invasion of a male deceptive tactic is plausible if deception carries no fitness cost to females. Among populations of the gift-giving spider Paratrechalea ornata, males very often offer females a deceptive worthless gift, rather than a nutritive gift. We tested the degree to which deceptive worthless gifts can occur in natural populations living under divergent environmental conditions (moderate and stressful). We examined the plasticity of morphological and behavioral traits and analyzed the fitness of females in relation to the gift type, also examining the paternity acquired by males offering either gift type. RESULTS We demonstrated that worthless gifts can become dominant under highly stressful environmental conditions (84-100%). Individuals in such environment reach smaller sizes than those in moderate conditions. We suggest that the size reduction probably favors low metabolic demands in both sexes and may reduce the costs associated with receiving deceptive worthless gifts for females. In contrast, males living under moderate conditions varied the use of the deceptive tactic (0-95%), and worthless gifts negatively influenced female fecundity. Furthermore, male size, rather than gift content, positively impacted paternity success in the moderate but not in the stressful environment. CONCLUSIONS Overall, this is the first empirical evidence that a reversible deceptive tactic can become dominant when the environment becomes harsh and mate choice becomes limited.
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Affiliation(s)
- Maria J Albo
- Sección Entomología, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay.
- Departamento de Ecología y Biología Evolutiva, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
- Programa de Desarrollo de las Ciencias Básicas (PEDECIBA), Universidad de La República, Montevideo, Uruguay.
| | - Camila Pavón-Peláez
- Sección Entomología, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay
- Programa de Desarrollo de las Ciencias Básicas (PEDECIBA), Universidad de La República, Montevideo, Uruguay
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay
| | - Mauro Martínez Villar
- Sección Entomología, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay
- Programa de Desarrollo de las Ciencias Básicas (PEDECIBA), Universidad de La República, Montevideo, Uruguay
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay
| | - Bruno A Buzatto
- Flinders University, Adelaide, Australia
- Macquarie University, Sydney, Australia
| | - Ivanna Tomasco
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de La República, Montevideo, Uruguay
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Pavón-Peláez C, Franco-Trecu V, Pandulli-Alonso I, Jones TM, Albo MJ. Beyond the prey: male spiders highly invest in silk when producing worthless gifts. PeerJ 2022; 10:e12757. [PMID: 35036108 PMCID: PMC8742539 DOI: 10.7717/peerj.12757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/16/2021] [Indexed: 01/07/2023] Open
Abstract
In the spider Paratrechalea ornata, males have two gift-giving mating tactics, offering either a nutritive (prey) or a worthless (prey leftovers) silk wrapped gift to females. Both gift types confer similar mating success and duration and afford males a higher success rate than when they offer no gift. If this lack of difference in the reproductive benefits is true, we would expect all males to offer a gift but some males to offer a worthless gift even if prey are available. To test this, we allowed 18 males to court multiple females over five consecutive trials. In each trial, a male was able to produce a nutritive gift (a live housefly) or a worthless gift (mealworm exuviae). We found that, in line with our predictions, 20% of the males produced worthless gifts even when they had the opportunity to produce a nutritive one. However, rather than worthless gifts being a cheap tactic, they were related to a higher investment in silk wrapping. This latter result was replicated for worthless gifts produced in both the presence and absence of a live prey item. We propose that variation in gift-giving tactics likely evolved initially as a conditional strategy related to prey availability and male condition in P. ornata. Selection may then have favoured silk wrapping as a trait involved in female attraction, leading worthless gift-giving to invade.
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Affiliation(s)
- Camila Pavón-Peláez
- Programa de Desarrollo de las Ciencias Básicas (PEDECIBA), Universidad de la República, Uruguay,Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Valentina Franco-Trecu
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Irene Pandulli-Alonso
- Departamento de Ecología y Biología Evolutiva, Instittuto de investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Therésa M. Jones
- School of BioSciences, The University of Melbourne, 3010 Victoria, Australia
| | - Maria J. Albo
- Departamento de Ecología y Biología Evolutiva, Instittuto de investigaciones Biológicas Clemente Estable, Montevideo, Uruguay,Sección Entomología, Facultad de Ciencias, Universidad de la República, Uruguay
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Pandulli‐Alonso I, Tomasco IH, Albo MJ. The handsome liar: Male spiders offering worthless gifts can benefit increasing mating duration. Ethology 2021. [DOI: 10.1111/eth.13258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Irene Pandulli‐Alonso
- Departamento de Ecología y Biología Evolutiva Instituto de Investigaciones Biológicas Clemente Estable Montevideo Uruguay
| | - Ivanna H. Tomasco
- Departamento de Ecología y Evolución. Facultad de Ciencias Universidad de la República Montevideo Uruguay
| | - Maria J. Albo
- Departamento de Ecología y Biología Evolutiva Instituto de Investigaciones Biológicas Clemente Estable Montevideo Uruguay
- Departamento de Ecología y Evolución. Facultad de Ciencias Universidad de la República Montevideo Uruguay
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Macedo‐Rego RC, Costa‐Schmidt LE, Machado G. Males of a Neotropical spider adjust prey‐gift construction but not mate search in response to sperm competition. Ethology 2021. [DOI: 10.1111/eth.13202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Renato C. Macedo‐Rego
- Programa de Pós‐graduação em Ecologia Instituto de Biociências Universidade de São Paulo São Paulo Brazil
- LAGE do Departamento de Ecologia Instituto de Biociências Universidade de São Paulo São Paulo Brazil
| | - Luiz Ernesto Costa‐Schmidt
- LAGE do Departamento de Ecologia Instituto de Biociências Universidade de São Paulo São Paulo Brazil
- Departamento de Ecologia, Zoologia e Genética Instituto de Biologia Universidade Federal de Pelotas Pelotas Brazil
| | - Glauco Machado
- LAGE do Departamento de Ecologia Instituto de Biociências Universidade de São Paulo São Paulo Brazil
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Differential allocation in a gift-giving spider: males adjust their reproductive investment in response to female condition. BMC Ecol Evol 2021; 21:140. [PMID: 34238218 PMCID: PMC8268551 DOI: 10.1186/s12862-021-01870-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/25/2021] [Indexed: 11/24/2022] Open
Abstract
Background When males are selective, they can either reject low-quality females or adjust their reproductive investment in response to traits that indicate female quality (e.g., body size or condition). According to the differential allocation hypothesis, males increase their reproductive investment when paired with high-quality females (positive differential allocation) or increase their reproductive investment when paired with low-quality females (negative differential allocation). This hypothesis has been proposed for monogamous species with biparental care, and most empirical studies focus on birds. Here we used the polygamous spider Paratrechalea ornata, in which males offer prey wrapped in silk as nuptial gifts, to test whether males adjust their reproductive investment in gift size, pre-copulatory and copulatory courtship, and sperm transfer in response to female body condition. Results Males exposed to females in good body condition added more flies to the gift, stimulated these females longer with abdominal touches during pre-copulatory courtship, and had longer pedipalp insertions than males exposed to females in poor body condition. Female condition affected neither silk investment in nuptial gift wrapping nor the quantity of sperm transferred by males. Finally, females in good body condition oviposited faster after copulation and laid more eggs than females in poor body condition. Conclusions We provide experimental evidence that males of a gift-giving spider exhibit positive differential allocation in three key aspects of their reproductive investment: the size of the nutritious gift, duration of pre-copulatory courtship, and duration of pedipalp insertions, which is regarded as a form of copulatory courtship in spiders. This positive differential allocation is likely associated with the benefits of copulating with females in good body condition. These females are more fecund and oviposit faster after copulation than females in poor body condition, which under natural field conditions probably reduces the risk of multiple matings and thus the level of sperm competition faced by the males. As a final remark, our findings indicate that the hypothesis of differential allocation also applies to species with a scramble competition mating system, in which males heavily invest in nuptial gift construction, but not in parental care. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01870-1.
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Martínez Villar M, Trillo MC, Albo MJ. Ineffective nuptial gifts suggest female emancipation from sensory exploitation. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-02994-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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