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Acker P, Burthe SJ, Newell MA, Grist H, Gunn C, Harris MP, Payo-Payo A, Swann R, Wanless S, Daunt F, Reid JM. Episodes of opposing survival and reproductive selection cause strong fluctuating selection on seasonal migration versus residence. Proc Biol Sci 2021; 288:20210404. [PMID: 34004132 PMCID: PMC8131125 DOI: 10.1098/rspb.2021.0404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/23/2021] [Indexed: 12/18/2022] Open
Abstract
Quantifying temporal variation in sex-specific selection on key ecologically relevant traits, and quantifying how such variation arises through synergistic or opposing components of survival and reproductive selection, is central to understanding eco-evolutionary dynamics, but rarely achieved. Seasonal migration versus residence is one key trait that directly shapes spatio-seasonal population dynamics in spatially and temporally varying environments, but temporal dynamics of sex-specific selection have not been fully quantified. We fitted multi-event capture-recapture models to year-round ring resightings and breeding success data from partially migratory European shags (Phalacrocorax aristotelis) to quantify temporal variation in annual sex-specific selection on seasonal migration versus residence arising through adult survival, reproduction and the combination of both (i.e. annual fitness). We demonstrate episodes of strong and strongly fluctuating selection through annual fitness that were broadly synchronized across females and males. These overall fluctuations arose because strong reproductive selection against migration in several years contrasted with strong survival selection against residence in years with extreme climatic events. These results indicate how substantial phenotypic and genetic variation in migration versus residence could be maintained, and highlight that biologically important fluctuations in selection may not be detected unless both survival selection and reproductive selection are appropriately quantified and combined.
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Affiliation(s)
- Paul Acker
- School of Biological Sciences, University of Aberdeen, UK
- Centre for Biodiversity Dynamics, Institutt for Biologi, NTNU, Norway
| | - Sarah J. Burthe
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
| | - Mark A. Newell
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
| | - Hannah Grist
- SAMS Research Services Ltd, European Marine Science Park, Oban, UK
| | - Carrie Gunn
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
| | | | - Ana Payo-Payo
- School of Biological Sciences, University of Aberdeen, UK
| | | | - Sarah Wanless
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
| | - Francis Daunt
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
| | - Jane M. Reid
- School of Biological Sciences, University of Aberdeen, UK
- Centre for Biodiversity Dynamics, Institutt for Biologi, NTNU, Norway
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Shaw AK, Craft ME, Zuk M, Binning SA. Host migration strategy is shaped by forms of parasite transmission and infection cost. J Anim Ecol 2019; 88:1601-1612. [PMID: 31220346 DOI: 10.1111/1365-2656.13050] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/10/2019] [Indexed: 01/01/2023]
Abstract
Most studies on the evolution of migration focus on food, mates and/or climate as factors influencing these movements, whereas negative species interactions such as predators, parasites and pathogens are often ignored. Although infection and its associated costs clearly have the potential to influence migration, thoroughly studying these interactions is challenging without a solid theoretical framework from which to develop testable predictions in natural systems. Here, we aim to understand when parasites favour the evolution of migration. We develop a general model which enables us to explore a broad range of biological conditions and to capture population and infection dynamics over both ecological and evolutionary time-scales. We show that when migration evolves depends on whether the costs of migration and infection are paid in reduced fecundity or survival. Also important are the parasite transmission mode and spatiotemporal dynamics of infection and recovery (if it occurs). Finally, we find that partial migration (where only a fraction of the population migrates) can evolve but only when parasite transmission is density-dependent. Our results highlight the critical, if overlooked, role of parasites in shaping long-distance movement patterns, and suggest that infection should be considered alongside more traditional drivers of migration in both empirical and theoretical studies.
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Affiliation(s)
- Allison K Shaw
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, Minnesota
| | - Marlene Zuk
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota
| | - Sandra A Binning
- Département de Sciences Biologiques, Université de Montréal, Montréal, Quebec, Canada
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3
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Grist H, Daunt F, Wanless S, Burthe SJ, Newell MA, Harris MP, Reid JM. Reproductive performance of resident and migrant males, females and pairs in a partially migratory bird. J Anim Ecol 2017; 86:1010-1021. [PMID: 28502109 PMCID: PMC6849534 DOI: 10.1111/1365-2656.12691] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/31/2017] [Indexed: 11/27/2022]
Abstract
Quantifying among‐individual variation in life‐history strategies, and associated variation in reproductive performance and resulting demographic structure, is key to understanding and predicting population dynamics and life‐history evolution. Partial migration, where populations comprise a mixture of resident and seasonally migrant individuals, constitutes a dimension of life‐history variation that could be associated with substantial variation in reproductive performance. However, such variation has rarely been quantified due to the challenge of measuring reproduction and migration across a sufficient number of seasonally mobile males and females. We used intensive winter (non‐breeding season) resightings of colour‐ringed adult European shags (Phalacrocorax aristotelis) from a known breeding colony to identify resident and migrant individuals. We tested whether two aspects of annual reproductive performance, brood hatch date and breeding success, differed between resident and migrant males, females and breeding pairs observed across three consecutive winters and breeding seasons. The sex ratios of observed resident and migrant shags did not significantly differ from each other or from 1:1, suggesting that both sexes are partially migratory and that migration was not sex‐biased across surveyed areas. Individual resident males and females hatched their broods 6 days earlier and fledged 0.2 more chicks per year than migrant males and females on average. Resident individuals of both sexes therefore had higher breeding success than migrants. Hatch date and breeding success also varied with a pair's joint migratory strategy such that resident–resident pairs hatched their broods 12 days earlier than migrant–migrant pairs, and fledged 0.7 more chicks per year on average. However, there was no evidence of assortative pairing with respect to migratory strategy: observed frequencies of migrant–migrant and resident–resident pairs did not differ from those expected given random pairing. These data demonstrate substantial variation in two key aspects of reproductive performance associated with the migratory strategies of males, females and breeding pairs within a partially migratory population. These patterns could reflect direct and/or indirect mechanisms, but imply that individual variation in migratory strategy and variation in pairing among residents and migrants could influence selection on migration and drive complex population and evolutionary dynamics.
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Affiliation(s)
- Hannah Grist
- Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, Aberdeen, UK.,Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK.,Scottish Ornithologists' Club, Waterston House, Aberlady, UK.,Scottish Association for Marine Science, Argyll, UK
| | - Francis Daunt
- Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK
| | - Sarah Wanless
- Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK
| | - Sarah J Burthe
- Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK
| | - Mark A Newell
- Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK
| | - Mike P Harris
- Centre for Ecology & Hydrology, Bush Estate, Midlothian, UK
| | - Jane M Reid
- Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, Aberdeen, UK
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Denoël M. On the identification of paedomorphic and overwintering larval newts based on cloacal shape: review and guidelines. Curr Zool 2017; 63:165-173. [PMID: 29491974 PMCID: PMC5804162 DOI: 10.1093/cz/zow054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/15/2016] [Indexed: 11/14/2022] Open
Abstract
Paedomorphosis is an alternative process to metamorphosis in which adults retain larval traits at the adult stage. It is frequent in newts and salamanders, where larvae reach sexual maturity without losing their gills. However, in some populations, larvae overwinter in water, while remaining immature. These alternative ontogenetic processes are of particular interest in various research fields, but have different causes and consequences, as only paedomorphosis allows metamorphosis to be bypassed before maturity. It is thus relevant to efficiently identify paedomorphs versus overwintering larvae. In this context, the aim of this article was 3-fold: firstly, to perform a meta-analysis of the identification procedures carried out in the literature; secondly, to determine the effectiveness of body size to make inferences about adulthood by surveying natural newt populations of Lissotriton helveticus and Ichthyosaura alpestris, and thirdly, to propose easy guidelines for an accurate distinction between large larvae and paedomorphs based on an external sexual trait, which is essential for reproduction-the cloaca. More than half of the studies in the literature do not mention the diagnostic criteria used for determining adulthood. The criteria mentioned were the presence of mature gonads (10%), eggs laid (4%), courtship behavior (10%), and external morphological sexual traits (39%) including the cloaca (24%). Body-size thresholds should not be used as a proxy for paedomorphosis, because overwintering larvae can reach a larger size than paedomorphs within the same populations. In contrast, diagnosis based on cloacal external morphology is recommended, as it can be processed by the rapid visual assessment of all caught specimens, thus providing straightforward data at the individual level for both sexes.
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Affiliation(s)
- Mathieu Denoël
- Laboratory of Fish and Amphibian Ethology, Behavioural Biology Unit, FOCUS, University of Liège, 22 Quai van Benden, 4020 Liège, Belgium
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Aspbury AS, Grayson KL, Fantaye S, Nichols I, Myers-Burton M, Ortiz-Mangual X, Gabor CR. The association between male-biased sex ratio and indicators of stress in red-spotted newts. Physiol Behav 2017; 173:156-162. [PMID: 28167148 DOI: 10.1016/j.physbeh.2017.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/28/2016] [Accepted: 02/02/2017] [Indexed: 11/24/2022]
Abstract
In populations with a male-biased operational sex ratio, coercive mating by males can have fitness consequences for females. One component of reduced fitness for females in populations with a male-biased OSR may be greater activation of the stress response, resulting in higher corticosterone release rates (CORT; a glucocorticoid stress hormone in amphibians). We test the hypothesis that a male-biased sex ratio affects female activity and release rates of CORT and testosterone (T) in male and female red-spotted newts (Notophthalmus viridescens). First, we evaluated if chemical cues from a male-biased sex ratio affect activity and CORT release rates in females. We predicted that females exposed to chemical cues of three males would be less active and have higher CORT release rates than those exposed to chemical cues of one male. Second, we measured CORT release rates of red-spotted newts in field enclosures with either a male-biased or a female-biased sex ratio. We predicted that females in the male-biased treatment would have higher CORT and T release rates than those in a female-biased treatment, owing to higher levels of male harassment. We also predicted that males would have higher CORT and T release rates in male-biased treatments due to higher levels of male-male competition. Females were not less active in response to chemical cues from more males over fewer males, but there was a positive relationship between female activity and CORT when they were exposed to the cues of three males. We also found that females, but not males, in the male-biased sex ratio treatment had higher CORT and T release rates than those in the female-biased treatment. Our results support the hypothesis that a male-biased sex ratio leads to a higher stress response, which may underlie the observed decrease in immune function and body condition in previous work exposing female red-spotted newts to a male-biased sex ratio. This study furthers our understanding of the mechanistic basis for costs associated with a male-biased sex ratio in a pond-breeding amphibian.
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Affiliation(s)
- Andrea S Aspbury
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666-4684, USA; Mountain Lake Biological Station, 240 Salt Pond Road, Pembroke, VA 24136, USA.
| | - Kristine L Grayson
- Mountain Lake Biological Station, 240 Salt Pond Road, Pembroke, VA 24136, USA; Department of Biology, University of Richmond, 28 Westhampton Way, Richmond, VA, 23173, USA
| | - Selamawit Fantaye
- Mountain Lake Biological Station, 240 Salt Pond Road, Pembroke, VA 24136, USA
| | - Ian Nichols
- Mountain Lake Biological Station, 240 Salt Pond Road, Pembroke, VA 24136, USA
| | | | | | - Caitlin R Gabor
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666-4684, USA; Mountain Lake Biological Station, 240 Salt Pond Road, Pembroke, VA 24136, USA
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Green DJ, Whitehorne IBJ, Middleton HA, Morrissey CA. Do American dippers obtain a survival benefit from altitudinal migration? PLoS One 2015; 10:e0125734. [PMID: 25905712 PMCID: PMC4408061 DOI: 10.1371/journal.pone.0125734] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/25/2015] [Indexed: 11/18/2022] Open
Abstract
Studies of partial migrants provide an opportunity to assess the cost and benefits of migration. Previous work has demonstrated that sedentary American dippers (residents) have higher annual productivity than altitudinal migrants that move to higher elevations to breed. Here we use a ten-year (30 period) mark-recapture dataset to evaluate whether migrants offset their lower productivity with higher survival during the migration-breeding period when they occupy different habitat, or early and late-winter periods when they coexist with residents. Mark-recapture models provide no evidence that apparent monthly survival of migrants is higher than that of residents at any time of the year. The best-supported model suggests that monthly survival is higher in the migration-breeding period than winter periods. Another well-supported model suggested that residency conferred a survival benefit, and annual apparent survival (calculated from model weighted monthly apparent survival estimates using the Delta method) of residents (0.511 ± 0.038SE) was slightly higher than that of migrants (0.487 ± 0.032). Winter survival of American dippers was influenced by environmental conditions; monthly apparent survival increased as maximum daily flow rates increased and declined as winter temperatures became colder. However, we found no evidence that environmental conditions altered differences in winter survival of residents and migrants. Since migratory American dippers have lower productivity and slightly lower survival than residents our data suggests that partial migration is likely an outcome of competition for limited nest sites at low elevations, with less competitive individuals being forced to migrate to higher elevations in order to breed.
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Affiliation(s)
- David J. Green
- Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ivy B. J. Whitehorne
- Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Holly A. Middleton
- Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Christy A. Morrissey
- Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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De Lisle SP, Rowe L. Parasitism and the expression of sexual dimorphism. Ecol Evol 2015; 5:961-7. [PMID: 25750721 PMCID: PMC4338977 DOI: 10.1002/ece3.1416] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/05/2015] [Accepted: 01/12/2015] [Indexed: 11/12/2022] Open
Abstract
Although a negative covariance between parasite load and sexually selected trait expression is a requirement of few sexual selection models, such a covariance may be a general result of life-history allocation trade-offs. If both allocation to sexually selected traits and to somatic maintenance (immunocompetence) are condition dependent, then in populations where individuals vary in condition, a positive covariance between trait expression and immunocompetence, and thus a negative covariance between trait and parasite load, is expected. We test the prediction that parasite load is generally related to the expression of sexual dimorphism across two breeding seasons in a wild salamander population and show that males have higher trematode parasite loads for their body size than females and that a key sexually selected trait covaries negatively with parasite load in males. We found evidence of a weaker negative relationship between the analogous female trait and parasite infection. These results underscore that parasite infection may covary with expression of sexually selected traits, both within and among species, regardless of the model of sexual selection, and also suggest that the evolution of condition dependence in males may affect the evolution of female trait expression.
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Affiliation(s)
- Stephen P De Lisle
- Department of Ecology and Evolutionary Biology, University of TorontoToronto, Ontario, Canada
| | - Locke Rowe
- Department of Ecology and Evolutionary Biology, University of TorontoToronto, Ontario, Canada
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De Lisle SP, Rowe L. Interactive effects of competition and social environment on the expression of sexual dimorphism. J Evol Biol 2014; 27:1069-77. [DOI: 10.1111/jeb.12381] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 02/27/2014] [Accepted: 03/23/2014] [Indexed: 11/30/2022]
Affiliation(s)
- S. P. De Lisle
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto ON Canada
| | - L. Rowe
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto ON Canada
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9
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Grayson KL, De Lisle SP, Jackson JE, Black SJ, Crespi EJ. Behavioral and physiological female responses to male sex ratio bias in a pond-breeding amphibian. Front Zool 2012; 9:24. [PMID: 22988835 PMCID: PMC3478290 DOI: 10.1186/1742-9994-9-24] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/03/2012] [Indexed: 11/18/2022] Open
Abstract
Introduction The phenomenon of sexual conflict has been well documented, and in populations with biased operational sex ratios the consequences for the rarer sex can be severe. Females are typically a limited resource and males often evolve aggressive mating behaviors, which can improve individual fitness for the male while negatively impacting female condition and fitness. In response, females can adjust their behavior to minimize exposure to aggressive mating tactics or minimize the costs of mating harassment. While male-male competition is common in amphibian mating systems, little is known about the consequences or responses of females. The red-spotted newt (Notophthalmus viridescens) is a common pond-breeding amphibian with a complex, well-studied mating system where males aggressively court females. Breeding populations across much of its range have male-biased sex ratios and we predicted that female newts would have behavioral mechanisms to mitigate mating pressure from males. We conducted four experiments examining the costs and behavioral responses of female N. viridescens exposed to a male-biased environment. Results In field enclosures, we found that female newts exposed to a male-biased environment during the five-month breeding season ended with lower body condition compared to those in a female-biased environment. Shorter-term exposure to a male-biased environment for five weeks caused a decrease in circulating total leukocyte and lymphocyte abundance in blood, which suggests females experienced physiological stress. In behavioral experiments, we found that females were more agitated in the presence of male chemical cues and females in a male-biased environment spent more time in refuge than those in a female-biased environment. Conclusions Our results indicate that male-biased conditions can incur costs to females of decreased condition and potentially increased risk of infection. However, we found that females can also alter their behavior and microhabitat use under a male-biased sex ratio. Consistent with surveys showing reduced detection probabilities for females, our research suggests that females avoid male encounters using edge and substrate habitat. Our work illustrates the integrated suite of impacts that sexual conflict can have on the structure and ecology of a population.
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Affiliation(s)
- Kristine L Grayson
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA.
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Grayson KL, Bailey LL, Wilbur HM. Life history benefits of residency in a partially migrating pond-breeding amphibian. Ecology 2011; 92:1236-46. [DOI: 10.1890/11-0133.1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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