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Baldwin K. "You feel like you're fairly disadvantaged with an advert over your head saying 'in final years of reproduction'": social egg freezing, dating and the (unequal) politics of reproductive ageing. Cult Health Sex 2024:1-15. [PMID: 38739479 DOI: 10.1080/13691058.2024.2341852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 04/08/2024] [Indexed: 05/16/2024]
Abstract
Recent decades have seen an increasing gap occurring between the 'desired' and 'actual' family size of middle-class and professional women. This situation of 'unrealised fertility' and 'incomplete families' carries implications at a population, but also couple and individual level. This paper explores how middle-class professional women make decisions about partnering and parenthood and how these are shaped by a contemporary neoliberal feminist discourse which articulates the possibility of 'having it all' through engagement in careful life planning, appropriate self-investment, and by drawing on new technologies of reproductive biomedicine. Informed by semi-structured interviews with UK and US women conducted at two different points in time, it explores how they approach and experience the process of relationship formation in the face of age-related fertility decline. It also examines how the use of social egg freezing shape their romantic and family building expectations but also their interactions with (potential) partners. In doing so, it explores how gendered cultural dating scripts and unequal gender power relations shape the formation and progression of intimate relationships in a manner which can disempower women as they age. It therefore questions whether egg freezing may be the 'great equaliser' that some have hoped.
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Affiliation(s)
- Kylie Baldwin
- Centre for Reproduction Research, Faculty of Health and Life Sciences, De Montfort University, Leicester, UK
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2
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Verghote K, Neeser N, Pennings G, Elger B, Provoost V. "It was not an accident": Women's experiences of renewing motherhood at 40. J Women Aging 2024; 36:181-196. [PMID: 38009748 DOI: 10.1080/08952841.2023.2286835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 11/20/2023] [Indexed: 11/29/2023]
Abstract
In recent decades, there has been an increase in motherhood at an advanced age that has raised several medical and social concerns. We conducted a qualitative interview study, guided by Interpretative Phenomenological Analysis, to focus on the motivations and experiences of Belgian women who 'renewed' their motherhood later in life, meaning they had one or several children and then (at least 10 years later) had another child at the age of 40 or older. We focused on ten women's experiences of motherhood later in life, as well as on the way they managed social norms and expectations regarding family building and the appropriate life course. We identified two main themes. The first theme describes the participants' encounters with social norms that challenged their decision to reproduce and parent later in life, and how they managed and anticipated criticism, surprise, disbelief and incomprehension about their renewed motherhood in various ways. The second theme shows how these women talked about taking responsibility as a (renewed) mother of advanced age. For them, responsible motherhood involved making thoughtful reproductive choices, attending to the range of needs of their children, and making extra efforts to safeguard the social and emotional wellbeing of their youngest children, thereby seeking to reduce potential harm resulting from these reproductive choices. This study provides insight into these women's self-conception and their interactions with prejudiced social views of motherhood and family building.
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Affiliation(s)
- Kato Verghote
- Bioethics Institute Ghent; Department of Philosophy and Moral Sciences, Ghent University, Ghent, Belgium
| | - Nathalie Neeser
- Institute for Biomedical Ethics, University of Basel, Basel, Switzerland
| | - Guido Pennings
- Bioethics Institute Ghent; Department of Philosophy and Moral Sciences, Ghent University, Ghent, Belgium
| | - Bernice Elger
- Institute for Biomedical Ethics, University of Basel, Basel, Switzerland
| | - Veerle Provoost
- Bioethics Institute Ghent; Department of Philosophy and Moral Sciences, Ghent University, Ghent, Belgium
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3
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Ding W, Xu Y, Kondracki AJ, Sun Y. Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis. Am J Obstet Gynecol 2024; 230:315-329.e31. [PMID: 37820985 DOI: 10.1016/j.ajog.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
OBJECTIVE Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events. DATA SOURCES PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022. STUDY ELIGIBILITY CRITERIA Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English. METHODS Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity. RESULTS In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance. CONCLUSION The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.
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Affiliation(s)
- Wenqin Ding
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, China
| | - Yuxiang Xu
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, China
| | - Anthony J Kondracki
- Department of Community Medicine, Mercer University School of Medicine, Macon, GA
| | - Ying Sun
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, China; Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, China; Anhui Provincial Key Laboratory of Population Health and Aristogenics, Anhui Medical University, Hefei, China.
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Sunga J, Humber J, Broders H. Individual Variation in Parturition Timing within and among Years for a Bat Maternity Colony. Front Biosci (Schol Ed) 2023; 15:8. [PMID: 37401508 DOI: 10.31083/j.fbs1502008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/23/2023] [Accepted: 06/07/2023] [Indexed: 07/05/2023]
Abstract
BACKGROUND In monoestrous species, the timing of reproduction can have important impacts on offspring survival. For heterotherms in temperate areas, parturition timing is constrained by cold weather survival strategies, such as hibernation and torpor. Female bats that are year-round residents of temperate regions, such as little brown myotis (Myotis lucifugus), invest significantly in parental care resulting in sharp changes in behavior immediately following parturition. These behavior changes may include increases in nighttime roost revisits, which can be used to identify parturition dates for individual bats that have been passive integrated transponder (PIT) tagged and use monitored roosts. METHODS Using a system of tagged bats and monitored roosts in Pynn's Brook and Salmonier Nature Park Newfoundland, Canada, we estimated parturition dates for 426 female M. lucifugus in at least one year, based on changes in nighttime roost revisit patterns, and quantified the variation in parturition dates within years among individuals, and within individuals among years. RESULTS Overall, we report on a wide variation in parturition dates within years among individuals as well as year-to-year variations, both across the population and within individuals. Spring weather conditions appeared to be important influences on parturition timing. CONCLUSIONS Changes in spring and summer temperature and extreme weather events, as expected due to ongoing climate change, may impact parturition timing, and therefore, offspring survival of temperate bats.
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Affiliation(s)
- Julia Sunga
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jessica Humber
- Department of Fisheries, Forestry and Agriculture, Government of Newfoundland and Labrador, Corner Brook, NL A2H 7S1, Canada
| | - Hugh Broders
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Biology, Saint Mary's University, Halifax, NS B3H 3C3, Canada
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Yuan J, Yu Y, Liu D, Sun Y. Associations between distinct dimensions of early life adversity and accelerated reproductive strategy among middle-aged women in China. Am J Obstet Gynecol 2022; 226:104.e1-104.e14. [PMID: 34384774 DOI: 10.1016/j.ajog.2021.07.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/21/2021] [Accepted: 07/27/2021] [Indexed: 11/01/2022]
Abstract
BACKGROUND Life history theory argues that unpredictable and harsh conditions such as early life adversity tends to produce a fast life history strategy, characterized by early sexual maturation and less parenting of offspring. It remains unclear whether all forms of early life adversity are associated with accelerated reproductive strategy, and most previous studies predominantly focused on single form of reproductive strategy indicators. OBJECTIVE To examine the associations between 2 distinct dimensions of early life adversity (ie, threat and deprivation) and reproductive strategies across global metrics. STUDY DESIGN We used data from 9674 middle-aged women of the China Health and Retirement Longitudinal Study. The experiences of threat and deprivation were assessed using the Life History Survey Questionnaire in 2014. Reproductive strategy information was assessed via self-report from the follow-up of 2013, 2015 and 2018, including age at menarche, age at natural menopause, age at first birth, total number of children, and number of abortions. Multivariate linear regression analyses were performed to assess the associations between distinct dimensions of early life adversity and multiple reproductive strategy indicators, adjusting for age, Hukou location, family socioeconomic status in adulthood and body mass index. RESULTS Of the 9674 women (mean [standard deviation] age at baseline, 55.89 [10.23] years), 4084 (42.20%) reported exposure to threat-related early life adversity and 7332 (75.79%) reported exposure to deprivation-related early life adversity. Early life adversity characterized by threat was associated with accelerated reproductive strategy. Compared with women who have no experiences of threat-related early life adversity, ≥3 threat-related early life adversity was associated with 3.7-month earlier age at menarche (β=-0.31, 95% confidence interval, -0.53 to -0.08; P=.007), 8.6-month earlier age at natural menopause (β=-0.72, 95% confidence interval, -1.29 to -0.15; P=.013), >1-year earlier age at first birth (β=-1.14, 95% confidence interval, -1.58 to -0.71; P<.0001), and an increased total number of children (β=0.25, 95% confidence interval, 0.10-0.41; P=.002). In contrast, experiences of deprivation were associated with delayed age at natural menopause (β=.50, 95% confidence interval, 0.06-0.94; P=.025) and increased number of abortions (β=.17, 95% confidence interval, 0.01-0.34, P=.037), in models adjusting for co-occurring threat exposures. CONCLUSION This study suggests that early life adversity characterized by threat was associated with accelerated reproductive strategy, whereas deprivation was associated with slower reproduction strategy. Future research should clarify the biological pathways between different dimensions of early life adversity and reproductive strategies and further determine whether accelerated reproduction is an adaptive response to early life adversity in humans.
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Lim J, Kim J, Lee J. Natural variation in reproductive timing and X-chromosome non-disjunction in Caenorhabditis elegans. G3 (Bethesda) 2021; 11:6373895. [PMID: 34550364 PMCID: PMC8664432 DOI: 10.1093/g3journal/jkab327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/02/2021] [Indexed: 11/12/2022]
Abstract
Caenorhabditis elegans hermaphrodites first produce a limited number of sperm cells, before their germline switches to oogenesis. Production of progeny then ensues until sperm is depleted. Male production in the self-progeny of hermaphrodites occurs following X-chromosome non-disjunction during gametogenesis, and in the reference strain increases with age of the hermaphrodite parent. To enhance our understanding of the reproductive timecourse in Caenorhabditis elegans, we measured and compared progeny production and male proportion during the early and late reproductive periods of hermaphrodites for 96 wild Caenorhabditis elegans strains. We found that the two traits exhibited natural phenotypic variation with few outliers and a similar reproductive timing pattern as previous reports. Progeny number and male proportion were not correlated in the wild isolates, implying that isolates with a large brood size did not produce males at a higher rate. We also identified loci and candidate genetic variants significantly associated with male-production rate in the late and total reproductive periods. Our results provide an insight into life history traits in wild Caenorhabditis elegans strains.
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Affiliation(s)
- Jiseon Lim
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826.,Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
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Lassek WD, Gaulin SJC. Does Nubility Indicate More Than High Reproductive Value? Nubile Primiparas' Pregnancy Outcomes in Evolutionary Perspective. Evol Psychol 2021; 19:14747049211039506. [PMID: 34524917 PMCID: PMC10355305 DOI: 10.1177/14747049211039506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022] Open
Abstract
The idea that human males are most strongly attracted to traits that peak in women in the nubile age group raises the question of how well women in that age group contend with the potential hazards of a first pregnancy. Using data for 1.7 million first births from 1990 U.S. natality and mortality records, we compared outcomes for women with first births (primiparas) aged 16-20 years (when first births typically occur in forager and subsistence groups) with those aged 21-25 years. The younger primiparas had a much lower risk of potentially life-threatening complications of labor and delivery and, when evolutionarily novel risk factors were controlled, fetuses which were significantly more likely to survive despite lower birth weights. Thus, nubile primiparas were more likely to have a successful reproductive outcome defined in an evolutionarily relevant way (an infant of normal birth weight and gestation, surviving to one year, and delivered without a medically necessary cesarean delivery). This suggests that prior to the widespread availability of surgical deliveries, men who mated with women in the nubile age group would have reaped the benefit of having a reproductive partner more likely to have a successful first pregnancy.
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Affiliation(s)
- William D. Lassek
- Department of Anthropology, HSSB 2001, University of California, Santa Barbara, CA, USA
| | - Steven J. C. Gaulin
- Department of Anthropology, HSSB 2001, University of California, Santa Barbara, CA, USA
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8
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Cheng L, Zhou X, Wang F, Hao M. The greater the economic inequality, the later people have children: The association between economic inequality and reproductive timing. Scand J Psychol 2020; 61:450-459. [PMID: 32012300 DOI: 10.1111/sjop.12612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 12/02/2019] [Indexed: 11/29/2022]
Abstract
Economic inequality is associated with a series of social outcomes, including health, social trust, and crime rates. However, little is known about the role of economic inequality as a characteristic of the socioecological environment in individuals' reproductive behavior. According to embodied capital theory, this research explored how individuals calibrate their reproductive timing to maximize payoffs to investment in embodied capital in an environment of high economic inequality. Five studies were conducted to test the hypothesis that higher economic inequality leads people to delay reproduction. Across nations (Study 1), we found that the average reproductive age is higher in nations with greater economic inequality. Study 2 found that people living in more economically unequal U.S. states tend to marry later. In Study 3, individuals who perceived higher levels of inequality in a given society planned to have their children later. Finally, in Study 4, the priming of high inequality led to a greater preference for delaying reproduction, which represented a desire to pursue one's development rather than to build a family (Study 4a and 4b). These results expand the literature regarding the effect of economic inequality on human behavior.
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Affiliation(s)
- Lei Cheng
- Beijing Key Laboratory of Applied Experimental Psychology, National Demonstration Center for Experimental Psychology Education, Faculty of Psychology, Beijing Normal University, Beijing, China
| | - Xuan Zhou
- Beijing Key Laboratory of Applied Experimental Psychology, National Demonstration Center for Experimental Psychology Education, Faculty of Psychology, Beijing Normal University, Beijing, China
| | - Fang Wang
- Beijing Key Laboratory of Applied Experimental Psychology, National Demonstration Center for Experimental Psychology Education, Faculty of Psychology, Beijing Normal University, Beijing, China
| | - Mingyang Hao
- Beijing Key Laboratory of Applied Experimental Psychology, National Demonstration Center for Experimental Psychology Education, Faculty of Psychology, Beijing Normal University, Beijing, China
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Berg V, Lawson DW, Rotkirch A. Financial opportunity costs and deaths among close kin are independently associated with reproductive timing in a contemporary high-income society. Proc Biol Sci 2020; 287:20192478. [PMID: 31964300 DOI: 10.1098/rspb.2019.2478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Evolutionary demography predicts that variation in reproductive timing stems from socio-ecologically contingent trade-offs between current and future reproduction. In contemporary high-income societies, the costs and benefits of current reproduction are likely to vary by socioeconomic status (SES). Two influential hypotheses, focusing on the parenthood 'wage penalty', and responses to local mortality have separately been proposed to influence the timing of parenthood. Economic costs of reproduction (i.e. income loss) are hypothesized to delay fertility, especially among high childhood SES individuals who experience greater opportunities to build capital through advantageous education and career opportunities. On the other hand, relatively low childhood SES individuals experience higher mortality risk, which may favour earlier reproduction. Here, we examine both hypotheses with a representative register-based, multigenerational dataset from contemporary Finland (N = 47 678). Consistent with each hypothesis, the predicted financial cost of early parenthood was smaller, and mortality among close kin was higher for individuals with lower childhood SES. Within the same dataset, lower predicted adulthood income and more kin deaths were also independently associated with earlier parenthood. Our results provide a robust demonstration of how economic costs and mortality relate to reproductive timing. We discuss the implications of our findings for demographic theory and public policy.
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Affiliation(s)
- V Berg
- Population Research Institute, Väestöliitto, Helsinki 00101, Finland.,Institute for Molecular Medicine Finland FIMM, University of Helsinki, Helsinki 00014, Finland
| | - D W Lawson
- Department of Anthropology, University of California, Santa Barbara, CA 93106-3210, USA
| | - A Rotkirch
- Population Research Institute, Väestöliitto, Helsinki 00101, Finland
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Pflüger LS, Pink KE, Böck A, Huffman MA, Wallner B. On the sunny side of (new) life: Effect of sunshine duration on age at first reproduction in Japanese macaques (Macaca fuscata). Am J Primatol 2019; 81:e23019. [PMID: 31243793 PMCID: PMC6773204 DOI: 10.1002/ajp.23019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 03/22/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022]
Abstract
To produce offspring early in life is energetically demanding and depends greatly on environmental conditions. In female primates, age at first reproduction (AFR) has been associated with social parameters (e.g., population density and social rank), food availability and meteorological conditions (e.g., photoperiod, rainfall patterns, and temperature). Regarding the latter, less attention has been given to the influence of sunshine. In nonhuman primates, including the northern‐most distributed Japanese macaque (Macaca fuscata), sunbathing is an effective thermoregulatory strategy to maintain sufficient energy intake during harsh winter months. Furthermore, the energetic value of sunshine and its role in the synthesis of essential vitamins important for sexual development and overall fertility is well investigated using human and animal models. In the present study, we hypothesized that female's AFR is influenced by the amount of sunshine in a semi‐free‐ranging, provisioned a group of Japanese macaques. To test this, we gathered data on sunshine duration in the year females theoretically experienced the onset of puberty. This phase of the female life cycle is particularly prone to the effects of environmental conditions. In addition to the investigation of sunshine duration and other meteorological conditions (i.e., rainfall and temperature) we controlled for social parameters (i.e., group size and sex ratio) as potential covariates. We found a clear effect of sunshine duration on female AFR: Females who entered puberty in years with more sunshine reproduced for the first time at significantly younger ages than females who experienced less sunshine during this specific period of their development. Possible mechanisms for how the sunshine influences sexual maturation in Japanese macaques are discussed. We investigated the influence of sunshine during the year of puberty onset on a female's age at first reproduction (AFR).
We used 20 years of birth data from a semi‐free‐ranging group of Japanese macaques and meteorological data provided online by local weather stations
We controlled for the influence of other meteorological conditions as well as for group size and socionomic sex ratio
Higher mean sunshine duration in the year of puberty onset significantly decreased females’ AFR.
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Affiliation(s)
- Lena S Pflüger
- Department of Behavioural Biology, University of Vienna, Vienna, Austria.,Austrian Research Center for Primatology, Ossiach, Austria.,Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Katharina E Pink
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria.,Family and Population Studies, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Anja Böck
- Department of Behavioural Biology, University of Vienna, Vienna, Austria.,Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Michael A Huffman
- Austrian Research Center for Primatology, Ossiach, Austria.,Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Vienna, Austria.,Austrian Research Center for Primatology, Ossiach, Austria
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Abstract
Objective: Few qualitative studies have explored women's use of social egg freezing. Derived from an interview study of 31 participants, this article explores the motivations of women using this technology. Methods: Semi-structured interviews were conducted with 31 users of social egg freezing resident in UK (n = 23), USA (n = 7) and Norway (n = 1). Interviews were face to face (n = 16), through Skype and Facetime (n = 9) or by telephone (n = 6). Data were analyzed using interpretive thematic analysis. Results: Women's use of egg freezing was shaped by fears of running out of time to form a conventional family, difficulties in finding a partner and concerns about "panic partnering", together with a desire to avoid future regrets and blame. For some women, use of egg freezing was influenced by recent fertility or health diagnoses as well as critical life events. A fifth of the participants also disclosed an underlying fertility or health issue as affecting their decision. Conclusion: The study provides new insights in to the complex motivations women have for banking eggs. It identifies how women's use of egg freezing was an attempt to "preserve fertility" in the absence of the particular set of "life conditions" they regarded as crucial for pursuing parenthood. It also demonstrates that few women were motivated by a desire to enhance their career and that the boundaries between egg freezing for medical and for social reasons may be more porous than first anticipated.
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Affiliation(s)
- Kylie Baldwin
- a School of Allied Health Sciences , De Montfort University , Leicester , UK
| | - Lorraine Culley
- a School of Allied Health Sciences , De Montfort University , Leicester , UK
| | - Nicky Hudson
- a School of Allied Health Sciences , De Montfort University , Leicester , UK
| | - Helene Mitchell
- a School of Allied Health Sciences , De Montfort University , Leicester , UK
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12
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Li Q, Luo S, Yang C, Li S, Guo J, He J, Chen Y, Huang C, Wu Z, Du W. Impacts of maternal characteristics and temperature on juvenile survival in the crocodile lizard: Implications for conservation. Zoo Biol 2019; 38:272-280. [PMID: 30614073 DOI: 10.1002/zoo.21473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 12/05/2018] [Accepted: 12/17/2018] [Indexed: 01/02/2023]
Abstract
Captive breeding is an important conservation measure that may restore and enhance wild populations of rare and endangered species. Multiple anthropogenic hazards have brought the crocodile lizard, Shinisaurus crocodilurus, to the brink of extinction. We initiated a captive breeding program and quantified female reproductive traits, including reproductive timing, litter size, litter mass, and neonate size. To identify the internal and external factors affecting female reproductive function, we then analyzed how maternal age is related to body size, temperature, and female reproductive traits. We found that larger female crocodile lizards produced more offspring than smaller ones, as both litter size and litter mass were positively related to maternal body size. In contrast, neonate size was independent of maternal body size. Maternal reproductive output varied among different age groups. Young and old females had significantly smaller living litter size and mass than middle-aged females. Among captive females, one-third exhibited early parturition in autumn and winter instead of the following spring, a pattern probably associated with higher ambient temperatures in captivity. Although female reproductive output and neonatal body size did not differ between early- and normal-parturition females, offspring from the former group died earlier than those from the latter. Our study highlights the danger of climate change in hastening parturition, a phenomenon that could significantly hamper neonate survival and impede population recruitment.
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Affiliation(s)
- Qiyu Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Shuyi Luo
- Daguishan National Nature Reserve for Crocodile Lizards, Hezhou, Guangxi, People's Republic of China
| | - Chunsheng Yang
- Daguishan National Nature Reserve for Crocodile Lizards, Hezhou, Guangxi, People's Republic of China
| | - Shuran Li
- College of Life and Environmental Science, Wenzhou University, Wenzhou, Zhejiang, People's Republic of China
| | - Jun Guo
- Daguishan National Nature Reserve for Crocodile Lizards, Hezhou, Guangxi, People's Republic of China
| | - Jiasong He
- Daguishan National Nature Reserve for Crocodile Lizards, Hezhou, Guangxi, People's Republic of China
| | - Yaohuan Chen
- Daguishan National Nature Reserve for Crocodile Lizards, Hezhou, Guangxi, People's Republic of China
| | - Chengming Huang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Zhengjun Wu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, People's Republic of China.,Guangxi Key Laboratory of Rare and Endangered Animal Ecology, Guangxi Normal University, Guilin, Guangxi, People's Republic of China
| | - Weiguo Du
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China
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13
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Abstract
As the average age of motherhood in many Western countries continues to rise, the spectacle of the older mother and the trend towards delayed childbearing has been the subject of much public debate and interest. Concurrent to this trend has been the development and use of a new form of fertility preservation - social egg freezing - a technology which by its very nature is meant to enable reproductive delay. Whilst previous studies have been able to provide insights into the complex and often interrelating structural, economic, and relational factors shaping the timing of motherhood, and in some cases women's use of social egg freezing, fewer studies have clearly demonstrated the way these factors themselves, as well as the accounts of individual women, can be seen as being shaped by ideological and discursive forces. Drawing on interviews with 31 users of social egg freezing this article will demonstrate how women's accounts of reproductive delay and use of egg freezing technology can be seen as being shaped by neoliberal rationality, heteronormativity, discourses of 'appropriate parenting' and gendered ideologies of parenthood.
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Affiliation(s)
- Kylie Baldwin
- Centre for Reproduction Research, De Montfort University, UK
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14
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Chelini MC, Hebets E. Field evidence challenges the often-presumed relationship between early male maturation and female-biased sexual size dimorphism. Ecol Evol 2017; 7:9592-9601. [PMID: 29187992 PMCID: PMC5696407 DOI: 10.1002/ece3.3450] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/14/2017] [Accepted: 08/15/2017] [Indexed: 11/25/2022] Open
Abstract
Female‐biased sexual size dimorphism (SSD) is often considered an epiphenomenon of selection for the increased mating opportunities provided by early male maturation (i.e., protandry). Empirical evidence of the adaptive significance of protandry remains nonetheless fairly scarce. We use field data collected throughout the reproductive season of an SSD crab spider, Mecaphesa celer, to test two hypotheses: Protandry provides fitness benefits to males, leading to female‐biased SSD, or protandry is an indirect consequence of selection for small male size/large female size. Using field‐collected data, we modeled the probability of mating success for females and males according to their timing of maturation. We found that males matured earlier than females and the proportion of virgin females decreased abruptly early in the season, but unexpectedly increased afterward. Timing of female maturation was not related to clutch size, but large females tended to have more offspring than small females. Timing of female and male maturation was inversely related to size at adulthood, as early‐maturing individuals were larger than late‐maturing ones, suggesting that both sexes exhibit some plasticity in their developmental trajectories. Such plasticity indicates that protandry could co‐occur with any degree and direction of SSD. Our calculation of the probability of mating success along the season shows multiple male maturation time points with similar predicted mating success. This suggests that males follow multiple strategies with equal success, trading‐off access to virgin females with intensity of male–male competition. Our results challenge classic hypotheses linking protandry and female‐biased SSD, and emphasize the importance of directly testing the often‐assumed relationships between co‐occurring animal traits.
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Affiliation(s)
| | - Eileen Hebets
- School of Biological Sciences University of Nebraska - Lincoln Lincoln NE USA
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15
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Afán I, Chiaradia A, Forero MG, Dann P, Ramírez F. A novel spatio-temporal scale based on ocean currents unravels environmental drivers of reproductive timing in a marine predator. Proc Biol Sci 2016; 282:rspb.2015.0721. [PMID: 26063848 DOI: 10.1098/rspb.2015.0721] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Life-history strategies have evolved in response to predictable patterns of environmental features. In practice, linking life-history strategies and changes in environmental conditions requires comparable space-time scales between both processes, a difficult match in most marine system studies. We propose a novel spatio-temporal and dynamic scale to explore marine productivity patterns probably driving reproductive timing in the inshore little penguin (Eudyptula minor), based on monthly data on ocean circulation in the Southern Ocean, Australia. In contrast to what occurred when considering any other fixed scales, little penguin's highly variable laying date always occurred within the annual peak of ocean productivity that emerged from our newly defined dynamic scale. Additionally, local sea surface temperature seems to have triggered the onset of reproduction, acting as an environmental cue informing on marine productivity patterns at our dynamic scale. Chlorophyll-a patterns extracted from this scale revealed that environment factors in marine ecosystems affecting breeding decisions are related to a much wider region than foraging areas that are commonly used in current studies investigating the link between animals' life history and their environment. We suggest that marine productivity patterns may be more predictable than previously thought when environmental and biological data are examined at appropriate scales.
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Affiliation(s)
- Isabel Afán
- Laboratorio de SIG y Teledetección (LAST-EBD), Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| | - André Chiaradia
- Research Department, Phillip Island Nature Parks, Victoria, Australia
| | - Manuela G Forero
- Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| | - Peter Dann
- Research Department, Phillip Island Nature Parks, Victoria, Australia
| | - Francisco Ramírez
- Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
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16
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Ramírez F, Afán I, Tavecchia G, Catalán IA, Oro D, Sanz-Aguilar A. Oceanographic drivers and mistiming processes shape breeding success in a seabird. Proc Biol Sci 2016; 283:20152287. [PMID: 26962134 PMCID: PMC4810842 DOI: 10.1098/rspb.2015.2287] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/11/2016] [Indexed: 11/12/2022] Open
Abstract
Understanding the processes driving seabirds' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.
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Affiliation(s)
- Francisco Ramírez
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Sevilla, Spain
| | - Isabel Afán
- Laboratorio de SIG y Teledetección (LAST-EBD), Estación Biológica de Doñana (CSIC), Sevilla, Spain
| | - Giacomo Tavecchia
- Population Ecology Group, IMEDEA, Miquel Marqués 21, Esporles, Spain
| | - Ignacio A Catalán
- Marine Ecosystem Dynamics Group, IMEDEA, Miquel Marqués 21, Esporles, Spain
| | - Daniel Oro
- Population Ecology Group, IMEDEA, Miquel Marqués 21, Esporles, Spain
| | - Ana Sanz-Aguilar
- Population Ecology Group, IMEDEA, Miquel Marqués 21, Esporles, Spain
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17
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Burghardt LT, Metcalf CJE, Donohue K. A cline in seed dormancy helps conserve the environment experienced during reproduction across the range of Arabidopsis thaliana. Am J Bot 2016; 103:47-59. [PMID: 26744481 DOI: 10.3732/ajb.1500286] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/03/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Understanding the factors shaping range limits is critical given current changes in climate as well as human-mediated introduction of species into novel environments. Phenological responses to climate influence range limits by allowing plants to avoid conditions that decrease population growth rates. Studying these processes is a challenge due to the joint contributions of both genetic and environmental variation to phenology. METHODS Using a previously developed model that predicts phenology of three dormancy "genotypes" in four locations spanning the European range of Arabidopsis thaliana, we examined how variation in seed dormancy influences the environmental conditions experienced by reproductive individuals and how those conditions influence reproductive potential. We calculated two metrics: temperature experienced during reproduction and the length of thermal window available for reproduction. KEY RESULTS Seed dormancy levels determine whether a spring-flowering life cycle is expressed and thus determine the reproductive environment. A genetic cline in seed dormancy across the range reduces differences in reproductive environment and increases the thermal opportunity for reproduction before conditions become unfavorable for survival. Counter-intuitively, these putatively local genotypes are predicted to reproduce in slightly cooler conditions in the south than in the north, suggesting that maternal environmental effects on average could induce deeper dormancy in southern seeds reinforcing the observed genetic cline. However, within a location, we found large individual level differences. CONCLUSIONS Phenological adjustments of early life stages can contribute to the maintenance of consistent reproductive environments experienced by individual plants across ranges despite variable environmental conditions over time and space.
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Affiliation(s)
- Liana T Burghardt
- Department of Biology, Duke University, Box 90338 Durham, North Carolina 27708 USA
| | - C Jessica E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544 USA
| | - Kathleen Donohue
- Department of Biology, Duke University, Box 90338 Durham, North Carolina 27708 USA
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18
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Morbey YE, Jensen EL, Russello MA. Time scale matters: genetic analysis does not support adaptation-by-time as the mechanism for adaptive seasonal declines in kokanee reproductive life span. Ecol Evol 2014; 4:3714-22. [PMID: 25478160 PMCID: PMC4224543 DOI: 10.1002/ece3.1214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 11/23/2022] Open
Abstract
Seasonal declines of fitness-related traits are often attributed to environmental effects or individual-level decisions about reproductive timing and effort, but genetic variation may also play a role. In populations of Pacific salmon (Oncorhynchus spp.), seasonal declines in reproductive life span have been attributed to adaptation-by-time, in which divergent selection for different traits occurs among reproductively isolated temporal components of a population. We evaluated this hypothesis in kokanee (freshwater obligate Oncorhynchus nerka) by testing for temporal genetic structure in neutral and circadian-linked loci. We detected no genetic differences in presumably neutral loci among kokanee with different arrival and maturation dates within a spawning season. Similarly, we detected no temporal genetic structure in OtsClock1b, Omy1009uw, or OmyFbxw11, candidate loci associated with circadian function. The genetic evidence from this study and others indicates a lack of support for adaptation-by-time as an important evolutionary mechanism underlying seasonal declines in reproductive life span and a need for greater consideration of other mechanisms such as time-dependent, adaptive adjustment of reproductive effort.
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Affiliation(s)
- Yolanda E Morbey
- Department of Biology, Western University London, Ontario, N6A 5B7, Canada
| | - Evelyn L Jensen
- Department of Biology, University of British Columbia, Okanagan Campus Kelowna, British Columbia, V1V 1V7, Canada
| | - Michael A Russello
- Department of Biology, University of British Columbia, Okanagan Campus Kelowna, British Columbia, V1V 1V7, Canada
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19
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Dubuc C, Ruiz-Lambides A, Widdig A. Variance in male lifetime reproductive success and estimation of the degree of polygyny in a primate. Behav Ecol 2014; 25:878-889. [PMID: 25024637 PMCID: PMC4095946 DOI: 10.1093/beheco/aru052] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 02/18/2014] [Accepted: 02/20/2014] [Indexed: 11/12/2022] Open
Abstract
The degree of polygyny is predicted to influence the strength of direct male-male competition, leading to a high variance in male lifetime reproductive success and to reproduction limited to the prime period of adulthood. Here, we explore the variance in male lifetime reproductive success and reproductive time in an anthropoid primate forming multimale-multifemale groups. Males of this species form dominance hierarchies, which are expected to skew reproduction toward few high-ranking males. At the same time, however, females mate with multiple males (polygynandry), which should limit the degree of polygyny. Using 20 years of genetic and demographic data, we calculated lifetime reproductive success for the free-ranging rhesus macaque (Macaca mulatta) population of Cayo Santiago for subjects that died naturally or reached senescence. Our results show that 1) male lifetime reproductive success was significantly skewed (range: 0-47 offspring; males reproducing below average: 62.8%; nonbreeders: 17.4%), 2) variance in male lifetime reproductive success was 5 times larger than in females, and 3) male lifetime reproductive success was more influenced by variation in fecundity (60%) than longevity (25%), suggesting that some direct male-male competition takes place. However, the opportunity for selection (i.e., standardized variance in male lifetime reproductive success) is low compared with that in other large mammal species characterized by a high degree of polygyny. Moreover, male reproductive life extended much beyond the prime period, showing that physical strength was not required to acquire mates. We conclude that rhesus macaques exhibit a moderate degree of polygyny and, therefore, low levels of direct male-male competition for fertile females, despite the fact that males form linear dominance hierarchies.
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Affiliation(s)
- Constance Dubuc
- Junior Research Group of Primate Kin Selection, Department of Primatology, Max-Planck Institute for Evolutionary Anthropology , Deutscher Platz 6, 04103 Leipzig , Germany , ; Center for the Study of Human Origins, Department of Anthropology, New York University , 25 Waverly Place, New York, NY 10003 , USA
| | - Angelina Ruiz-Lambides
- Junior Research Group of Primate Kin Selection, Department of Primatology, Max-Planck Institute for Evolutionary Anthropology , Deutscher Platz 6, 04103 Leipzig , Germany , ; Cayo Santiago, Caribbean Primate Research Center, University of Puerto Rico , PO Box 306, Punta Santiago, PR 00741 , USA , and
| | - Anja Widdig
- Junior Research Group of Primate Kin Selection, Department of Primatology, Max-Planck Institute for Evolutionary Anthropology , Deutscher Platz 6, 04103 Leipzig , Germany , ; Research Group of Behavioural Ecology, Institute of Biology, Faculty of Bioscience, Pharmacy and Psychology, University of Leipzig , Talstrasse 33, 04103 Leipzig , Germany
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20
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Klaus SP, Lougheed SC. Changes in breeding phenology of eastern Ontario frogs over four decades. Ecol Evol 2013; 3:835-45. [PMID: 23610628 PMCID: PMC3631398 DOI: 10.1002/ece3.501] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 01/04/2013] [Accepted: 01/17/2013] [Indexed: 11/11/2022] Open
Abstract
Global climate change has been implicated in phenological shifts for a variety of taxa. Amphibian species in particular are sensitive to changes in their environment due to their biphasic life history and restricted reproductive requirements. Previous research has shown that not all temperate amphibian species respond similarly to the same suite of climatic or environmental cues, nor are individual species necessarily uniform in their responses across their range. We examined both the timing of spring emergence and calling phenology of eight anuran species in southeastern Ontario, Canada, using an approximately 40-year dataset of historical records of amphibian activity. Rana pipiens was the only species out of eight considered to emerge significantly earlier, by an estimated 22 days over four decades. Both R. pipiens and Bufo americanus have advanced initiation of calling over a four-decade span significantly earlier by an estimated 37.2 and 19.2 days, respectively. Rana sylvatica showed a trend toward earlier emergence by 19 days, whereas we did not detect changes in emergence phenology for the remaining five species. This significant shift in breeding behavior for two species correlates to significant regional increases in spring temperatures of an estimated 2.7-2.8°C overall over four decades. Our study suggests that local temperature increases have affected the timing of emergence and the onset of calling activity in some Ontario anuran species. Global decline or range shifts ultimately may be related to changes in reproductive behavior and timing mediated by shifting climate.
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Abstract
BACKGROUND AND AIMS Trithuria, the sole genus in the family Hydatellaceae, is an important group for understanding early angiosperm evolution because of its sister relationship to the ancient lineage, Nymphaeales (water lilies). Although also aquatic, Trithuria differs from water lilies in that all species are extremely small, and most have an annual life form and grow in seasonal wetlands. Very little is known about their reproductive ecology. This paper reports on reproductive timing, mode of pollination and characteristics of the breeding system of Trithuria submersa in Western Australia. METHODS Mass collections of open-pollinated plants from different ecological settings were used to characterize the reproductive developmental sequence and natural pollen reception. Hand-pollination, caging and emasculation experiments were used to measure outcross + geitonogamous pollen reception versus autonomous self-pollination in two populations over two field seasons. KEY RESULTS Natural outcross or geitonogamous pollination was by wind, not by water or insects, but pollen reception was extremely low. Pollen production was very low and pollen release was non-synchronous within populations. The pollen to ovule (P/O) ratio was 23·9, compared with 1569·1 in dioecious Trithuria austinensis. Stigmas became receptive before male phase and remained so until anthers dehisced and autonomous self-pollination occurred. Natural pollen loads are composed primarily of self pollen. Self- and open-pollinated plants had equivalent seed set (both >70 %). Self-pollinated plants produced seed within 17 d. CONCLUSIONS Autonomous self-pollination and self-fertilization are predominant in T. submersa. The low P/O ratio is not an artefact of small plant size and is inconsistent with long-term pollination by wind. It indicates that T. submersa has evolved a primarily autogamous breeding system. Selfing, along with the effect of small plant size on the speed of reproduction, has enabled T. submersa to colonize marginal ephemeral wetlands in the face of unpredictable pollination.
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Affiliation(s)
- Mackenzie L Taylor
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA.
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