51
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Sprayberry K, Tylan C, Owen DAS, Macleod KJ, Sheriff MJ, Langkilde T. History of predator exposure affects cell-mediated immunity in female eastern fence lizards, Sceloporus undulatus (Squamata: Phrynosomatidae). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Abstract
On exposure to stressors, energy is diverted from non-urgent functions towards those important for immediate survival. The degree and nature of reallocation may be affected by the evolutionary history of the animal. The eastern fence lizard (Sceloporus undulatus) coexists in parts of its range with invasive fire ants (Solenopsis invicta), which attack and wound lizards and elevate stress-relevant hormones (corticosterone), whereas other populations have never been exposed to fire ants. We examined how a history of fire ant invasion affected the immune response in female lizards after exposure to exogenous corticosterone (mimicking exposure to a stressor) during gestation (dosing regimens differed among corticosterone-exposed lizards owing to the constraints of the original studies, but we found no evidence that this affected the outcome of the present study). A history of exposure to predatory stressors (fire ants) and corticosterone treatment affected cell-mediated immunity. Lizards from fire ant-invaded sites had a reduced immune response compared with those from uninvaded sites. Corticosterone treatment had no effect on the immune response of lizards from invaded sites but reduced the immune response of lizards from uninvaded sites. This suggests that an evolutionary history of exposure to wounding alters the immune response to corticosterone. Future work on how the immune system responds to environmental threats will be informative for the prediction and management of these threats.
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Affiliation(s)
- Kristen Sprayberry
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, USA
| | - Catherine Tylan
- Department of Biology, The Pennsylvania State University, University Park, USA
| | - Dustin A S Owen
- Department of Biology, The Pennsylvania State University, University Park, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, USA
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, USA
| | - Kirsty J Macleod
- Department of Biology, The Pennsylvania State University, University Park, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, USA
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, USA
| | - Michael J Sheriff
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, USA
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, USA
| | - Tracy Langkilde
- Department of Biology, The Pennsylvania State University, University Park, USA
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, USA
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52
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Impact of continuous predator threat on telomere dynamics in parent and nestling pied flycatchers. Oecologia 2019; 191:757-766. [PMID: 31612326 PMCID: PMC6853860 DOI: 10.1007/s00442-019-04529-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 10/03/2019] [Indexed: 11/03/2022]
Abstract
In addition to direct mortality, predators can have indirect effects on prey populations by affecting prey behaviour or physiology. For example, predator presence can increase stress hormone levels, which can have physiological costs. Stress exposure accelerates the shortening of telomeres (i.e. the protective caps of chromosomes) and shorter telomeres have been linked to increased mortality risk. However, the effect of perceived predation risk on telomeres is not known. We investigated the effects of continuous predator threat (nesting Eurasian pygmy owl Glaucidium passerinum) on telomere dynamics of both adult and partially cross-fostered nestling pied flycatchers (Ficedula hypoleuca) in the wild. Females nesting at owl-inhabited sites showed impaired telomere maintenance between incubation and chick rearing compared to controls, and both males and females ended up with shorter telomeres at owl-inhabited sites in the end of chick rearing. On the contrary, both original and cross-fostered chicks reared in owl sites had consistently longer telomeres during growth than chicks reared at control sites. Thus, predation risk may cause a long-term cost in terms of telomeres for parents but not for their offspring. Predators may therefore affect telomere dynamics of their preys, which could have implications for their ageing rate and consequently for population dynamics.
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53
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Moore MP, Whiteman HH, Martin RA. A mother’s legacy: the strength of maternal effects in animal populations. Ecol Lett 2019; 22:1620-1628. [DOI: 10.1111/ele.13351] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 06/28/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Michael P. Moore
- Department of Biology Case Western Reserve University Cleveland OH44106
- Watershed Studies Institute and Department of Biological Sciences Murray State University Murray KY42071
| | - Howard H. Whiteman
- Watershed Studies Institute and Department of Biological Sciences Murray State University Murray KY42071
| | - Ryan A. Martin
- Department of Biology Case Western Reserve University Cleveland OH44106
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54
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Guindre-Parker S, Mcadam AG, van Kesteren F, Palme R, Boonstra R, Boutin S, Lane JE, Dantzer B. Individual variation in phenotypic plasticity of the stress axis. Biol Lett 2019; 15:20190260. [PMID: 31337294 DOI: 10.1098/rsbl.2019.0260] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Phenotypic plasticity-one individual's capacity for phenotypic variation under different environments-is critical for organisms facing fluctuating conditions within their lifetime. North American red squirrels (Tamiasciurus hudsonicus) experience drastic among-year fluctuations in conspecific density. This shapes juvenile competition over vacant territories and overwinter survival. To help young cope with competition at high densities, mothers can increase offspring growth rates via a glucocorticoid-mediated maternal effect. However, this effect is only adaptive under high densities, and faster growth often comes at a cost to longevity. While red squirrels can adjust hormones in response to fluctuating density, the degree to which mothers differ in glucocorticoid plasticity across changing densities remains unknown. Findings from our reaction norm approach revealed significant individual variation not only in a female red squirrel's mean endocrine phenotype but also in endocrine plasticity in response to changes in local density. Future work on proximate and ultimate drivers of variation in endocrine plasticity and maternal effects is needed, particularly in free-living animals experiencing fluctuating environments.
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Affiliation(s)
- Sarah Guindre-Parker
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.,Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| | - Andrew G Mcadam
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | | | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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55
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Hair cortisol concentration in Siberian flying squirrels is unrelated to landscape and social factors. Naturwissenschaften 2019; 106:29. [DOI: 10.1007/s00114-019-1624-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 05/06/2019] [Accepted: 05/11/2019] [Indexed: 12/13/2022]
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56
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The effects of embryonic experience with predation risk vary across a wave exposure gradient. Ecosphere 2019. [DOI: 10.1002/ecs2.2676] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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57
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Edwards AM, Cameron EZ, Wapstra E, McEvoy J. Maternal effects obscure condition-dependent sex allocation in changing environments. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181885. [PMID: 31183124 PMCID: PMC6502394 DOI: 10.1098/rsos.181885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/05/2019] [Indexed: 06/09/2023]
Abstract
Climate change increases environmental fluctuations which thereby impact population demography. Species with temperature-dependent sex determination may experience more extreme sex ratio skews, but this has not been considered in species with chromosomally determined sex. However, anticipatory maternal effects cause lifelong physiological changes impacting sex ratios. Here we show, in mice, that more sons were born to mothers in good condition when their breeding environment matched their gestational environment, consistent with theoretical predictions, but mothers in mismatched environments have no condition-sex ratio relationship. Thus, the predicted effect of condition on sex ratio was obscured by maternal effects when the environment changed. This may explain extreme sex ratio skews in reintroduced or translocated populations, and sex ratio skews may become more common and less predictable with accelerating environmental change.
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Affiliation(s)
- A. M. Edwards
- Department of Ecology, Environment and Evolution, La Trobe University, Bundoora, Victoria 3086, Australia
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - E. Z. Cameron
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - E. Wapstra
- Department of Ecology, Environment and Evolution, La Trobe University, Bundoora, Victoria 3086, Australia
| | - J. McEvoy
- Department of Ecology, Environment and Evolution, La Trobe University, Bundoora, Victoria 3086, Australia
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58
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59
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Crawford DA, Cherry MJ, Kelly BD, Garrison EP, Shindle DB, Conner LM, Chandler RB, Miller KV. Chronology of reproductive investment determines predation risk aversion in a felid-ungulate system. Ecol Evol 2019; 9:3264-3275. [PMID: 30962891 PMCID: PMC6434540 DOI: 10.1002/ece3.4947] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/20/2018] [Accepted: 12/21/2018] [Indexed: 01/01/2023] Open
Abstract
Fear of predators can behaviorally mediate prey population dynamics, particularly when predation risk influences reproductive investment. However, the costs of reproductive investment may mitigate predation risk aversion relative to periods when the link between reproductive output and prey behavior is weaker.We posit that intensity of reproductive investment in ungulates may predict their response to predation risk such that the sexes increase risk exposure during biological seasons that are pivotal to reproductive success, such as the fawn-rearing and breeding seasons for females and males, respectively.We examined the activity patterns of sympatric white-tailed deer (Odocoileus virginianus), a sexually segregated polygynous ungulate, and Florida panthers (Puma concolor coryi) in the context of the "risky times - risky places hypothesis" and the reproductive strategy hypothesis. We compared detection rates and diel activity overlap of both species using motion-triggered camera traps positioned on (n = 120) and off (n = 60) anthropogenic trails across five reproductive seasons.Florida panthers were nocturnal and primarily observed on-trail providing an experimental framework with risky times and risky places. Contrary to studies in other taxa inversely correlating prey reproductive investment to predation risk, the sexes of deer were more risk prone during sex-specific seasons associated with intense reproductive investment.Our results suggest spatiotemporally variable predation risk influences sex-specific behavioral decision-making in deer such that reproductive success is maximized.
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Affiliation(s)
- Daniel A. Crawford
- Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensGeorgia
| | - Michael J. Cherry
- College of Natural Resources and EnvironmentVirginia Polytechnic Institute and State UniversityBlacksburgVirginia
| | - Brian D. Kelly
- Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensGeorgia
| | - Elina P. Garrison
- Fish and Wildlife Research InstituteFlorida Fish and Wildlife Conservation CommissionGainesvilleFlorida
| | | | | | - Richard B. Chandler
- Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensGeorgia
| | - Karl V. Miller
- Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensGeorgia
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60
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Bairos-Novak KR, Crane AL, Chivers DP, Ferrari MCO. Better the devil you know? How familiarity and kinship affect prey responses to disturbance cues. Behav Ecol 2018. [DOI: 10.1093/beheco/ary184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Adam L Crane
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Douglas P Chivers
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Maud C O Ferrari
- Department of Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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61
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Schell CJ, Young JK, Lonsdorf EV, Santymire RM, Mateo JM. Parental habituation to human disturbance over time reduces fear of humans in coyote offspring. Ecol Evol 2018; 8:12965-12980. [PMID: 30619597 PMCID: PMC6308887 DOI: 10.1002/ece3.4741] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/10/2018] [Accepted: 10/24/2018] [Indexed: 12/18/2022] Open
Abstract
A fundamental tenet of maternal effects assumes that maternal variance over time should have discordant consequences for offspring traits across litters. Yet, seldom are parents observed across multiple reproductive bouts, with few studies considering anthropogenic disturbances as an ecological driver of maternal effects. We observed captive coyote (Canis latrans) pairs over two successive litters to determine whether among‐litter differences in behavior (i.e., risk‐taking) and hormones (i.e., cortisol and testosterone) corresponded with parental plasticity in habituation. Thus, we explicitly test the hypothesis that accumulating experiences of anthropogenic disturbance reduces parental fear across reproductive bouts, which should have disparate phenotypic consequences for first‐ and second‐litter offspring. To quantify risk‐taking behavior, we used foraging assays from 5–15 weeks of age with a human observer present as a proxy for human disturbance. At 5, 10, and 15 weeks of age, we collected shaved hair to quantify pup hormone levels. We then used a quantitative genetic approach to estimate heritability, repeatability, and between‐trait correlations. We found that parents were riskier (i.e., foraged more frequently) with their second versus first litters, supporting our prediction that parents become increasingly habituated over time. Second‐litter pups were also less risk‐averse than their first‐litter siblings. Heritability for all traits did not differ from zero (0.001–0.018); however, we found moderate support for repeatability in all observed traits (r = 0.085–0.421). Lastly, we found evidence of positive phenotypic and cohort correlations among pup traits, implying that cohort identity (i.e., common environment) contributes to the development of phenotypic syndromes in coyote pups. Our results suggest that parental habituation may be an ecological cue for offspring to reduce their fear response, thus emphasizing the role of parental plasticity in shaping their pups’ behavioral and hormonal responses toward humans.
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Affiliation(s)
- Christopher J Schell
- Committee on Evolutionary Biology University of Chicago Chicago Illinois.,School of Interdisciplinary Arts and Sciences University of Washington Tacoma Tacoma Washington
| | - Julie K Young
- USDA-WS-NWRC Predator Research Facility, Department of Wildland Resources Utah State University Logan Utah
| | | | - Rachel M Santymire
- Committee on Evolutionary Biology University of Chicago Chicago Illinois.,Conservation and Science Department Lincoln Park Zoo Chicago Illinois
| | - Jill M Mateo
- Committee on Evolutionary Biology University of Chicago Chicago Illinois
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62
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Gartstein MA, Skinner MK. Prenatal influences on temperament development: The role of environmental epigenetics. Dev Psychopathol 2018; 30:1269-1303. [PMID: 29229018 PMCID: PMC5997513 DOI: 10.1017/s0954579417001730] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This review summarizes current knowledge and outlines future directions relevant to questions concerning environmental epigenetics and the processes that contribute to temperament development. Links between prenatal adversity, epigenetic programming, and early manifestations of temperament are important in their own right, also informing our understanding of biological foundations for social-emotional development. In addition, infant temperament attributes represent key etiological factors in the onset of developmental psychopathology, and studies elucidating their prenatal foundations expand our understanding of developmental origins of health and disease. Prenatal adversity can take many forms, and this overview is focused on the environmental effects of stress, toxicants, substance use/psychotropic medication, and nutrition. Dysregulation associated with attention-deficit/hyperactivity-disruptive disorders was noted in the context of maternal substance use and toxicant exposures during gestation, as well as stress. Although these links can be made based on the existing literature, currently few studies directly connect environmental influences, epigenetic programming, and changes in brain development/behavior. The chain of events starting with environmental inputs and resulting in alterations to gene expression, physiology, and behavior of the organism is driven by epigenetics. Epigenetics provides the molecular mechanism of how environmental factors impact development and subsequent health and disease, including early brain and temperament development.
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Affiliation(s)
- Maria A. Gartstein
- Department of Psychology, Washington State University, Pullman, WA-99164-4820, USA
| | - Michael K. Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA-99164-4236, USA
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63
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Abolins-Abols M, Hanauer RE, Rosvall KA, Peterson MP, Ketterson ED. The effect of chronic and acute stressors, and their interaction, on testes function: an experimental test during testicular recrudescence. J Exp Biol 2018; 221:jeb180869. [PMID: 29997161 PMCID: PMC6919650 DOI: 10.1242/jeb.180869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/29/2018] [Indexed: 01/21/2023]
Abstract
Organisms are expected to invest less in reproduction in response to a stressor, but theory predicts that this effect should depend on the frequency and duration of stressors in the environment. Here, we investigated how an acute stressor affected testes function in a songbird, and how chronic stressors influenced the acute stress response. We exposed male dark-eyed juncos (Junco hyemalis) either to chronic or minimal (control) disturbance during testicular recrudescence, after which we measured baseline testosterone, testosterone after an acute handling stressor, and capacity to produce testosterone after hormonal stimulation. In a 2×2 design, we then killed males from the two chronic treatment groups either immediately or after an acute stressor to investigate the effect of long- and short-term stressors on the testicular transcriptome. We found that chronically disturbed birds had marginally lower baseline testosterone. The acute stressor suppressed testosterone in control birds, but not in the chronic disturbance group. The ability to elevate testosterone did not differ between the chronic treatments. Surprisingly, chronic disturbance had a weak effect on the testicular transcriptome, and did not affect the transcriptomic response to the acute stressor. The acute stressor, on the other hand, upregulated the cellular stress response and affected expression of genes associated with hormonal stress response. Overall, we show that testicular function is sensitive to acute stressors but surprisingly robust to long-term stressors, and that chronic disturbance attenuates the decrease in testosterone in response to an acute stressor.
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Affiliation(s)
- Mikus Abolins-Abols
- 505 S Goodwin Ave, Department of Animal Biology, School of Integrative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- 1001 E. 3rd St., Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Rachel E Hanauer
- 1001 E. 3rd St., Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Kimberly A Rosvall
- 1001 E. 3rd St., Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Mark P Peterson
- 1800 Technology Dr. NE, Life-Science Innovations, Willmar, MN 56201, USA
| | - Ellen D Ketterson
- 1001 E. 3rd St., Department of Biology, Indiana University, Bloomington, IN 47405, USA
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64
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65
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Ensminger DC, Langkilde T, Owen DAS, MacLeod KJ, Sheriff MJ. Maternal stress alters the phenotype of the mother, her eggs and her offspring in a wild-caught lizard. J Anim Ecol 2018; 87:1685-1697. [PMID: 30074248 DOI: 10.1111/1365-2656.12891] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/22/2018] [Indexed: 01/05/2023]
Abstract
While biomedical researchers have long appreciated the influence of maternally derived glucocorticoids (GCs) on offspring phenotype, ecologists have only recently begun exploring its impact in wild animals. Interpreting biomedical findings within an ecological context has posited that maternal stress, mediated by elevations of maternal GCs, may play an adaptive role preparing offspring for a stressful or rigorous environment. Yet, the influence of maternal stress on offspring phenotype has been little studied in wild animals. We experimentally elevated GCs to ecologically relevant levels (mimicking increases in maternal stress hormones following a nonlethal predator encounter, a heat challenge, or a chasing or confinement stressor) in female eastern fence lizards Sceloporus undulatus during gestation. We tested the hypothesis that maternally derived stress hormones themselves are sufficient to alter offspring phenotype. Specifically, we examined the effects of experimentally elevated maternal GCs on fitness-relevant traits of the mother, her eggs and her subsequent offspring. We found that daily maternal GC elevation: (a) increased maternal antipredator behaviours and postlaying glucose levels; (b) had no effect on egg morphology or caloric value, but altered yolk hormone (elevated GC) and nutrient content; and (c) altered offspring phenotype including stress-relevant physiology, morphology and behaviour. These findings reveal that maternally derived GCs alone can alter offspring phenotype in a wild animal, changes that may be mediated via maternal behaviour, and egg hormone and nutrient content. Understanding the ecological consequences of these effects under different environmental conditions will be critical for determining the adaptive significance of elevated maternal GCs for offspring.
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Affiliation(s)
- David C Ensminger
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Tracy Langkilde
- Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Dustin A S Owen
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Kirsty J MacLeod
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Michael J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
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66
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Sheriff MJ, Dantzer B, Love OP, Orrock JL. Error management theory and the adaptive significance of transgenerational maternal-stress effects on offspring phenotype. Ecol Evol 2018; 8:6473-6482. [PMID: 30038749 PMCID: PMC6053571 DOI: 10.1002/ece3.4074] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 02/22/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022] Open
Abstract
It is well established that circulating maternal stress hormones (glucocorticoids, GCs) can alter offspring phenotype. There is also a growing body of empirical work, within ecology and evolution, indicating that maternal GCs link the environment experienced by the mother during gestation with changes in offspring phenotype. These changes are considered to be adaptive if the maternal environment matches the offspring's environment and maladaptive if it does not. While these ideas are conceptually sound, we lack a testable framework that can be used to investigate the fitness costs and benefits of altered offspring phenotypes across relevant future environments. We present error management theory as the foundation for a framework that can be used to assess the adaptive potential of maternal stress hormones on offspring phenotype across relevant postnatal scenarios. To encourage rigorous testing of our framework, we provide field-testable hypotheses regarding the potential adaptive role of maternal stress across a diverse array of taxa and life histories, as well as suggestions regarding how our framework might provide insight into past, present, and future research. This perspective provides an informed lens through which to design and interpret experiments on the effects of maternal stress, provides a framework for predicting and testing variation in maternal stress across and within taxa, and also highlights how rapid environmental change that induces maternal stress may lead to evolutionary traps.
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Affiliation(s)
- Michael J. Sheriff
- Department of Ecosystem Science and ManagementHuck Institute of the Life SciencesPennsylvania State UniversityUniversity ParkPennsylvania
| | - Ben Dantzer
- Departments of Psychology, Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichigan
| | - Oliver P. Love
- Department of Biological SciencesUniversity of WindsorWindsorONCanada
| | - John L. Orrock
- Department of Integrative BiologyUniversity of WisconsinMadisonWisconsin
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67
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Rattenborg NC, de la Iglesia HO, Kempenaers B, Lesku JA, Meerlo P, Scriba MF. Sleep research goes wild: new methods and approaches to investigate the ecology, evolution and functions of sleep. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0251. [PMID: 28993495 DOI: 10.1098/rstb.2016.0251] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 11/12/2022] Open
Abstract
Despite being a prominent aspect of animal life, sleep and its functions remain poorly understood. As with any biological process, the functions of sleep can only be fully understood when examined in the ecological context in which they evolved. Owing to technological constraints, until recently, sleep has primarily been examined in the artificial laboratory environment. However, new tools are enabling researchers to study sleep behaviour and neurophysiology in the wild. Here, we summarize the various methods that have enabled sleep researchers to go wild, their strengths and weaknesses, and the discoveries resulting from these first steps outside the laboratory. The initial studies to 'go wild' have revealed a wealth of interindividual variation in sleep, and shown that sleep duration is not even fixed within an individual, but instead varies in response to an assortment of ecological demands. Determining the costs and benefits of this inter- and intraindividual variation in sleep may reveal clues to the functions of sleep. Perhaps the greatest surprise from these initial studies is that the reduction in neurobehavioural performance resulting from sleep loss demonstrated in the laboratory is not an obligatory outcome of reduced sleep in the wild.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'.
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Affiliation(s)
- Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | | | - Bart Kempenaers
- Department of Behavioral Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 Groningen, The Netherlands
| | - Madeleine F Scriba
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
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68
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Burness G, Moher D, Ben-Ezra N, Kelly RJ, Hasselquist D, Chin EH. Maternal immunization increases nestling energy expenditure, immune function, and fledging success in a passerine bird. Biol Open 2018; 7:7/4/bio028803. [PMID: 29618466 PMCID: PMC5936053 DOI: 10.1242/bio.028803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Female birds transfer maternally derived antibodies (matAb) to their nestlings, via the egg yolk. These antibodies are thought to provide passive protection, and allow nestlings to avoid the costs associated with mounting an innate immune response. To test whether there is an energetic benefit to nestlings from receiving matAb, we challenged adult female tree swallows (Tachycineta bicolor) prior to clutch initiation with either lipopolysaccharide (LPS) or saline (Control). Following hatching, one half of each female's nestlings were immunized on day 8 post-hatch with LPS or saline, and the 4-h post-immunization nestling metabolic rate (MR) was measured. There was no difference in either LPS-reactive antibodies or total Ig levels between offspring of immunized and non-immunized mothers on day 6 or 14 post-hatch, possibly reflecting a relatively short half-life of matAbs in altricial birds. Additionally, we found no evidence that nestlings from LPS-immunized mothers could avoid the growth suppression that may result from activation of an inflammatory response. Unexpectedly, we found that control nestlings from LPS mothers had higher resting MR than control nestlings of control mothers. We attribute the increased MR to the costs associated with a general non-specific enhancement of immune function in nestlings from LPS-immunized mothers. Consistent with enhanced immune function, nestlings of immunized mothers had a more robust inflammatory response to phytohaemagglutinin and higher fledging success. Our results suggest that maternal antigen exposure pre-laying can result in increased fitness for both mothers and offspring, depending on food availability. Summary: Exposure of female birds to a simulated pathogen prior to egg laying increases the metabolic rate, immune function, and fledging success of her nestlings.
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Affiliation(s)
- Gary Burness
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Deanna Moher
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Noah Ben-Ezra
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Ryan J Kelly
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | | | - Eunice H Chin
- Environmental and Life Science Graduate Program, Trent University, Peterborough, Ontario K9L 0G2, Canada
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69
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Bairos-Novak KR, Ryan CP, Freeman AR, Anderson WG, Hare JF. Like mother, like daughter: heritability of female Richardson's ground squirrel Urocitellus richardsonii cortisol stress responses. Curr Zool 2018; 64:153-163. [PMID: 30402055 PMCID: PMC5905375 DOI: 10.1093/cz/zox014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/22/2017] [Indexed: 11/16/2022] Open
Abstract
Activation of the hypothalamic-pituitary-adrenal (HPA) axis liberates glucocorticoids, which provides an acute indication of an individual's response to stressors. The heritability of the stress response in wild mammals, however, remains poorly documented. We quantified the cortisol stress response of female Richardson's ground squirrels (RGSs) to handling and physical restraint, testing for: (1) the effects of individual age, time of day, and sample latency; (2) repeatability within individuals; (3) narrow-sense heritability; and (4) differences among individuals owing to potential genetic and/or environmental effects. We detected a positive linear relationship between baseline plasma cortisol (BL-cortisol) concentration and stress-induced plasma cortisol (SI-cortisol) concentration that defined each individual's cortisol stress response. BL-cortisol, SI-cortisol, and stress response did not differ according to the time the sample was taken, or by subject age. Cortisol stress response was highly repeatable within individuals, had a mother-offspring heritability of h 2 = 0.40 ± 0.24 (mean ± SE), full-sibling heritability ofh FS 2 = 0.37 ± 0.71 , and half-sibling heritability ofh HS 2 = 0.75 ± 1.41 . Stress responses of sibling groups, immediate-family groups, and squirrels within a given area did not differ, whereas those of individuals from more distantly related matrilines did. Our results highlight the natural variability in HPA axis reactivity among individuals by quantifying both BL- and SI-cortisol levels, demonstrate partial heritability of the stress response that is not attributable to environmental variation, and suggest that at least part of an individual's stress response can be accounted for by differences in matrilineal history.
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Affiliation(s)
- Kevin R Bairos-Novak
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
- Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 Saskatchewan, Canada
| | - Calen P Ryan
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
- Department of Anthropology, Northwestern University, Evanston, 60208 Illinois, USA
| | - Angela R Freeman
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
- Department of Biological Sciences, Kent State University, Kent, 44242 Ohio, USA
| | - W Gary Anderson
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - James F Hare
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
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70
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Tóth Z, Hettyey A. Egg-laying environment modulates offspring responses to predation risk in an amphibian. J Evol Biol 2018; 31:710-721. [PMID: 29485239 DOI: 10.1111/jeb.13258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/18/2018] [Accepted: 02/15/2018] [Indexed: 11/29/2022]
Abstract
Predator-induced plasticity has been in the focus of evolutionary ecological research in the last decades, but the consequences of temporal variation in the presence of cues predicting offspring environment have remained controversial. This is partly due to the fact that the role of early environmental effects has scarcely been scrutinized in this context while also controlling for potential maternal effects. In this study, we investigated how past environmental conditions, that is different combinations of risky or safe adult (prenatal) and oviposition (early post-natal) environments, affected offspring's plastic responses in hatching time and locomotor activity to predation risk during development in the smooth newt (Lissotriton vulgaris). We found that females did not adjust their reproductive investment to the perceived level of risk in the adult environment, and this prenatal environment had generally negligible effect on offspring phenotype. However, when predator cues were absent during oviposition, larvae raised in the presence of predator cues delayed their hatching and exhibited a decreased activity compared to control larvae developing without predator cues, which responses are advantageous when predators pose a threat to hatched larvae. In the presence of predator cues during oviposition, the difference in hatching time persisted, but the difference in general locomotor activity disappeared between risk-exposed and control larvae. Our findings provide clear experimental evidence that fine-scale temporal variation in a predictive cue during and after egg-laying interactively affects offspring phenotype, and highlight the importance of the early post-natal environment, which may exert a substantial influence on progeny's phenotype also under natural conditions.
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Affiliation(s)
- Zoltán Tóth
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
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71
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Thayer ZM, Wilson MA, Kim AW, Jaeggi AV. Impact of prenatal stress on offspring glucocorticoid levels: A phylogenetic meta-analysis across 14 vertebrate species. Sci Rep 2018; 8:4942. [PMID: 29563562 PMCID: PMC5862967 DOI: 10.1038/s41598-018-23169-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 03/07/2018] [Indexed: 01/06/2023] Open
Abstract
Prenatal exposure to maternal stress is commonly associated with variation in Hypothalamic Pituitary Adrenal (HPA)-axis functioning in offspring. However, the strength or consistency of this response has never been empirically evaluated across vertebrate species. Here we meta-analyzed 114 results from 39 studies across 14 vertebrate species using Bayesian phylogenetic mixed-effects models. We found a positive overall effect of prenatal stress on offspring glucocorticoids (d' = 0.43) though the 95% Highest Posterior Density Interval overlapped with 0 (-0.16-0.95). Meta-regressions of potential moderators highlighted that phylogeny and life history variables predicted relatively little variation in effect size. Experimental studies (d' = 0.64) produced stronger effects than observational ones (d' = -0.01), while prenatal stress affected glucocorticoid recovery following offspring stress exposure more strongly (d' = 0.75) than baseline levels (d' = 0.48) or glucocorticoid peak response (d' = 0.36). These findings are consistent with the argument that HPA-axis sensitivity to prenatal stress is evolutionarily ancient and occurs regardless of a species' overall life history strategy. These effects may therefore be especially important for mediating intra-specific life-history variation. In addition, these findings suggest that animal models of prenatal HPA-axis programming may be appropriate for studying similar effects in humans.
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Affiliation(s)
- Zaneta M Thayer
- Department of Anthropology, Dartmouth College, New Hampshire, USA.
| | - Meredith A Wilson
- Department of Anthropology, University of Illinois Urbana-Champaign, Illinois, USA
| | - Andrew W Kim
- Department of Anthropology, Northwestern University, Illinois, USA
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72
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Sheriff MJ, Bell A, Boonstra R, Dantzer B, Lavergne SG, McGhee KE, MacLeod KJ, Winandy L, Zimmer C, Love OP. Integrating Ecological and Evolutionary Context in the Study of Maternal Stress. Integr Comp Biol 2018; 57:437-449. [PMID: 28957523 DOI: 10.1093/icb/icx105] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Maternal stress can prenatally influence offspring phenotypes and there are an increasing number of ecological studies that are bringing to bear biomedical findings to natural systems. This is resulting in a shift from the perspective that maternal stress is unanimously costly, to one in which maternal stress may be beneficial to offspring. However, this adaptive perspective is in its infancy with much progress to still be made in understanding the role of maternal stress in natural systems. Our aim is to emphasize the importance of the ecological and evolutionary context within which adaptive hypotheses of maternal stress can be evaluated. We present five primary research areas where we think future research can make substantial progress: (1) understanding maternal and offspring control mechanisms that modulate exposure between maternal stress and subsequent offspring phenotype response; (2) understanding the dynamic nature of the interaction between mothers and their environment; (3) integrating offspring phenotypic responses and measuring both maternal and offspring fitness outcomes under real-life (either free-living or semi-natural) conditions; (4) empirically testing these fitness outcomes across relevant spatial and temporal environmental contexts (both pre- and post-natal environments); (5) examining the role of maternal stress effects in human-altered environments-i.e., do they limit or enhance fitness. To make progress, it is critical to understand the role of maternal stress in an ecological context and to do that, we must integrate across physiology, behavior, genetics, and evolution.
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Affiliation(s)
- Michael J Sheriff
- Department of Ecosystem Science and Management, Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Alison Bell
- School of Integrative Biology, Program in Neuroscience, and Program in Ecology, Evolution and Conservation Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana Champaign, IL 61821, USA
| | - Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Ben Dantzer
- Department of Psychology, and Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sophia G Lavergne
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Katie E McGhee
- Department of Biology, the University of the South, Sewanee, TN 37383, USA
| | - Kirsty J MacLeod
- Department of Ecosystem Science and Management, Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, PA 16802, USA
| | - Laurane Winandy
- CNRS, Université Toulouse 3 Paul Sabatier, ENFA, UMR5174 (Laboratoire Évolution and Diversité Biologique), 31077 Toulouse, France.,CNRS, UMR5321, Station d'Ecologie Théorique et Expérimentale, 09200 Moulis, France
| | - Cedric Zimmer
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Oliver P Love
- Department of Biological Sciences, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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73
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Donelan SC, Trussell GC. Parental and embryonic experiences with predation risk affect prey offspring behaviour and performance. Proc Biol Sci 2018; 285:20180034. [PMID: 29540520 PMCID: PMC5879633 DOI: 10.1098/rspb.2018.0034] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/16/2018] [Indexed: 11/12/2022] Open
Abstract
Because phenotypic plasticity can operate both within and between generations, phenotypic outcomes are often shaped by a complex history of environmental signals. For example, parental and embryonic experiences with predation risk can both independently and interactively influence prey offspring traits early in their life. Parental and embryonic risk experiences can also independently shape offspring phenotypes throughout an offspring's ontogeny, but the persistence of their interactive effects throughout offspring ontogeny is unknown. We examined the effects of parental and embryonic experiences with predation risk on the response of 1-year-old prey (the carnivorous snail, Nucella lapillus) offspring to current predation risk. We found that parental and embryonic risk experiences had largely independent effects on offspring performance and that these effects were context dependent. Parental experience with risk had strong impacts on multiple offspring traits in the presence of current risk that generally improved offspring performance under risk, but embryonic risk experience had relatively weaker effects and only operated in the absence of current risk to reduce offspring growth. These results illustrate that past environmental experiences can dynamically shape organism phenotypes across ontogeny and that attention to these effects is key to a better understanding of predator/prey dynamics in natural systems.
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Affiliation(s)
- Sarah C Donelan
- Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, 430 Nahant Road, Nahant, MA 01908, USA
| | - Geoffrey C Trussell
- Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, 430 Nahant Road, Nahant, MA 01908, USA
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74
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St-Cyr S, McGowan PO. Adaptation or pathology? The role of prenatal stressor type and intensity in the developmental programing of adult phenotype. Neurotoxicol Teratol 2018; 66:113-124. [DOI: 10.1016/j.ntt.2017.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/25/2017] [Accepted: 12/04/2017] [Indexed: 01/06/2023]
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75
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Morales J, Lucas A, Velando A. Maternal programming of offspring antipredator behavior in a seabird. Behav Ecol 2018. [DOI: 10.1093/beheco/arx197] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Judith Morales
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales-CSIC, José Gutiérrez Abascal 2, Madrid, Spain
| | - Alberto Lucas
- Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Campus As Lagoas – Marcosende, Vigo, Spain
- Instituto Multidisciplinar para el Estudio del Medio Ramón Margalef Carretera San Vicente del Raspeig s/n, Universitat d’Alacant. Alacant, Spain
| | - Alberto Velando
- Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Campus As Lagoas – Marcosende, Vigo, Spain
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76
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Srinivasan M, Swannack TM, Grant WE, Rajan J, Würsig B. To feed or not to feed? Bioenergetic impacts of fear-driven behaviors in lactating dolphins. Ecol Evol 2017; 8:1384-1398. [PMID: 29375805 PMCID: PMC5773337 DOI: 10.1002/ece3.3732] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/26/2017] [Accepted: 11/22/2017] [Indexed: 11/25/2022] Open
Abstract
In mammals, lactation can be the most energetically expensive part of the reproductive cycle. Thus, when energy needs are compromised due to predation risk, environmental disturbance, or resource scarcity, future reproductive success can be impacted. In marine and terrestrial environments, foraging behavior is inextricably linked to predation risk. But quantification of foraging energetics for lactating animals under predation risk is less understood. In this study, we used a spatially explicit individual‐based model to study how changes in physiology (lactating or not) and the environment (predation risk) affect optimal behavior in dolphins. Specifically, we predicted that an adult dolphin without calf would incur lower relative energetic costs compared to a lactating dolphin with calf regardless of predation risk severity, antipredator behavior, or prey quality consumed. Under this state‐dependent analysis of risk approach, we found predation risk to be a stronger driver in affecting total energetic costs (foraging plus locomotor costs) than food quality for both dolphin types. Further, contrary to our hypothesis, after accounting for raised energy demands, a lactating dolphin with calf does not necessarily have higher relative‐to‐baseline costs than a dolphin without calf. Our results indicate that both a lactating (with calf) and non‐lactating dolphin incur lowered energetic costs under a risk‐averse behavioral scheme, but consequently suffer from lost foraging calories. A lactating dolphin with calf could be particularly worse off in lost foraging calories under elevated predation risk, heightened vigilance, and increased hiding time relative to an adult dolphin without calf. Further, hiding time in refuge could be more consequential than detection distance for both dolphin types in estimated costs and losses incurred. In conclusion, our study found that reproductive status is an important consideration in analyzing risk effects in mammals, especially in animals with lengthy lactation periods and those exposed to both biological and nonbiological stressors.
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Affiliation(s)
- Mridula Srinivasan
- Office of Science and Technology National Marine Fisheries Service (NMFS) Silver Spring MD USA
| | - Todd M Swannack
- U.S. Army Engineer Research and Development Center Vicksburg MS USA.,Department of Biology Texas State University San Marcos TX USA
| | - William E Grant
- Ecological Systems Laboratory, Department of Wildlife and Fisheries Sciences Texas A & M University College Station TX USA
| | - Jolly Rajan
- EcoLogik Consulting Group LLC Washington DC USA
| | - Bernd Würsig
- Department of Wildlife and Fisheries Sciences and Marine Biology Texas A & M University Galveston TX USA
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77
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Donelan SC, Trussell GC. Synergistic effects of parental and embryonic exposure to predation risk on prey offspring size at emergence. Ecology 2017; 99:68-78. [PMID: 29083481 DOI: 10.1002/ecy.2067] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/20/2017] [Accepted: 10/16/2017] [Indexed: 12/22/2022]
Abstract
Cues signaling predation risk can strongly influence prey phenotypes both within and between generations. Parental and embryonic effects have been shown to operate independently in response to predation risk, but how they interact to shape offspring life history traits remains largely unknown. Here, we conducted experiments to examine the synergistic impacts of parental and embryonic experiences with predation risk on offspring size at emergence in the snail, Nucella lapillus, which is an ecologically important intermediate consumer on rocky intertidal shores. We found that when embryos were exposed to predation risk, the offspring of risk-experienced parents emerged larger than those of parents that had no risk experience. This response was not the result of increased development time, greater resource availability, or fewer emerging offspring, but may have occurred because both parental and embryonic experiences with risk increased growth efficiency, perhaps by reducing embryonic respiration rates under risk. Our results highlight the potential for organisms to be influenced by a complex history of environmental signals with important consequences for individual fitness and predator-prey interactions.
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Affiliation(s)
- Sarah C Donelan
- Marine Science Center and the Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts, 01908, USA
| | - Geoffrey C Trussell
- Marine Science Center and the Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts, 01908, USA
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78
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Bonier F, Martin PR. How can we estimate natural selection on endocrine traits? Lessons from evolutionary biology. Proc Biol Sci 2017; 283:rspb.2016.1887. [PMID: 27881753 DOI: 10.1098/rspb.2016.1887] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/17/2016] [Indexed: 12/25/2022] Open
Abstract
An evolutionary perspective can enrich almost any endeavour in biology, providing a deeper understanding of the variation we see in nature. To this end, evolutionary endocrinologists seek to describe the fitness consequences of variation in endocrine traits. Much of the recent work in our field, however, follows a flawed approach to the study of how selection shapes endocrine traits. Briefly, this approach relies on among-individual correlations between endocrine phenotypes (often circulating hormone levels) and fitness metrics to estimate selection on those endocrine traits. Adaptive plasticity in both endocrine and fitness-related traits can drive these correlations, generating patterns that do not accurately reflect natural selection. We illustrate why this approach to studying selection on endocrine traits is problematic, referring to work from evolutionary biologists who, decades ago, described this problem as it relates to a variety of other plastic traits. We extend these arguments to evolutionary endocrinology, where the likelihood that this flaw generates bias in estimates of selection is unusually high due to the exceptional responsiveness of hormones to environmental conditions, and their function to induce adaptive life-history responses to environmental variation. We end with a review of productive approaches for investigating the fitness consequences of variation in endocrine traits that we expect will generate exciting advances in our understanding of endocrine system evolution.
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Affiliation(s)
- Frances Bonier
- Biology Department, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Paul R Martin
- Biology Department, Queen's University, Kingston, Ontario, Canada K7L 3N6
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79
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Lafferty DJR, Kumar AV, Whitcher S, Hackländer K, Mills LS. Within-sample variation in snowshoe hare faecal glucocorticoid metabolite measurements. CONSERVATION PHYSIOLOGY 2017; 5:cox068. [PMID: 29250332 PMCID: PMC5721371 DOI: 10.1093/conphys/cox068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/31/2017] [Accepted: 11/17/2017] [Indexed: 05/30/2023]
Abstract
Faecal glucocorticoid metabolite (FGM) concentrations are used increasingly as a non-invasive measure to index physiological stress experienced by diverse taxa. However, FGM may not be evenly distributed throughout a faecal mass or faecal pellet group. Moreover, within-sample variation in FGM measurements associated with different sampling and/or processing techniques is rarely reported despite potentially having important implications for inferring stress levels in free-ranging wildlife. Using a captive collection of snowshoe hares (Lepus americanus), we (i) assessed repeatability of FGM measurements (i.e. precision) from two processing techniques (measurements derived from dividing whole pellet groups into equal proportions prior to processing [G1], measurements from subsamples derived from thoroughly homogenized whole pellet groups [G2]) and (ii) conducted a power analysis to estimate sample-size requirements for detecting statistically significant differences in FGM concentrations at a population level. Our results indicate that the mean percent coefficient of variation (%CV) for within-sample FGM variation was slightly higher for G1 (%CV = 35, range 13.45-65.37) than for G2 (%CV = 23, range 7.26-47.94), though not statistically significant (two sample t-test, n = 8, t = 1.57, P = 0.16). Thus, FGM is relatively evenly distributed within snowshoe hare faecal pellet groups. However, subsampling from homogenized whole pellet groups may be more appropriate when the sampling time frame is less controlled (e.g. multiple defecation events) because a subsample derived from a homogenized whole pellet group might be more representative of the animal's 'average' physiological state compared to FGM concentrations derived from a few haphazardly selected faecal pellets. Power analysis results demonstrated the importance of a priori consideration of sample sizes. Relatively small effect sizes (e.g. <20%) may require sampling that is logistically and/or cost prohibitive. Yet for many situations of ecological or conservation interest, treatment effects may be substantial (>25%) and thus moderate sample sizes may be sufficient for testing research hypotheses regarding changes FGM concentrations.
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Affiliation(s)
- Diana J R Lafferty
- Fisheries, Wildlife, and Conservation Biology Program, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
- Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA
- Department of Biology, Northern Michigan University, Marquette, MI 49855, USA
| | - Alexander V Kumar
- Fisheries, Wildlife, and Conservation Biology Program, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
- Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA
| | - Sarah Whitcher
- Fisheries, Wildlife, and Conservation Biology Program, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - Klaus Hackländer
- Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna (BOKU), Gregor-Mendel-Str. 33, 1180 Vienna, Austria
| | - L Scott Mills
- Fisheries, Wildlife, and Conservation Biology Program, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
- Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA
- Office of Research and Creative Scholarship, University of Montana, Missoula, MT 59812, USA
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80
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MacLeod KJ, Krebs CJ, Boonstra R, Sheriff MJ. Fear and lethality in snowshoe hares: the deadly effects of non-consumptive predation risk. OIKOS 2017. [DOI: 10.1111/oik.04890] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kirsty J. MacLeod
- Dept of Ecosystem Science and Management; Pennsylvania State Univ., Forest Resources Building, University Park; PA 16802 USA
- Dept of Biology; Pennsylvania State Univ., University Park; PA USA
| | | | - Rudy Boonstra
- Centre of the Neurobiology of Stress, Dept of Biological Sciences, Univ. of Toronto Scarborough; Toronto ON Canada
| | - Michael J. Sheriff
- Dept of Ecosystem Science and Management; Pennsylvania State Univ., Forest Resources Building, University Park; PA 16802 USA
- Huck Inst. of the Life Sciences, Pennsylvania State Univ., University Park; PA USA
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81
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Krause JS, Pérez JH, Meddle SL, Wingfield JC. Effects of short-term fasting on stress physiology, body condition, and locomotor activity in wintering male white-crowned sparrows. Physiol Behav 2017; 177:282-290. [DOI: 10.1016/j.physbeh.2017.04.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 02/03/2023]
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82
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Krebs CJ, Boonstra R, Boutin S. Using experimentation to understand the 10‐year snowshoe hare cycle in the boreal forest of North America. J Anim Ecol 2017. [DOI: 10.1111/1365-2656.12720] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Charles J. Krebs
- Department of ZoologyUniversity of British Columbia Vancouver BC Canada
| | - Rudy Boonstra
- Department of Biological SciencesUniversity of Toronto Scarborough Toronto ON Canada
| | - Stan Boutin
- Department of Biological SciencesUniversity of Alberta Edmonton AB Canada
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83
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Barraquand F, Louca S, Abbott KC, Cobbold CA, Cordoleani F, DeAngelis DL, Elderd BD, Fox JW, Greenwood P, Hilker FM, Murray DL, Stieha CR, Taylor RA, Vitense K, Wolkowicz GS, Tyson RC. Moving forward in circles: challenges and opportunities in modelling population cycles. Ecol Lett 2017. [DOI: 10.1111/ele.12789] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Frédéric Barraquand
- Department of Arctic and Marine Biology University of Tromsø Tromsø Norway
- Integrative and Theoretical Ecology Chair, LabEx COTE University of Bordeaux Pessac France
| | - Stilianos Louca
- Institute of Applied Mathematics University of British Columbia Vancouver BC Canada
| | - Karen C. Abbott
- Department of Biology Case Western Reserve University Cleveland OH USA
| | | | - Flora Cordoleani
- Institute of Marine Science University of California Santa Cruz Santa Cruz CA USA
- Southwest Fisheries Science Center Santa Cruz CA USA
| | | | - Bret D. Elderd
- Department of Biological Sciences Lousiana State University Baton Rouge LA USA
| | - Jeremy W. Fox
- Department of Biological Sciences University of Calgary Calgary ABCanada
| | | | - Frank M. Hilker
- Institute of Environmental Systems Research, School of Mathematics/Computer Science Osnabrück University Osnabrück Germany
| | - Dennis L. Murray
- Integrative Wildlife Conservation Lab Trent University Peterborough ONCanada
| | - Christopher R. Stieha
- Department of Biology Case Western Reserve University Cleveland OH USA
- Department of Entomology Cornell University Ithaca NY USA
| | - Rachel A. Taylor
- Department of Integrative Biology University of South Florida Tampa FLUSA
| | - Kelsey Vitense
- Department of Fisheries, Wildlife, and Conservation Biology University of Minnesota Saint Paul MN USA
| | - Gail S.K. Wolkowicz
- Department of Mathematics and Statistics McMaster University Hamilton ON Canada
| | - Rebecca C. Tyson
- Department of Mathematics and Statistics University of British Columbia Okanagan Kelowna BC Canada
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84
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Davy CM, Mastromonaco GF, Riley JL, Baxter-Gilbert JH, Mayberry H, Willis CKR. Conservation implications of physiological carry-over effects in bats recovering from white-nose syndrome. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:615-624. [PMID: 27641049 DOI: 10.1111/cobi.12841] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/19/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Abstract
Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long-term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry-over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white-nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free-ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than naïve individuals. Thus, cryptic physiological carry-over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.
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Affiliation(s)
- Christina M Davy
- Natural Resources DNA Profiling and Forensics Centre, Trent University, Peterborough, ON, K9J 7B8, Canada
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
| | | | - Julia L Riley
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - James H Baxter-Gilbert
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - Heather Mayberry
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Craig K R Willis
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
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85
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Pottinger TG. Modulation of the stress response in wild fish is associated with variation in dissolved nitrate and nitrite. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 225:550-558. [PMID: 28318786 DOI: 10.1016/j.envpol.2017.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/24/2017] [Accepted: 03/09/2017] [Indexed: 06/06/2023]
Abstract
Disruption of non-reproductive endocrine systems in wildlife by chemicals has received little attention but represents a potentially significant problem. Nitrate is a major anthropogenic contaminant in the freshwater aquatic environment and has been identified as a potential disrupter of endocrine function in aquatic animals. This study was conducted to investigate the relationship between the function of the neuroendocrine stress axis in fish and inorganic N loading along reaches of rivers receiving cumulative point source and diffuse chemical inputs. To accomplish this, the responsiveness of the stress axis, quantified as the rate of release of cortisol to water across the gills during exposure to a standardised stressor, was measured in three-spined sticklebacks (Gasterosteus aculeatus L.) resident at three sites on each of four rivers in north-west England. The magnitude of the stress response in fish captured at the sites furthest downstream on all rivers was more than twice that of fish captured at upstream sites. Site-specific variation in stress axis reactivity was better explained by between-site variation in concentrations of dissolved nitrate, nitrite, and ammonia than by the concentration of wastewater treatment works effluent. An increase in the magnitude of the stress response was seen among sticklebacks at sites where long-term averaged concentrations of NH3-N, NO3-N and NO2-N exceeded 0.6, 4.0 and 0.1 mg/L respectively. These data suggest that either (i) inorganic N is a better surrogate than wastewater effluent concentration for an unknown factor or factors affecting stress axis function in fish, or (ii) dissolved inorganic N directly exerts a disruptive influence on the function of the neuroendocrine stress axis in fish, supporting concerns that nitrate is an endocrine-modulating chemical.
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Affiliation(s)
- Tom G Pottinger
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK.
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86
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Ng’weno CC, Maiyo NJ, Ali AH, Kibungei AK, Goheen JR. Lions influence the decline and habitat shift of hartebeest in a semiarid savanna. J Mammal 2017. [DOI: 10.1093/jmammal/gyx040] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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87
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Tigreros N, Norris RH, Wang EH, Thaler JS. Maternally induced intraclutch cannibalism: an adaptive response to predation risk? Ecol Lett 2017; 20:487-494. [DOI: 10.1111/ele.12752] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/10/2017] [Accepted: 01/27/2017] [Indexed: 11/30/2022]
Affiliation(s)
| | - Rachel H. Norris
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY12854 USA
| | - Eugenia H. Wang
- Department of Entomology Cornell University Ithaca NY12854 USA
| | - Jennifer S. Thaler
- Department of Entomology Cornell University Ithaca NY12854 USA
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY12854 USA
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88
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Okhovat M, Maguire SM, Phelps SM. Methylation of avpr1a in the cortex of wild prairie voles: effects of CpG position and polymorphism. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160646. [PMID: 28280564 PMCID: PMC5319330 DOI: 10.1098/rsos.160646] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/19/2016] [Indexed: 06/06/2023]
Abstract
DNA methylation can cause stable changes in neuronal gene expression, but we know little about its role in individual differences in the wild. In this study, we focus on the vasopressin 1a receptor (avpr1a), a gene extensively implicated in vertebrate social behaviour, and explore natural variation in DNA methylation, genetic polymorphism and neuronal gene expression among 30 wild prairie voles (Microtus ochrogaster). Examination of CpG density across 8 kb of the locus revealed two distinct CpG islands overlapping promoter and first exon, characterized by few CpG polymorphisms. We used a targeted bisulfite sequencing approach to measure DNA methylation across approximately 3 kb of avpr1a in the retrosplenial cortex, a brain region implicated in male space use and sexual fidelity. We find dramatic variation in methylation across the avrp1a locus, with pronounced diversity near the exon-intron boundary and in a genetically variable putative enhancer within the intron. Among our wild voles, differences in cortical avpr1a expression correlate with DNA methylation in this putative enhancer, but not with the methylation status of the promoter. We also find an unusually high number of polymorphic CpG sites (polyCpGs) in this focal enhancer. One polyCpG within this enhancer (polyCpG 2170) may drive variation in expression either by disrupting transcription factor binding motifs or by changing local DNA methylation and chromatin silencing. Our results contradict some assumptions made within behavioural epigenetics, but are remarkably concordant with genome-wide studies of gene regulation.
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Affiliation(s)
- M. Okhovat
- Author for correspondence: M. Okhovat e-mail:
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89
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Okhovat M, Maguire SM, Phelps SM. Methylation of avpr1a in the cortex of wild prairie voles: effects of CpG position and polymorphism. ROYAL SOCIETY OPEN SCIENCE 2017. [PMID: 28280564 DOI: 10.5061/dryad.f8d4r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
DNA methylation can cause stable changes in neuronal gene expression, but we know little about its role in individual differences in the wild. In this study, we focus on the vasopressin 1a receptor (avpr1a), a gene extensively implicated in vertebrate social behaviour, and explore natural variation in DNA methylation, genetic polymorphism and neuronal gene expression among 30 wild prairie voles (Microtus ochrogaster). Examination of CpG density across 8 kb of the locus revealed two distinct CpG islands overlapping promoter and first exon, characterized by few CpG polymorphisms. We used a targeted bisulfite sequencing approach to measure DNA methylation across approximately 3 kb of avpr1a in the retrosplenial cortex, a brain region implicated in male space use and sexual fidelity. We find dramatic variation in methylation across the avrp1a locus, with pronounced diversity near the exon-intron boundary and in a genetically variable putative enhancer within the intron. Among our wild voles, differences in cortical avpr1a expression correlate with DNA methylation in this putative enhancer, but not with the methylation status of the promoter. We also find an unusually high number of polymorphic CpG sites (polyCpGs) in this focal enhancer. One polyCpG within this enhancer (polyCpG 2170) may drive variation in expression either by disrupting transcription factor binding motifs or by changing local DNA methylation and chromatin silencing. Our results contradict some assumptions made within behavioural epigenetics, but are remarkably concordant with genome-wide studies of gene regulation.
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Affiliation(s)
- M Okhovat
- Department of Integrative Biology , University of Texas at Austin , Austin, TX , USA
| | - S M Maguire
- Department of Integrative Biology , University of Texas at Austin , Austin, TX , USA
| | - S M Phelps
- Department of Integrative Biology , University of Texas at Austin , Austin, TX , USA
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90
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Moks K, Tilgar V, Thomson RL, Calhim S, Järvistö PE, Schuett W, Velmala W, Laaksonen T. Predator encounters have spatially extensive impacts on parental behaviour in a breeding bird community. Proc Biol Sci 2016; 283:20160020. [PMID: 27030411 DOI: 10.1098/rspb.2016.0020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/29/2016] [Indexed: 11/12/2022] Open
Abstract
Predation risk has negative indirect effects on prey fitness, partly mediated through changes in behaviour. Evidence that individuals gather social information from other members of the population suggests that events in a community may impact the behaviour of distant individuals. However, spatially wide-ranging impacts on individual behaviour caused by a predator encounter elsewhere in a community have not been documented before. We investigated the effect of a predator encounter (hawk model presented at a focal nest) on the parental behaviour of pied flycatchers (Ficedula hypoleuca), both at the focal nest and at nearby nests different distances from the predator encounter. We show that nest visitation of both focal pairs and nearby pairs were affected, up to 3 h and 1 h, respectively. Parents also appeared to compensate initial disrupted feeding by later increasing nest visitation rates. This is the first evidence showing that the behaviour of nearby pairs was affected away from an immediate source of risk. Our results indicate that the impacts of short-term predator encounters may immediately extend spatially to the broader community, affecting the behaviour of distant individuals. Information about predators is probably quickly spread by cues such as intra- and heterospecific alarm calls, in communities of different taxa.
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Affiliation(s)
- Kadri Moks
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Tartu 51014, Estonia
| | - Vallo Tilgar
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Tartu 51014, Estonia
| | - Robert L Thomson
- Section of Ecology, Department of Biology, University of Turku, Turku 20014, Finland Percy FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa
| | - Sara Calhim
- Section of Ecology, Department of Biology, University of Turku, Turku 20014, Finland Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, Jyväskylä 40014, Finland
| | - Pauliina E Järvistö
- Section of Ecology, Department of Biology, University of Turku, Turku 20014, Finland
| | - Wiebke Schuett
- Zoological Institute, Biocenter Grindel, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg 20146, Germany
| | - William Velmala
- Section of Ecology, Department of Biology, University of Turku, Turku 20014, Finland
| | - Toni Laaksonen
- Section of Ecology, Department of Biology, University of Turku, Turku 20014, Finland
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91
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Bateson P. Robustness and plasticity in development. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2016; 8. [PMID: 27906506 DOI: 10.1002/wcs.1386] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 12/28/2015] [Accepted: 01/28/2016] [Indexed: 11/10/2022]
Abstract
Like the game of chess, the overall development of human behavior is highly regulated, and also many finer points of any particular individual life depend on early moves. The robust mechanisms that make species different from each other also impact processes that make individuals distinct from one another. Children both influence their environment and are influenced by it. As the development of any particular skill depends upon the contribution of particular environmental inputs at particular times, environmental variability can dramatically change the process. Development is seldom a linear process: while large environmental changes sometimes have little effect on developmental outcomes, small changes can have enormous (if not always immediate) effects. If we are to unravel these complex interdependencies, we must study the interplay among developmental factors that generates change. WIREs Cogn Sci 2017, 8:e1386. doi: 10.1002/wcs.1386 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Patrick Bateson
- Department of Zoology, Downing Street, University of Cambridge, Cambridge, UK
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92
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Chaby LE. Why are there lasting effects from exposure to stress during development? An analysis of current models of early stress. Physiol Behav 2016; 164:164-81. [DOI: 10.1016/j.physbeh.2016.05.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 04/29/2016] [Accepted: 05/17/2016] [Indexed: 01/19/2023]
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93
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Tilgar V, Mägi M, Lind M, Lodjak J, Moks K, Mänd R. Acute embryonic exposure to corticosterone alters physiology, behaviour and growth in nestlings of a wild passerine. Horm Behav 2016; 84:111-20. [PMID: 27374762 DOI: 10.1016/j.yhbeh.2016.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/08/2016] [Accepted: 06/26/2016] [Indexed: 11/27/2022]
Abstract
Maternally-derived glucocorticoids can modify the normal development of young animals. To date, little is known about maternal effects that are mediated by acute embryonic exposure to glucocorticoids. In birds, elevated maternal transmission of corticosterone (CORT) to egg albumen is mainly dependent on acute stress. In this study, we increased CORT levels in the egg albumen of a wild passerine, the great tit (Parus major), breeding in favourable deciduous and less suitable coniferous habitat. Subsequently we measured the somatic growth, baseline and acute glucocorticoid responses, immunity and behaviour of prenatally manipulated offspring with respect to control siblings. We found that prenatally CORT-exposed nestlings had lower baseline CORT levels, a more rapid decline in CORT during recovery from a standardized stressor, and a reduced heterophil/lymphocyte ratio compared with controls. Although stress-induced total CORT levels remained unchanged, free CORT levels were significantly lower and the levels of corticosteroid binding globulins (CBG) significantly higher in experimental offspring. Prenatally CORT-exposed offspring begged longer after hatching than controls. Stress-induced behavioural activity of fledglings did not differ between treatments, while its association with baseline CORT levels was significant in the control group only. The body mass and tarsus length of fledglings was positively affected by manipulation in unfavourable coniferous habitat only. We conclude that maternal effects related to elevated levels of albumen CORT modify diverse aspects of offspring phenotype and potentially increase offspring performance in resource poor environments. Moreover, our results indicate that maternal glucocorticoids may suppress the effect of hormones on behavioural responses.
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Affiliation(s)
- Vallo Tilgar
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Marko Mägi
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Marianne Lind
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Jaanis Lodjak
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Kadri Moks
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Raivo Mänd
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
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94
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Schell CJ, Young JK, Lonsdorf EV, Mateo JM, Santymire RM. Olfactory attractants and parity affect prenatal androgens and territoriality of coyote breeding pairs. Physiol Behav 2016; 165:43-54. [PMID: 27378509 DOI: 10.1016/j.physbeh.2016.06.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 01/28/2023]
Abstract
Hormones are fundamental mediators of personality traits intimately linked with reproductive success. Hence, alterations to endocrine factors may dramatically affect individual behavior that has subsequent fitness consequences. Yet it is unclear how hormonal or behavioral traits change with environmental stressors or over multiple reproductive opportunities, particularly for biparental fauna. To simulate an environmental stressor, we exposed captive coyote (Canis latrans) pairs to novel coyote odor attractants (i.e. commercial scent lures) mid-gestation to influence territorial behaviors, fecal glucocorticoid (FGMs) and fecal androgen metabolites (FAMs). In addition, we observed coyote pairs as first-time and experienced breeders to assess the influence of parity on our measures. Treatment pairs received the odors four times over a 20-day period, while control pairs received water. Odor-treated pairs scent-marked (e.g. urinated, ground scratched) and investigated odors more frequently than control pairs, and had higher FAMs when odors were provided. Pairs had higher FAMs as first-time versus experienced breeders, indicating that parity also affected androgen production during gestation. Moreover, repeatability in scent-marking behaviors corresponded with FGMs and FAMs, implying that coyote territoriality during gestation is underpinned by individually-specific hormone profiles. Our results suggest coyote androgens during gestation are sensitive to conspecific olfactory stimuli and prior breeding experience. Consequently, fluctuations in social or other environmental stimuli as well as increasing parity may acutely affect coyote traits essential to reproductive success.
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Affiliation(s)
- Christopher J Schell
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States.
| | - Julie K Young
- USDA-WS-NWRC, Predator Research Facility, Department of Wildland Resources, Utah State University, USU - BNR 163, Logan, UT 84322, United States
| | - Elizabeth V Lonsdorf
- Department of Psychology, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17603, United States
| | - Jill M Mateo
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States
| | - Rachel M Santymire
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States; Department of Conservation and Science, Lincoln Park Zoo, 2001 N. Clark St., Chicago, IL 60614, United States
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95
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Bowers EK, Bowden RM, Thompson CF, Sakaluk SK. Elevated corticosterone during egg production elicits increased maternal investment and promotes nestling growth in a wild songbird. Horm Behav 2016; 83:6-13. [PMID: 27189763 PMCID: PMC4915999 DOI: 10.1016/j.yhbeh.2016.05.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 05/11/2016] [Accepted: 05/13/2016] [Indexed: 12/30/2022]
Abstract
Glucocorticoids circulating in breeding birds during egg production accumulate within eggs, and may provide a potent form of maternal effect on offspring phenotype. However, whether these steroids affect offspring development remains unclear. Here, we employed a non-invasive technique that experimentally elevated the maternal transfer of corticosterone to eggs in a wild population of house wrens. Feeding corticosterone-injected mealworms to free-living females prior to and during egg production increased the number of eggs that females produced and increased corticosterone concentrations in egg yolks. This treatment also resulted in an increase in the amount of yolk allocated to eggs. Offspring hatching from these eggs begged for food at a higher rate than control offspring and eventually attained increased prefledging body condition, a trait predictive of their probability of recruitment as breeding adults in the study population. Our results indicate that an increase in maternal glucocorticoids within the physiological range can enhance maternal investment and offspring development.
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Affiliation(s)
- E Keith Bowers
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA.
| | - Rachel M Bowden
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Charles F Thompson
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Scott K Sakaluk
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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96
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Edwards PD, Boonstra R. Coping with pregnancy after 9months in the dark: Post-hibernation buffering of high maternal stress in arctic ground squirrels. Gen Comp Endocrinol 2016; 232:1-6. [PMID: 26555380 DOI: 10.1016/j.ygcen.2015.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 10/08/2015] [Accepted: 11/06/2015] [Indexed: 11/29/2022]
Abstract
Pregnancy and lactation are key times in the life of female mammals when energetic resources must be brought to bear to produce and nurture offspring. Changes in glucocorticoid (GC) levels are central to this objective, due to their roles in modulating development and physiology and in mediating energetic tradeoffs. We examined GC changes over reproduction in a species living in a harsh seasonal environment: the arctic ground squirrel (Urocitellus parryii). Females become pregnant immediately after emerging from a ∼9month hibernation, and then must begin this pregnancy during an additional month of freezing temperatures and limited food availability. We measured plasma levels of total cortisol, corticosteroid-binding globulin (CBG), and free cortisol in unstressed females at three stages: not-visibly pregnant, visibly pregnant, and lactating. Total cortisol levels were similar in all stages, but CBG levels increased 4-fold from the not-visibly pregnant stage to visibly pregnant and lactating stage. As a result, the free cortisol fraction declined from 51% of total cortisol when females were not-visibly pregnant to only 5% when they were visibly pregnant (remaining low and stable throughout pregnancy) and 10% when they were lactating. This pattern is markedly different from that seen in other mammals, where 10% or less of GCs are free and these tend to increase during gestation. We postulate that the high free cortisol just prior to visible pregnancy is a seasonal adaptation relating either to the pronounced physiological changes the female must undergo after emerging from hibernation and immediately getting pregnant, or to the mobilization of body reserves for energy to permit pregnancy, or both. Thereafter, high CBG levels may shield the developing offspring from the negative effects of cortisol overexposure.
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Affiliation(s)
- Phoebe D Edwards
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
| | - Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
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97
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Tucker S, Hipfner JM, Trudel M. Size- and condition-dependent predation: a seabird disproportionately targets substandard individual juvenile salmon. Ecology 2016; 97:461-71. [PMID: 27145620 DOI: 10.1890/15-0564.1] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Selection of prey that are small and in poor body condition is a widespread phenomenon in terrestrial predator-prey systems and may benefit prey populations by removing substandard individuals. Similar selection is widely assumed to operate in aquatic systems. Indeed, size-selective predation is a longstanding and central tenet of aquatic food web theory. However, it is not known if aquatic predators select prey based on their condition or state, compared to their size. Surprisingly, no comparable information is available for marine systems because it is exceedingly difficult to make direct observations in this realm. Thus the role of body condition in regulating susceptibility to predation remains a black box in the marine environment. Here we have exploited an ideal model system to evaluate selective predation on pelagic marine fish: comparing characteristics (fork length, mass corrected for fork length) of fresh, whole, intact juvenile Pacific salmon delivered by a seabird to its single nestling with salmon collected concurrently in coastal trawl surveys. Three species of juvenile salmon (Oncorhynchus spp.) are consumed by provisioning Rhinoceros Auklets (Cerorhinca nionocerata); an abundant, colonial, pursuit-diving seabird. Samples were collected from multiple colonies and fisheries surveys in coastal British Columbia in two years. As predicted, Auklets preyed on small individuals in poor condition and consistently selected them at levels higher than their relative availability. This is the first study to provide direct evidence for both size- and condition-selective predation on marine fish in the wild. We anticipate that our results will be a starting point in evaluating how selective predation may structure or influence marine fish populations and bridges a fundamental incongruity between ecological theory and application; although "bigger is better" is considered a fundamental tenet of marine food webs, marine predators are often assumed to consume indiscriminately.
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98
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Harris BN, Carr JA. The role of the hypothalamus-pituitary-adrenal/interrenal axis in mediating predator-avoidance trade-offs. Gen Comp Endocrinol 2016; 230-231:110-42. [PMID: 27080550 DOI: 10.1016/j.ygcen.2016.04.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 04/07/2016] [Accepted: 04/09/2016] [Indexed: 11/20/2022]
Abstract
Maintaining energy balance and reproducing are important for fitness, yet animals have evolved mechanisms by which the hypothalamus-pituitary-adrenal/interrenal (HPA/HPI) axis can shut these activities off. While HPA/HPI axis inhibition of feeding and reproduction may have evolved as a predator defense, to date there has been no review across taxa of the causal evidence for such a relationship. Here we review the literature on this topic by addressing evidence for three predictions: that exposure to predators decreases reproduction and feeding, that exposure to predators activates the HPA/HPI axis, and that predator-induced activation of the HPA/HPI axis inhibits foraging and reproduction. Weight of evidence indicates that exposure to predator cues inhibits several aspects of foraging and reproduction. While the evidence from fish and mammals supports the hypothesis that predator cues activate the HPA/HPI axis, the existing data in other vertebrate taxa are equivocal. A causal role for the HPA axis in predator-induced suppression of feeding and reproduction has not been demonstrated to date, although many studies report correlative relationships between HPA activity and reproduction and/or feeding. Manipulation of HPA/HPI axis signaling will be required in future studies to demonstrate direct mediation of predator-induced inhibition of feeding and reproduction. Understanding the circuitry linking sensory pathways to their control of the HPA/HPI axis also is needed. Finally, the role that fear and anxiety pathways play in the response of the HPA axis to predator cues is needed to better understand the role that predators have played in shaping anxiety related behaviors in all species, including humans.
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Affiliation(s)
- Breanna N Harris
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, United States
| | - James A Carr
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, United States.
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99
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Sheriff MJ. The adaptive potential of maternal stress exposure in regulating population dynamics. J Anim Ecol 2016; 84:323-5. [PMID: 26247815 DOI: 10.1111/1365-2656.12334] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 01/06/2015] [Indexed: 11/28/2022]
Abstract
Ecologists, evolutionary biologists and biomedical researchers are investing great effort in understanding the impact maternal stress may have on offspring phenotypes. Bian et al. advance this field by providing evidence that density-induced maternal stress programs offspring phenotypes, resulting in direct consequences on their fitness and population dynamics, but doing so in a context-dependent manner. They suggest that intrinsic state alterations induced by maternal stress may be one ecological factor generating delayed density-dependent effects. This research highlights the connection between maternal stress and population dynamics, and the importance of understanding the adaptive potential of such effects in a context-dependent manner.
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Affiliation(s)
- Michael J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA 16802, USA
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100
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Bell AM, McGhee KE, Stein L. Effects of mothers' and fathers' experience with predation risk on the behavioral development of their offspring in threespined sticklebacks. Curr Opin Behav Sci 2016; 7:28-32. [PMID: 26858970 DOI: 10.1016/j.cobeha.2015.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Stressors experienced by parents can influence the behavioral development of their offspring. Here, we review recent studies in threespined sticklebacks (a species in which males are the sole providers of parental care) showing that when parents are exposed to an ecologically relevant stressor (predation risk), there are consequences for offspring. For example, female sticklebacks exposed to predation risk produce eggs with higher concentrations of cortisol, a stress hormone, and offspring with altered behavior and physiology. Male sticklebacks exposed to predation risk produce offspring that are less active, smaller, and in poorer condition. The precise mechanisms by which maternal and paternal experiences with predators affect offspring phenotypes are under investigation, and could include steroid hormones, olfactory cues and/or parental behavior. As in other species, some of the consequences of parental exposure to predation risk for offspring in sticklebacks might be adaptive, but depend on the stressor, the reliability of the parental and offspring environments and the evolutionary history of the population.
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Affiliation(s)
- Alison M Bell
- Department of Animal Biology, School of Integrative Biology, 505 S. Goodwin Ave, University of Illinois, Urbana-Champaign, IL 61801, U.S.A
| | - Katie E McGhee
- Department of Animal Biology, School of Integrative Biology, 505 S. Goodwin Ave, University of Illinois, Urbana-Champaign, IL 61801, U.S.A
| | - Laura Stein
- Department of Animal Biology, School of Integrative Biology, 505 S. Goodwin Ave, University of Illinois, Urbana-Champaign, IL 61801, U.S.A
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