1
|
Borries C, Koenig A. Female-biased birth sex ratio in a female dispersal primate suggests local resource competition. Biol Lett 2024; 20:20240002. [PMID: 38689558 PMCID: PMC11061642 DOI: 10.1098/rsbl.2024.0002] [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: 01/02/2024] [Revised: 02/12/2024] [Accepted: 02/27/2024] [Indexed: 05/02/2024] Open
Abstract
Group living may entail local resource competition (LRC) which can be reduced if the birth sex ratio (BSR) is biased towards members of the dispersing sex who leave the group and no longer compete locally with kin. In primates, the predicted relationship between dispersal and BSR is generally supported although data for female dispersal species are rare and primarily available from captivity. Here, we present BSR data for Phayre's leaf monkeys (Trachypithecus phayrei crepusculus) at the Phu Khieo Wildlife Sanctuary, Thailand (N = 104). In this population, nearly all natal females dispersed, while natal males stayed or formed new groups nearby. The slower reproductive rate in larger groups suggests that food can be a limiting resource. In accordance with LRC, significantly more females than males were born (BSR 0.404 males/all births) thus reducing future competition with kin. This bias was similar in 2-year-olds (no sex-differential mortality). It became stronger in adults, supporting our impression of particularly fierce competition among males. To better evaluate the importance of BSR, more studies should report sex ratios throughout the life span, and more data for female dispersal primates need to be collected, ideally for multiple groups of different sizes and for several years.
Collapse
Affiliation(s)
- Carola Borries
- Department of Anthropology and Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Andreas Koenig
- Department of Anthropology and Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, USA
- Graduate Program in Ecology and Evolution, Stony Brook University, Stony Brook, NY, USA
| |
Collapse
|
2
|
Barra T, Viblanc VA, Saraux C, Murie JO, Dobson FS. Parental investment in the Columbian ground squirrel: empirical tests of sex allocation models. Ecology 2021; 102:e03479. [PMID: 34270793 DOI: 10.1002/ecy.3479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/04/2021] [Accepted: 05/19/2021] [Indexed: 11/09/2022]
Abstract
Parental allocation of resources into male or female offspring and differences in the balance of offspring sexes in natural populations are central research topics in evolutionary ecology. Fisher (Fisher, R. A. 1930. The genetical theory of natural selection, Clarendon Press, Oxford, UK) identified frequency-dependent selection as the mechanism responsible for an equal investment in the sexes of offspring at the end of parental care. Three main theories have been proposed for explaining departures from Fisherian sex ratios in light of variation in environmental (social) and individual (maternal condition) characteristics. The Trivers-Willard model (Trivers, R., and D. Willard. 1973. Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90-92) of male-biased sex allocation by mothers in the best body condition is based on the competitive ability of male offspring for future access to mates and thus superior reproduction. The local resource competition model is based on competitive interactions in matrilines, as occur in many mammal species, where producing sons reduces future intrasexual competition with daughters. A final model invokes advantages of maintaining matrilines for philopatric females, despite any increased competition among females. We used 29 yr of pedigree and demographic data to evaluate these hypotheses in the Colombian ground squirrel (Urocitellus columbianus), a semisocial species characterized by strong female philopatry. Overall, male offspring were heavier than female offspring at birth and at weaning, suggesting a higher production cost. With more local kin present, mothers in the best condition biased their offspring sex ratio in favor of males, and mothers in poor condition biased offspring sex ratio in favor of females. Without co-breeding close kin, the pattern was reversed, with mothers in the best condition producing more daughters, and mothers in poor condition producing more sons. Our results do not provide strong support for any of the single-factor models of allocation to the sexes of offspring, but rather suggest combined influences of relative maternal condition and matriline dominance on offspring sex ratio.
Collapse
Affiliation(s)
- Thibaut Barra
- Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, Strasbourg, 67000, France
| | - Vincent A Viblanc
- Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, Strasbourg, 67000, France
| | - Claire Saraux
- Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, Strasbourg, 67000, France
| | - Jan O Murie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - F Stephen Dobson
- Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, Strasbourg, 67000, France.,Department of Biological Sciences, Auburn University, 311 Funchess Hall, Auburn, Alabama, 36849, USA
| |
Collapse
|
3
|
Dias PAD, Montero Domínguez IL, Rangel Negrín A. Factors influencing infant sex ratio in howler monkeys (Alouatta spp.): A literature review and analysis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 172:48-57. [PMID: 32141069 DOI: 10.1002/ajpa.24035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/11/2020] [Accepted: 02/19/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Frequency-dependent selection is expected to maintain infant sex ratios around parity over evolutionary time. However, over ecological time periods, infant sex ratios vary, and it has been proposed that this variation may reflect adaptive processes. In primates, there are consistent patterns of variation in infant sex ratios, although their adaptive significance remains contentious. In addition to design issues, contrasting results could have derived across primates from variation in the fitness benefits accrued through sons or daughters associated with the specific social, ecological, and demographic context of populations. Thus, different sex allocation tactics could occur within species over time and space. METHODS We reviewed the literature to describe variation in infant sex ratio in howler monkeys (genus Alouatta) and to examine whether such a variation could be associated with adaptive sex allocation. We found 26 studies that provided data for this review. These studies yielded 96 infant sex reports, corresponding to 1,477 sexed infants. RESULTS Infant sex ratio across howler monkey species tends to parity, but females produce more sons under high group densities and more daughters when rainfall increases. DISCUSSION Based on these results, as well as on information on howler monkey dispersal patterns, demography, and within-group genetic relatedness, we speculate that, depending on population growth stage, sex allocation is explained by (a) local resource enhancement, that is, more cooperative philopatric daughters are produced when populations are growing; and (b) local resource competition, that is, more dispersing sons are produced when populations are saturated. Thus, there is evidence suggestive of adaptive variation in infant sex ratios in howler monkeys.
Collapse
Affiliation(s)
- Pedro A D Dias
- Primate Behavioral Ecology Lab, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| | - Irma L Montero Domínguez
- Primate Behavioral Ecology Lab, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| | - Ariadna Rangel Negrín
- Primate Behavioral Ecology Lab, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| |
Collapse
|
4
|
The global male-bias in sex ratio at birth is sustained by the sex ratio genotypes of replacement offspring. Genetica 2019; 147:249-258. [DOI: 10.1007/s10709-019-00074-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 07/18/2019] [Indexed: 10/26/2022]
|
5
|
Perret M. Revisiting the Trivers-Willard theory on birth sex ratio bias: Role of paternal condition in a Malagasy primate. PLoS One 2018; 13:e0209640. [PMID: 30576370 PMCID: PMC6303032 DOI: 10.1371/journal.pone.0209640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/10/2018] [Indexed: 11/19/2022] Open
Abstract
Within current theories on potential adaptive manipulation of offspring sex ratio, giving birth to a male or to a female is assumed to depend on the capacity of the mother to invest in offspring to maximize her fitness. The active role of the father in sex ratio bias at birth has been neglected until recently. The human sex ratio at birth is biased towards sons, although in occidental populations, the ratio has decreased regularly for 30 years and could be the consequence of the adverse effects of environmental chemicals on male hormones. In a Malagasy primate, the lesser mouse lemur, the potential effect of paternal testosterone levels on sex ratio bias at birth was tested on 130 litters (278 babies) produced in 52 mixed-sex groups. For each group, social dominance among males was characterized based on aggressive interactions and sexual behaviours. Using a multi correspondence analysis, high testosterone levels in grouped males, particularly those of the dominant male, were significantly correlated with more infants produced in male-biased litters, independent of the female condition. According to these results, predictions for sex ratio bias towards one sex or the other in mouse lemurs were discussed considering the influence of both parents.
Collapse
Affiliation(s)
- Martine Perret
- UMR Mecadev 7179 CNRS-MNHN, Département Adaptations du Vivant, Brunoy, France
| |
Collapse
|
6
|
Rangel-Negrín A, Coyohua-Fuentes A, Canales-Espinosa D, Chavira-Ramírez DR, Dias PAD. Maternal glucocorticoid levels affect sex allocation in black howler monkeys. J Zool (1987) 2017. [DOI: 10.1111/jzo.12503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. Rangel-Negrín
- Primate Behavioral Ecology Lab; Instituto de Neuroetología; Universidad Veracruzana; Xalapa Veracruz México
| | - A. Coyohua-Fuentes
- Primate Behavioral Ecology Lab; Instituto de Neuroetología; Universidad Veracruzana; Xalapa Veracruz México
| | - D. Canales-Espinosa
- Primate Behavioral Ecology Lab; Instituto de Neuroetología; Universidad Veracruzana; Xalapa Veracruz México
| | - D. R. Chavira-Ramírez
- Belisario Domínguez Sección XVI; Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubirán”; Tlalpan México
| | - P. A. D. Dias
- Primate Behavioral Ecology Lab; Instituto de Neuroetología; Universidad Veracruzana; Xalapa Veracruz México
| |
Collapse
|
7
|
Lemasson A, Jubin R, Bec P, Hausberger M. Factors of influence and social correlates of parturition in captive Campbell's monkeys: Case study and breeding data. Am J Primatol 2017; 79. [DOI: 10.1002/ajp.22632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/24/2016] [Accepted: 11/29/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Alban Lemasson
- Université de Rennes 1; Ethologie animale et humaine, EthoS U.M.R. 6552 - C.N.R.S.; Paimpont France
| | - Ronan Jubin
- Université de Rennes 1; Ethologie animale et humaine, EthoS U.M.R. 6552 - C.N.R.S.; Paimpont France
| | - Philippe Bec
- Université de Rennes 1; Ethologie animale et humaine, EthoS U.M.R. 6552 - C.N.R.S.; Paimpont France
| | - Martine Hausberger
- C.N.R.S.; Ethologie animale et humaine, EthoS U.M.R. 6552 - Université de Rennes 1; Rennes France
| |
Collapse
|
8
|
Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei): influential factors. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2066-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
9
|
De Roissart A, Wybouw N, Renault D, Van Leeuwen T, Bonte D. Life‐history evolution in response to changes in metapopulation structure in an arthropod herbivore. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12612] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Annelies De Roissart
- Department Biology Terrestrial Ecology Unit Ghent University K.L. Ledeganckstraat 35 Ghent B‐9000 Belgium
| | - Nicky Wybouw
- Department of Crop Protection Laboratory of Agrozoology Ghent University Coupure Links 653 Ghent B‐9000 Belgium
- Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam Science Park 904 1098 XH Amsterdam the Netherlands
| | - David Renault
- UMR 6553 ECOBIO CNRS Université de Rennes 1 Avenue du Gal Leclerc 263 CS 74205 35042 Rennes Cedex France
| | - Thomas Van Leeuwen
- Department of Crop Protection Laboratory of Agrozoology Ghent University Coupure Links 653 Ghent B‐9000 Belgium
- Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam Science Park 904 1098 XH Amsterdam the Netherlands
| | - Dries Bonte
- Department Biology Terrestrial Ecology Unit Ghent University K.L. Ledeganckstraat 35 Ghent B‐9000 Belgium
| |
Collapse
|
10
|
Schwanz LE, Robert KA. Proximate and ultimate explanations of mammalian sex allocation in a marsupial model. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1720-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Skewed birth sex ratios in primates: Should high-ranking mothers have daughters or sons? Trends Ecol Evol 2012; 8:395-400. [PMID: 21236210 DOI: 10.1016/0169-5347(93)90040-v] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous studies have been published on the skewed birth sex ratios among non-human primate populations. Sometimes the observed tendencies in sex ratio variations have been contradictory, and their adaptive significance has been controversial. Recent studies seem to reveal that the local resource competition among philopatric sex is the most important selective force affecting primate birth sex ratios. However, our understanding on this issue is still greatly hampered by the lack of exact knowledge on male reproductive success and the proximate mechanisms to vary sex ratios.
Collapse
|
12
|
Monclús R, Tiulim J, Blumstein DT. Older mothers follow conservative strategies under predator pressure: the adaptive role of maternal glucocorticoids in yellow-bellied marmots. Horm Behav 2011; 60:660-5. [PMID: 21930131 DOI: 10.1016/j.yhbeh.2011.08.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/31/2011] [Accepted: 08/31/2011] [Indexed: 11/29/2022]
Abstract
When the maternal environment is a good predictor of the offspring environment, maternal glucocorticoid (GC) levels might serve to pre-program offspring to express certain phenotypes or life-history characteristics that will increase their fitness. We conducted a field study to assess the effects of naturally occurring maternal GC levels on their offspring in yellow-bellied marmots (Marmota flaviventris) subjected to different predator pressures. Maternal fecal corticosteroid metabolites (FCM) were positively correlated with predator pressure. Predators had both direct and indirect effects on pups. We found that older mothers with higher FCM levels had smaller and female-biased litters. Moreover, sons from older mothers with high FCM levels dispersed significantly more than those from older mothers with low FCM levels, whereas the opposite pattern was found in pups from younger mothers. These age-related effects may permit females to make adaptive decisions that increase their pups' fitness according to their current situation.
Collapse
Affiliation(s)
- Raquel Monclús
- Department of Ecology and Evolutionary Biology, University of California, 621 Charles E Young Drive South, Los Angeles, CA 90095-1606, USA.
| | | | | |
Collapse
|
13
|
Weladji RB, Laflamme-Mayer K. Influence of environmental conditions on sex allocation in the black rhinoceros population of Mkhuze Game Reserve, South Africa. Afr J Ecol 2011. [DOI: 10.1111/j.1365-2028.2011.01280.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
14
|
Guillon JM, Bottein J. A spatially explicit model of sex ratio evolution in response to sex-biased dispersal. Theor Popul Biol 2011; 80:141-9. [PMID: 21570994 DOI: 10.1016/j.tpb.2011.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 04/12/2011] [Accepted: 04/28/2011] [Indexed: 11/28/2022]
Abstract
Sex-biased dispersal occurs in all seed plants and many animal species. Theoretical models have shown that sex-biased dispersal can lead to evolutionarily stable biased sex ratios. Here, we use a spatially explicit chessboard model to simulate the evolution of sex ratio in response to sex-biased dispersal range and sex-biased dispersal rate. Two life cycles are represented in the model: one in which both sexes disperse before mating (DDM), the other in which males disperse before mating and mated females or zygotes disperse after mating (DMD). Model parameters include factors like dispersal rate, dispersal range, number of individuals per patch, and habitat heterogeneity. When dispersal range is sex biased, we find that, in a homogeneous environment, the sex ratio is generally biased towards the sex that disperses more widely (sex ratio range: 0.47-0.52). In a heterogeneous environment, the sex ratio is generally biased towards the more dispersive sex in good habitats, and towards the less dispersive sex in poor habitats (sex ratio range: 0-1). This is opposite to the effect of sex-biased dispersal rate, which favours the production of the more dispersive sex in poor habitats and the less dispersive sex in good habitats (sex ratio range: 0-1). To allow for a comparison with theoretical predictions, data concerning sex-biased dispersal and habitat-dependent sex ratios should thus incorporate information about the spatial scale of both dispersal and environmental heterogeneity.
Collapse
Affiliation(s)
- Jean-Michel Guillon
- Laboratoire Ecologie, Systématique et Evolution, AgroParisTech, CNRS, Université Paris-Sud, Orsay, France.
| | | |
Collapse
|
15
|
ROBERT KA, SCHWANZ LE. Emerging sex allocation research in mammals: marsupials and the pouch advantage. Mamm Rev 2010. [DOI: 10.1111/j.1365-2907.2010.00168.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
16
|
Lee DE, Sydeman WJ. North Pacific Climate Mediates Offspring Sex Ratio in Northern Elephant Seals. J Mammal 2009. [DOI: 10.1644/08-mamm-a-130.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
17
|
Grant VJ, Irwin RJ. A simple model for adaptive variation in the sex ratios of mammalian offspring. J Theor Biol 2009; 258:38-42. [PMID: 19490877 DOI: 10.1016/j.jtbi.2009.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 01/09/2009] [Accepted: 01/09/2009] [Indexed: 11/26/2022]
Abstract
We present a simple mathematical model that describes how primary and secondary sex ratios of offspring may vary adaptively in order to maintain equal numbers of the sexes at the age of reproductive maturity. The model postulates that the sex of an offspring depends probabilistically on a weighted linear combination of maternal testosterone and male vulnerability. The model operates at population level, and is based on three physiological phenomena: first that maternal testosterone in follicular fluid is normally distributed, with levels above the mean more likely to be associated with the conception of males; secondly, that males are more vulnerable than females from conception onwards; and thirdly that under conditions of chronic stress, increased secretion of female testosterone coincides with increased male vulnerability. Thus during times of chronic stress, more males are conceived, but their number of live births is moderated by increased male loss. Variations in secondary sex ratios should therefore be related not only to the stressfulness of environmental conditions, but also to the timing of changes in stressfulness.
Collapse
Affiliation(s)
- Valerie J Grant
- Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1. New Zealand.
| | | |
Collapse
|
18
|
Silk JB, Brown GR. Local resource competition and local resource enhancement shape primate birth sex ratios. Proc Biol Sci 2008; 275:1761-5. [PMID: 18445562 PMCID: PMC2587797 DOI: 10.1098/rspb.2008.0340] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 04/10/2008] [Accepted: 04/11/2008] [Indexed: 11/12/2022] Open
Abstract
Sex ratio theory provides a powerful source of testable predictions about sex allocation strategies. Although studies of invertebrates generally support predictions derived from the sex ratio theory, evidence for adaptive sex ratio biasing in vertebrates remains contentious. This may be due to the fact that most studies of vertebrates have focused on facultative adjustment in relation to maternal condition, rather than processes that might produce uniform sex biases across individuals. Here, we examine the effects of local resource enhancement (LRE) and local resource competition (LRC) on birth sex ratios (BSRs). We also examine the effects of sex differences in the costs of rearing male and female offspring on BSRs. We present data from 102 primate species and show that BSRs are skewed in favour of the dispersing sex in species that do not breed cooperatively, as predicted by the LRC model. In accordance with the LRE model, BSRs are generally skewed in favour of the more beneficial sex in cooperatively breeding primate species. There is no evidence that BSRs reflect the extent of sexual size dimorphism, an indirect measure of the costs of rearing male and female offspring. These analyses suggest that adaptive processes may play an important role in the evolution of BSRs in vertebrates.
Collapse
Affiliation(s)
- Joan B Silk
- Department of Anthropology, University of California Los Angeles, Los Angeles, CA 90095-1553, USA.
| | | |
Collapse
|
19
|
Qi XG, Li BG, Ji WH. Reproductive parameters of wild female Rhinopithecus roxellana. Am J Primatol 2008; 70:311-9. [PMID: 17968907 DOI: 10.1002/ajp.20480] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
On the basis on 6 years of observation, we estimated the reproductive parameters of a Golden snub-nosed monkey (Rhinopithecus roxellana) group in the Qinling Mountains, China. We observed 88 births in 47 females from 2001 to 2006. Two methods were used to calculate the birthrate. The first method is based on the number of births observed in a year, giving 0.49+/-0.07 (mean+/-SD), and the second method is based on the female-years of observation, giving 0.49+/-0.17 births per female per year in this troop. The mean interbirth interval is 21.88+/-6.01 months (mean+/-SD). The mortality of infant born between 2002 and 2005 was 22.4%. The interbirth intervals of females that had lost an infant before the age of 6 months were significantly shorter than that of females whose infants survived for more than 6 months. A female usually gives birth once every 2 years if the previous offspring survives to a weaning age of 5-6 months, or will give birth in the next year if the previous young dies before reaching an age of 6 months. Births were significantly concentrated during March to May of each year. The mean birth date was on April 14, median was April 12; and the standard deviation was 13.98 days. Birth peak occurs 6-7 months after mating peak. From observations on 15 individuals that gave birth for the first time, we concluded that the wild female Golden snub-nosed monkeys in Qinling Mountains start giving birth at an age of 5 or 6 years. We suggest that the seasonal reproductive pattern is an adaptive response to the availability of seasonal food. Our results are consistent with the hypothesis that these reproductive characteristics are a result of adaptation to the seasonality of mountain climate and food resources.
Collapse
Affiliation(s)
- Xiao-Guang Qi
- College of Life Sciences, and Key Laboratory of Resource Biology and Biotechnology in Western China of Ministry of Education, Northwest University, Xi'an, People's Republic of China
| | | | | |
Collapse
|
20
|
Wild G, West S. A Sex Allocation Theory for Vertebrates: Combining Local Resource Competition and Condition‐Dependent Allocation. Am Nat 2007; 170:E112-28. [DOI: 10.1086/522057] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 07/13/2007] [Indexed: 11/03/2022]
|
21
|
Grant VJ. Could maternal testosterone levels govern mammalian sex ratio deviations? J Theor Biol 2007; 246:708-19. [PMID: 17379251 DOI: 10.1016/j.jtbi.2007.02.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 02/06/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Although maternal dominance and good condition are frequently associated with raised offspring sex ratios in mammals, the key factor may be female testosterone, which not only underpins the behavioural indicators but could also provide a pathway to a possible proximate mechanism for sex determination. By taking into account the fact that female testosterone levels rise in response to environmental stressors, it is possible to re-interpret the findings of atypical sex ratios in mammals in a way that reconciles seemingly conflicting results and reveals instead what could be a coherent, adaptive system of sex allocation in mammals.
Collapse
Affiliation(s)
- Valerie J Grant
- Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1, New Zealand.
| |
Collapse
|
22
|
Kusahara M, Kamimura Y, Tamura N, Hayashi F. A new pair of primers for molecular sexing of the Pallas squirrel, Callosciurus erythraeus, and variation in fetal sex ratio. MAMMAL STUDY 2006. [DOI: 10.3106/1348-6160(2006)31[87:anpopf]2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
23
|
Martin JK, Handasyde KA. Comparison of bobuck (
Trichosurus cunninghami
) demography in two habitat types in the Strathbogie Ranges, Australia. J Zool (1987) 2006. [DOI: 10.1111/j.1469-7998.2006.00207.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. K. Martin
- Department of Zoology, The University of Melbourne, Vic., Australia
| | - K. A. Handasyde
- Department of Zoology, The University of Melbourne, Vic., Australia
| |
Collapse
|
24
|
Liang H, Zhang Z. Food restriction affects reproduction and survival of F1 and F2 offspring of Rat-like hamster (Cricetulus triton). Physiol Behav 2006; 87:607-13. [PMID: 16458335 DOI: 10.1016/j.physbeh.2005.12.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2005] [Revised: 12/16/2005] [Accepted: 12/16/2005] [Indexed: 11/22/2022]
Abstract
Food restriction in parent may have long-term consequence on the reproductive capabilities of the offspring, and these consequences may, in turn, play an important role in population regulation. In this paper, we systematically examined the effect of maternal food restriction on reproduction and survival of maternal individuals, and F1 and F2 offspring of Rat-like hamsters (Cricetulus triton). Food restriction to 75% of that eaten by ad libitum-fed hamsters (75% FR) did not affect the reproductive organs and hormone concentration of maternal females, but 50% FR significantly reduced the size of ovarian organ and estradiol concentration of maternal females. 75% FR significantly reduced the testosterone concentration of maternal males; 50% FR significantly reduced both the size of epididymides and concentration of testosterone of maternal males. 70% FR in maternal females significantly reduced the sizes of reproductive organs and hormone concentrations of both their male and female F1 offspring. FR maternal females also produced significantly more male than female F1 offspring. The sizes of reproductive organs or hormone concentration of F2 males of maternal FR continued to significantly decline, but no such effect was observed in F2 females. However, the number of F2 offspring per F1 female of FR maternal females at birth became significantly smaller and with significantly more males than females. Survival to weaning of F1 and F2 offspring of FR maternal females became significantly smaller during the period from birth to weaning. Thus, the effects of maternal food restriction could be an important mechanism to explain the prolonged low population density that is commonly observed after the population crash of this species.
Collapse
Affiliation(s)
- Hong Liang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuanxi Road, Haidian District, Beijing 100080, PR China
| | | |
Collapse
|
25
|
|
26
|
West SA, Shuker DM, Sheldon BC. SEX-RATIO ADJUSTMENT WHEN RELATIVES INTERACT: A TEST OF CONSTRAINTS ON ADAPTATION. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01772.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
27
|
ISAAC JOANNEL, KROCKENBERGER ANDREWK, JOHNSON CHRISTOPHERN. Adaptive sex allocation in relation to life-history in the common brushtail possum, Trichosurus vulpecula. J Anim Ecol 2005. [DOI: 10.1111/j.1365-2656.2005.00954.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
28
|
Perret M. Relationship between urinary estrogen levels before conception and sex ratio at birth in a primate, the gray mouse lemur. Hum Reprod 2005; 20:1504-10. [PMID: 15790612 DOI: 10.1093/humrep/deh802] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In primates, including humans, bias of sex ratio at birth has been reported to depend on maternal condition at conception. In a Malagasy primate, the gray mouse lemur, male-biased sex ratio at birth occurred in captive parous females. The male bias was previously demonstrated to be pre-conceptual and independent of the female's nutritional state. It was hypothesized to be related to changes in hormonal state at ovulation. METHODS AND RESULTS The relationship between urinary estradiol (E2) levels during the follicular phase until estrus and litter production (number and sex of newborns) was assessed in 91 females mated under controlled conditions. Changes in E2 levels prior to ovulation followed the typical primate pattern characterized by a gradual rise during the 10 days preceding the sharp increase at estrus. A clear decline in E2 levels occurred with ageing. Direction of the sex ratio bias was unrelated to E2 levels at ovulation time but was significantly dependent on E2 levels during the follicular phase. Reduced E2 levels prior to estrus led to male-biased litters. CONCLUSION This study suggests that hormonal stimulation during the follicular phase plays a role in shifting sex ratio at conception through changes in the local environment of the ova. This hypothesis deserves testing by assessing estrogen levels throughout the follicular phase in other primate species including humans.
Collapse
Affiliation(s)
- M Perret
- Département d'Ecologie et Gestion de la Biodiversité, CNRS-MNHN, UMR 5176, 4 avenue du petit château, 91800 Brunoy, France.
| |
Collapse
|
29
|
West SA, Shuker DM, Sheldon BC. SEX-RATIO ADJUSTMENT WHEN RELATIVES INTERACT: A TEST OF CONSTRAINTS ON ADAPTATION. Evolution 2005. [DOI: 10.1554/04-158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
30
|
Blanchard P, Festa-Bianchet M, Gaillard JM, Jorgenson JT. Maternal condition and offspring sex ratio in polygynous ungulates: a case study of bighorn sheep. Behav Ecol 2004. [DOI: 10.1093/beheco/arh153] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
31
|
Setchell JM, Kappeler PM. Selection in Relation to Sex in Primates. ADVANCES IN THE STUDY OF BEHAVIOR 2003. [DOI: 10.1016/s0065-3454(03)33003-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
32
|
Brown GR, Silk JB. Reconsidering the null hypothesis: Is maternal rank associated with birth sex ratios in primate groups? Proc Natl Acad Sci U S A 2002; 99:11252-5. [PMID: 12177424 PMCID: PMC123242 DOI: 10.1073/pnas.162360599] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2002] [Accepted: 06/17/2002] [Indexed: 11/18/2022] Open
Abstract
Trivers and Willard hypothesized that vertebrates adaptively vary the sex ratio of their offspring in response to the mother's physical condition [Trivers, R. L. & Willard, D. (1973) Science 179, 90-92]. This hypothesis has produced considerable debate within evolutionary biology. Here we use meta-analysis techniques to evaluate claims that nonhuman primate females facultatively adjust the sex ratio of their progeny in relation to their own dominance rank in a uniform way. The magnitude of the difference in birth sex ratios of high- and low-ranking females declines as sample sizes increase, and the mean difference in birth sex ratios of high- and low-ranking females is zero. These results suggest that the observed effects could be the product of stochastic variation in small samples. These findings indicate that presently we cannot reject the null hypothesis that maternal dominance rank is unrelated to birth sex ratios.
Collapse
Affiliation(s)
- Gillian R Brown
- Sub-Department of Animal Behaviour, Department of Zoology, University of Cambridge, Madingley, Cambridge CB3 8AA, United Kingdom
| | | |
Collapse
|
33
|
|
34
|
Johnson CN, Clinchy M, Taylor AC, Krebs CJ, Jarman PJ, Payne A, Ritchie EG. Adjustment of offspring sex ratios in relation to the availability of resources for philopatric offspring in the common brushtail possum. Proc Biol Sci 2001; 268:2001-5. [PMID: 11571046 PMCID: PMC1088841 DOI: 10.1098/rspb.2001.1723] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The local-resource-competition hypothesis predicts that where philopatric offspring compete for resources with their mothers, offspring sex ratios will be biased in favour of the dispersing sex. This should produce variation in sex ratios between populations in relation to differences in the availability of resources for philopatric offspring. However, previous tests of local resource competition in mammals have used indirect measures of resource availability and have focused on sex-ratio variation between species or individuals rather than between local populations. Here, we show that the availability of den sites predicts the offspring sex ratio in populations of the common brushtail possum. Female possums defend access to dens, and daughters, but not sons, occupy dens within their mother's range. However, the abundances of possums in our study areas were determined principally by food availability. Consequently, in food-rich areas with a high population density, the per-capita availability of dens was low, and the cost of having a daughter should have been high. This cost was positively correlated with male bias in the sex ratio at birth. Low per capita availability of dens was correlated with male bias in the sex ratio at birth.
Collapse
Affiliation(s)
- C N Johnson
- School of Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
| | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Strier KB. Population Viabilities and Conservation Implications for Muriquis (Brachyteles arachnoids) in Brazil's Atlantic Forest1. Biotropica 2000. [DOI: 10.1111/j.1744-7429.2000.tb00628.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
37
|
Abstract
Birth sex ratios of baboons in Gombe National Park, Tanzania, show an overall male bias of ca. 20%, but there is no obvious explanation for this trend. Individual females did not alter their sex ratios according to persistent levels of local resource competition. Sex ratios showed an unexpected relationship between age and rank: subordinate females had more sons when they were young; dominant females had more sons when they were old. The sex ratio of low-ranking females also varied with the severity of environmental conditions during pregnancy. Our findings suggest that mammalian sex ratios might be the product of more complex processes than is generally recognized or that sex-determining mechanisms impose sufficient constraints to prevent adaptive variation in all contexts.
Collapse
Affiliation(s)
- C Packer
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul 55108, USA.
| | | | | |
Collapse
|
38
|
Julliard R. Sex-specific dispersal in spatially varying environments leads to habitat-dependent evolutionary stable offspring sex ratios. Behav Ecol 2000. [DOI: 10.1093/beheco/11.4.421] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
39
|
Atsalis S. Spatial distribution and population composition of the brown mouse lemur (Microcebus rufus) in Ranomafana National Park, Madagascar, and its implications for social organization. Am J Primatol 2000; 51:61-78. [PMID: 10811440 DOI: 10.1002/(sici)1098-2345(200005)51:1<61::aid-ajp5>3.0.co;2-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Through a 16-mo mark-recapture trap study, I examined aspects of spatial distribution and population composition in the brown mouse lemur, Microcebus rufus, a 42 g nocturnal strepsirhine. The study took place in the rainforest of Ranomafana National Park in southeastern Madagascar. Sherman live traps were set monthly for a variable number of nights in a quasi-grid 50 m apart. Captured individuals were marked for future identification and released at site of capture. More males than females were captured overall (102 versus 72) and at 83% of trap sites. Trap sex ratio fluctuated significantly over the course of the study. It was particularly male-biased between June and August (3.9:1), when more previously uncaptured males than females (14 versus 6) entered the trap population. Some of these males remained in the trap population. Although the average number of individuals captured was not significantly different between the first four and last four months of the study, the composition of the population changed. The female population, however, changed less: 28.9% of all females captured in the first four months of the study were recaptured in the last four months, compared to 9.7% of males. It is suggested that the pattern of appearance of new individuals and disappearance of others, both predominantly male, may indicate migratory activity. Furthermore, an average of eight individuals were captured at each trap site (approximately 70% of traps captured more than five), suggesting a high degree of spatial overlap. The average number of male and female individuals captured in each trap (5.5 males versus 2.5 females), the average number of trap sites at which males and females were captured (3.6 versus 2.4), and the average number of captures for males and females (9.8 versus 5.7) all differed significantly between the sexes.
Collapse
Affiliation(s)
- S Atsalis
- Department of Cell and Molecular Biology, Northwestern University, Chicago, Illinois, USA.
| |
Collapse
|
40
|
Strier KB. Population Viabilities and Conservation Implications for Muriquis (Brachyteles arachnoides) in Brazil's Atlantic Forest1. Biotropica 2000. [DOI: 10.1646/0006-3606(2000)032[0903:pvacif]2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
41
|
Faust LJ, Thompson SD. Birth sex ratio in captive mammals: Patterns, biases, and the implications for management and conservation. Zoo Biol 2000. [DOI: 10.1002/(sici)1098-2361(2000)19:1<11::aid-zoo2>3.0.co;2-v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
42
|
Post E, Forchhammer MC, Stenseth NC, Langvatn R. Extrinsic Modification of Vertebrate Sex Ratios by Climatic Variation. Am Nat 1999; 154:194-204. [DOI: 10.1086/303224] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
43
|
|
44
|
Abstract
Biased sex ratios of young of birds and mammals clearly occur and may have an adaptive significance, but we rarely know the stage at which a bias is generated, or the mechanism. If a bias is generated prior to birth, studies of marsupials may be insightful because gestation is short and neonates are relatively undifferentiated. This study investigated whether biased sex ratios in Antechinus agilis are generated in the brief period between birth and the attachment of young to the mother's teats. When all young born, or just pouch young, or supernumerary young were considered, litters were strongly biased towards females (0.32 males), and there was no significant difference across the groups, so a bias is generated before birth in this species. Evidence from counts of corpora lutea suggests that embryo loss during gestation cannot account fully for the level of bias observed. Therefore, prefertilization mechanisms must contribute to the generation of sex-biased litters in this marsupial.
Collapse
Affiliation(s)
- M J Davison
- Department of Zoology, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
45
|
|
46
|
Perret M, Colas S. Manipulation of sex ratio at birth and maternal investment in female mouse lemurs (Microcebus murinus, Primates). Appl Anim Behav Sci 1997. [DOI: 10.1016/s0168-1591(96)01110-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
47
|
|
48
|
|
49
|
van Hooff J. The socio-ecology of sex ratio variation in primates: evolutionary deduction and empirical evidence. Appl Anim Behav Sci 1997. [DOI: 10.1016/s0168-1591(96)01112-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
50
|
Abstract
Young Seychelles warblers (
Acrocephalus sechellensis
) frequently remain in their natal territories as helpers. Helpers on low-quality territories (as measured by food availability) reduce their parents' future reproductive success, whereas helpers on high-quality territories increase their parents' future reproductive success, thereby improving their own indirect component of inclusive fitness. Helpers are mainly females, which remain longer in their natal territories than males. The Seychelles warbler shows extreme skews in sex ratios of offspring at six months of age, varying from mainly males on low-quality territories to mainly females on high-quality territories. It appears that breeding birds avoid having helpers on low-quality territories and gain helpers on high-quality territories, thereby increasing their reproductive success. There is evidence that the biased sex ratio is caused by biased production, and not because of biased mortality at younger ages: (i) cumulative mortality from the egg stage to the stage at six months of age is insufficient to generate a consistent deviation from sex ratio parity; (ii) all 30 nestlings produced by two pairs on low-quality territories survived to be sexed as sons, and all nestlings produced by two pairs on high-quality territories survived to be sexed as 17 daughters and one son; and (iii) in addition, breeding pairs that were transferred from low- to high-quality territories, switched from the production of male to female nestlings.
Collapse
|