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Reproductive timing as an explanation for skewed parentage assignment ratio in a bisexually philopatric population. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03233-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Betty EL, Stockin KA, Smith ANH, Bollard B, Orams MB, Murphy S. Sexual maturation in male long-finned pilot whales (Globicephala melas edwardii): defining indicators of sexual maturity. J Mammal 2019. [DOI: 10.1093/jmammal/gyz086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Male reproductive biology is described for the Southern Hemisphere long-finned pilot whale (Globicephala melas edwardii), a subspecies that regularly mass strands along the New Zealand coastline. Ten mass stranding events sampled over a 7-year period enabled assessments of key life history parameters. Sexual maturation in immature, maturing, and mature males was assessed using morphological data and histological examination of testicular tissue. Variation was observed in the age (11–15 years) and length (450–490 cm) at which individuals attained sexual maturity. Using Bayesian cumulative logit regression models, we estimated the average age and length at the attainment of sexual maturity to be 13.5 years and 472 cm, respectively. Combined testes weight, combined testes length, an index of testicular development (combined testes weight/combined testes length), and mean seminiferous tubule diameter were all good indicators of sexual maturity status. Combined testes length was the best nonhistological indicator, and all testicular measures were found to be better indicators of sexual maturation for G. m. edwardii than age or total body length. Sexual maturity was attained before physical maturity (> 40 years and 570 cm), and at a younger age and smaller body length than previously reported for Globicephala melas melas in the North Atlantic. Given the ease of collection, minimal processing, and applicability to suboptimal material collected from stranding events, future studies should assess the value of testicular size as an indicator of sexual maturity in pilot whales and other cetacean species. Estimates of the average age and length at sexual maturity for G. m. edwardii provided in this study may be used to inform population models required for conservation management of the subspecies, which is subject to high levels of stranding-related mortality.
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Affiliation(s)
- Emma L Betty
- School of Natural and Computational Sciences, College of Sciences, Massey University, Auckland, New Zealand
- School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Karen A Stockin
- School of Natural and Computational Sciences, College of Sciences, Massey University, Auckland, New Zealand
| | - Adam N H Smith
- School of Natural and Computational Sciences, College of Sciences, Massey University, Auckland, New Zealand
| | - Barbara Bollard
- School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Mark B Orams
- School of Sport and Recreation, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
- Sustainability Research Centre, University of the Sunshine Coast, Queensland, Australia
| | - Sinéad Murphy
- Marine and Freshwater Research Centre, Department of Natural Sciences, School of Science and Computing, Galway-Mayo Institute of Technology, Galway, Ireland
- Institute of Zoology, Zoological Society of London, London, United Kingdom
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Ebensperger LA, Correa LA, Ly Prieto Á, Pérez de Arce F, Abades S, Hayes LD. Multiple mating is linked to social setting and benefits the males in a communally rearing mammal. Behav Ecol 2019. [DOI: 10.1093/beheco/arz003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Individuals in social species may mate with multiple opposite-sex individuals, including members of the same or different social groups. This variation may be linked to genetic benefits, where multiple mating decreases risk of inbreeding. Multiple mating may also be constrained by the sociospatial setting through its effect on availability of mates. Because multiple mating with individuals from same or different groups may determine sex-specific fitness effects, we also examined how multiple mating modulates social benefits of females and males. We used 7 years of data on demography, social organization, and genetics of a natural population of the group-living and colonial rodent, Octodon degus, to determine how kin and sex composition within social groups, and spatial relations between these groups (i.e., colonial habits) influence multiple mating and its fitness consequences. Males (81.3%) and females (64.9%) produced offspring with multiple opposite-sex individuals within groups and with individuals of neighboring groups. Thus, polygynandry was the dominant mating system in the degu population examined. Multiple mating in degus was high when compared with estimates reported in other social mammals. Variation in female and male multiple mating was better explained by social setting through its effect on availability of potential mates rather than by benefits derived from decreasing risk of inbreeding. Finally, our study revealed how multiple mating enhances male, but not female reproductive success.
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Affiliation(s)
- Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Loreto A Correa
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Álvaro Ly Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Felipe Pérez de Arce
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Sebastian Abades
- GEMA Center for Genomics, Ecology and Environment, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biological and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
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Herzing DL, Augliere BN, Elliser CR, Green ML, Pack AA. Exodus! Large-scale displacement and social adjustments of resident Atlantic spotted dolphins (Stenella frontalis) in the Bahamas. PLoS One 2017; 12:e0180304. [PMID: 28792947 PMCID: PMC5549894 DOI: 10.1371/journal.pone.0180304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 06/13/2017] [Indexed: 11/18/2022] Open
Abstract
Over the last 20 years, significant habitat shifts have been documented in some populations of cetaceans. On Little Bahama Bank (LBB) there are sympatric communities of resident Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus), monitored since 1985. The size and social structure (three clusters: Northern, Central, Southern) have been stable among the spotted dolphin community with little immigration/emigration, even after large demographic losses (36%) following two major hurricanes in 2004. In 2013 an unprecedented exodus of over 50% (52 individuals) of the spotted dolphin community was documented. The entire Central cluster and a few Northern and Southern individuals relocated 161 km south to Great Bahama Bank (GBB), also home to two sympatric resident communities of spotted dolphins and bottlenose dolphins. During the late summer of 2013 and the summers of 2014 and 2015 both sites were regularly monitored but no former LBB dolphins returned to LBB. Uncharacteristic matriline splits were observed. Social analyses revealed random associations for those spotted dolphins and very little integration between spotted dolphins that moved to GBB (MGBB) and those dolphin resident to GBB (RGBB). Male alliances among spotted dolphins were present, with some altered patterns. On LBB, the operational sex ratio (OSR) was reduced (.40 to .25). OSR for MGBB and RGBB dolphins were similar (.45 and .43). A significant steady decrease in sea surface temperature and chlorophyll a (a proxy for plankton production) occurred on LBB leading up to this exodus. Similar trends were not present over the same period on GBB. The sudden large-scale shift of spotted dolphins from LBB to GBB in association with the gradual decline in certain environmental factors suggests that a possible "tipping point" was reached in prey availability. This study provides a unique view into social and genetic implications of large-scale displacement of stable dolphin communities.
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Affiliation(s)
- Denise L. Herzing
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | | | - Cindy R. Elliser
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Pacific Mammal Research, Anacortes, Washington, United States of America
| | - Michelle L. Green
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Department of Animal Science and Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Adam A. Pack
- Departments of Psychology and Biology, University of Hawaii at Hilo, Hilo, Hawaii, United States of America
- The Dolphin Institute, Hilo, Hawaii, United States of America
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Rathke EM, Berghänel A, Bissonnette A, Ostner J, Schülke O. Age-dependent change of coalitionary strategy in male Barbary macaques. Primate Biol 2017; 4:1-7. [PMID: 32110686 PMCID: PMC7041515 DOI: 10.5194/pb-4-1-2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 01/09/2017] [Indexed: 12/01/2022] Open
Abstract
Inter- and intra-specific variation in the propensity to form coalitions has
been explained by variation in the availability of suitable partners,
distribution of fighting ability, coalition profitability, and costs of
coordination. Male coalition formation can be an alternative reproductive
strategy to one-on-one competition to maximize male reproductive success.
Here we focus on age as a state variable to explain within-group variation in
individual propensity to form coalitions against other group members. We
specifically test the prediction that males conditionally switch from a solo
strategy for achievement of high mating success to a cooperative strategy
after reaching post-prime age in male Barbary macaques (Macaca sylvanus). We combined new observations with data collected in 2006 and 2008
on the same individuals from one captive group living in semi-natural
conditions at Affenberg Salem, Germany, and found that in all years males
between 5 and 13 years formed significantly fewer coalitions than males
14 years and older (post-prime). More importantly, we found those males that
aged into the post-prime phase to have switched their reproductive strategy
and to form significantly more coalitions in 2014 compared to 2008. These
first longitudinal data together with earlier cross-sectional analyses in
this and other primate species suggest that group-level measures of coalition
propensity may be strongly affected by the age composition of groups and that
male coalition formation can be a conditional reproductive strategy.
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Affiliation(s)
- Eva-Maria Rathke
- Department of Behavioral Ecology, Georg-August University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.,Cognitive Ethology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Andreas Berghänel
- Department of Behavioral Ecology, Georg-August University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.,Department of Anthropology, University of New Mexico, MSC01-1040, Anthropology, 1, Albuquerque, NM 87131, USA
| | - Annie Bissonnette
- Department of Behavioral Ecology, Georg-August University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.,Anthropological Institute and Museum, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Julia Ostner
- Department of Behavioral Ecology, Georg-August University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.,Primate Social Evolution Group, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Oliver Schülke
- Department of Behavioral Ecology, Georg-August University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.,Primate Social Evolution Group, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
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Green ML, Herzing DL, Baldwin JD. Molecular assessment of mating strategies in a population of Atlantic spotted dolphins. PLoS One 2015; 10:e0118227. [PMID: 25692972 PMCID: PMC4334488 DOI: 10.1371/journal.pone.0118227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 01/09/2015] [Indexed: 11/19/2022] Open
Abstract
Similar to other small cetacean species, Atlantic spotted dolphins (Stenella frontalis) have been the object of concentrated behavioral study. Although mating and courtship behaviors occur often and the social structure of the population is well-studied, the genetic mating system of the species is unknown. To assess the genetic mating system, we genotyped females and their progeny at ten microsatellite loci. Genotype analysis provided estimates of the minimum number of male sires necessary to account for the allelic diversity observed among the progeny. Using the estimates of male sires, we determined whether females mated with the same or different males during independent estrus events. Using Gerud2.0, a minimum of two males was necessary to account for the genetic variation seen among progeny arrays of all tested females. ML-Relate assigned the most likely relationship between offspring pairs; half or full sibling. Relationship analysis supported the conservative male estimates of Gerud2.0 but in some cases, half or full sibling relationships between offspring could not be fully resolved. Integrating the results from Gerud2.0, ML-Relate with previous observational and paternity data, we constructed two-, three-, and four-male pedigree models for each genotyped female. Because increased genetic diversity of offspring may explain multi-male mating, we assessed the internal genetic relatedness of each offspring's genotype to determine whether parent pairs of offspring were closely related. We found varying levels of internal relatedness ranging from unrelated to closely related (range -0.136-0.321). Because there are several hypothesized explanations for multi-male mating, we assessed our data to determine the most plausible explanation for multi-male mating in our study system. Our study indicated females may benefit from mating with multiple males by passing genes for long-term viability to their young.
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Affiliation(s)
- Michelle L. Green
- Department of Biology, Florida Atlantic University, 3200 College Avenue, Davie, Florida, 33314, United States of America
| | - Denise L. Herzing
- Wild Dolphin Project, P.O. Box 8436, Jupiter, Florida, 33468, United States of America
- Department of Biology, Department of Psychology, Florida Atlantic University, 777 Glades Road, Boca Raton, Florida, 33431, United States of America
| | - John D. Baldwin
- Department of Biology, Florida Atlantic University, 3200 College Avenue, Davie, Florida, 33314, United States of America
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