1
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Batabyal A. Predator-prey systems as models for integrative research in biology: the value of a non-consumptive effects framework. J Exp Biol 2023; 226:jeb245851. [PMID: 37772622 DOI: 10.1242/jeb.245851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Predator-prey interactions are a cornerstone of many ecological and evolutionary processes that influence various levels of biological organization, from individuals to ecosystems. Predators play a crucial role in shaping ecosystems through the consumption of prey species and non-consumptive effects. Non-consumptive effects (NCEs) can induce changes in prey behavior, including altered foraging strategies, habitat selection, life history and anti-predator responses. These defensive strategies have physiological consequences for prey, affecting their growth, reproduction and immune function to name a few. Numerous experimental studies have incorporated NCEs in investigating predator-prey dynamics in the past decade. Interestingly, predator-prey systems can also be used as experimental models to answer physiology, cognition and adaptability questions. In this Commentary, I highlight research that uses NCEs in predator-prey systems to provide novel insights into cognition, adaptation, epigenetic inheritance and aging. I discuss the evolution of instinct, anxiety and other cognitive disorders, the shaping of brain connectomes, stress-induced aging and the development of behavioral coping styles. I outline how studies can integrate the investigation of NCEs with advanced behavioral, genomic and neurological tools to provide novel insights into physiological and cognitive health.
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Affiliation(s)
- Anuradha Batabyal
- Department of Physical and Natural Sciences, FLAME University, Pune 412115, India
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2
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Richards RL, Elderd BD, Duffy MA. Unhealthy herds and the predator–spreader: Understanding when predation increases disease incidence and prevalence. Ecol Evol 2023; 13:e9918. [PMID: 36969934 PMCID: PMC10037436 DOI: 10.1002/ece3.9918] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 02/14/2023] [Accepted: 03/05/2023] [Indexed: 03/26/2023] Open
Abstract
Disease ecologists now recognize the limitation behind examining host–parasite interactions in isolation: community members—especially predators—dramatically affect host–parasite dynamics. Although the initial paradigm was that predation should reduce disease in prey populations (“healthy herds hypothesis”), researchers have realized that predators sometimes increase disease in their prey. These “predator–spreaders” are now recognized as critical to disease dynamics, but empirical research on the topic remains fragmented. In a narrow sense, a “predator–spreader” would be defined as a predator that mechanically spreads parasites via feeding. However, predators affect their prey and, subsequently, disease transmission in many other ways such as altering prey population structure, behavior, and physiology. We review the existing evidence for these mechanisms and provide heuristics that incorporate features of the host, predator, parasite, and environment to understand whether or not a predator is likely to be a predator–spreader. We also provide guidance for targeted study of each mechanism and quantifying the effects of predators on parasitism in a way that yields more general insights into the factors that promote predator spreading. We aim to offer a better understanding of this important and underappreciated interaction and a path toward being able to predict how changes in predation will influence parasite dynamics.
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Affiliation(s)
- Robert L. Richards
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Bret D. Elderd
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Meghan A. Duffy
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMichiganUSA
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3
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Zhou R, Hua R, Tang Z, Hua L. Group-living decrease predation risk of individual: Evidence from behavior, hormones and reproduction of plateau pika. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1037377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Abstract
Extensive research confirms that abiotic stressors like predation risk can profoundly affect animal condition. However, there is a lack of experimental research assessing the suite of physiological responses to risk. We increased predation risk in free-living plateau pikas (Ochotona curzoniae) by simulating natural chases using a model predator (UAV: unmanned aerial vehicle) and monitored behavior, physiology, and reproduction of pikas. We found that: Predation risk affects the body weight of plateau pika under different population density stress, but the effect is not significant. Compared with the non-predation risk treatment (control), the plateau pika under high population density stress mainly responded to the risk of predation by reducing the foraging time and increasing the vigilance time, while plateau pikas under low population density pressure not only reduce foraging time and appropriately increase vigilance time, but also focus on increasing the concealing time in the burrows. The corticosterone (CORT), cortisol and thyroid (T4) level of plateau pika with low population density under the predation risk was significantly higher than those in the control, and the testosterone (T), progesterone (PROG), leptin (LEP) and testicular weight of plateau pika with low population density in the predation risk was significantly lower than those in the control. There was no difference in the litter size of female pika between predation risk treatments and control. Broadly, our result show that predation risk had significant effects on the behavior, physiology and reproduction of plateau pikas with low population density, but had no significant effect with high population density, and the response of male plateau pika to predation risk was greater than that of female. Therefore, the prevention of plateau pika should focus on the control of population density and the protection of predators, so as to avoid the failure of ecological prevention methods such as natural enemies due to the increase of population density.
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4
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Andrews CP. On the use of body mass measures in severity assessment in laboratory passerine birds. Anim Welf 2022. [DOI: 10.7120/09627286.31.1.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Criteria for assessing the severity of scientific procedures in laboratory rodents include the loss of body mass. However, guidance is limited for passerine birds and application of criteria developed for mammals risks poor welfare decisions. Here, I ask whether, and how, body mass
criteria could be incorporated into laboratory welfare assessment of passerines. Passerine birds strategically adjust their body mass to minimise combined mortality risk from starvation and predation. A systematic literature review found that strategic mass changes can be sizeable (sometimes
> 10%) even over short timescales. Many aspects of a bird's current or past environment, including husbandry and experimental procedures, may alter perceived starvation or predation risks and thus drive strategic mass change via evolved mechanisms. Therefore, body mass criteria used for
rodents may be too stringent for passerines, potentially leading to over-estimated severity. Strategic mass changes might obscure those stemming from experimental interventions yet could also offer insights into whether birds perceive an intervention or altered husbandry as a threat. Mass
criteria for severity assessment should be species- and context-specific in order to balance needs for refinement and reduction. To guide the development of appropriate criteria, a future research priority is for greater data collection and sharing based on standardised routine monitoring
of mass variation under a representative range of husbandry conditions and procedures.
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Affiliation(s)
- CP Andrews
- University of Stirling, Division of Psychology, Faculty of Natural Sciences, Stirling FK9 4LA, UK
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5
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Shultz S, Britnell JA, Harvey N. Untapped potential of physiology, behaviour and immune markers to predict range dynamics and marginality. Ecol Evol 2021; 11:16446-16461. [PMID: 34938448 PMCID: PMC8668750 DOI: 10.1002/ece3.8331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 09/09/2021] [Accepted: 10/14/2021] [Indexed: 11/16/2022] Open
Abstract
Linking environmental conditions to the modulators of individual fitness is necessary to predict long-term population dynamics, viability, and resilience. Functional physiological, behavioral, and reproductive markers can provide this mechanistic insight into how individuals perceive physiological, psychological, chemical, and physical environmental challenges through physiological and behavioral responses that are fitness proxies. We propose a Functional Marginality framework where relative changes in allostatic load, reproductive health, and behavior can be scaled up to evidence and establish causation of macroecological processes such as local extirpation, colonization, population dynamics, and range dynamics. To fully exploit functional traits, we need to move beyond single biomarker studies to develop an integrative approach that models the interactions between extrinsic challenges, physiological, and behavioral pathways and their modulators. In addition to providing mechanistic markers of range dynamics, this approach can also serve as a valuable conservation tool for evaluating individual- and population-level health, predicting responses to future environmental change and measuring the impact of interventions. We highlight specific studies that have used complementary biomarkers to link extrinsic challenges to population performance. These frameworks of integrated biomarkers have untapped potential to identify causes of decline, predict future changes, and mitigate against future biodiversity loss.
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Affiliation(s)
- Susanne Shultz
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
| | - Jake A. Britnell
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
- Chester ZooUpton‐By‐ChesterUK
| | - Nicholas Harvey
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
- Chester ZooUpton‐By‐ChesterUK
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6
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The effects of corticosterone and background colour on tadpole physiological plasticity. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 39:100872. [PMID: 34224981 DOI: 10.1016/j.cbd.2021.100872] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/20/2021] [Accepted: 06/24/2021] [Indexed: 12/25/2022]
Abstract
Corticosterone (CORT)-mediated adaptive plasticity improves animal fitness in stressful environments. Although it brings ecological benefits, the cost potentially constrains its expression and evolution. Revealing the factors affecting plasticity costs is of great ecological and evolutionary significance. Evidence indicates that both CORT and background colour can induce metabolic changes in animals, which in turn determine phenotypic plasticity. However, whether and/or how CORT and background colour jointly act on plastic responses has not been studied. Here, this question has been investigated in amphibian tadpoles (Microhyla fissipes) exposed to CORT at different background colours (white or black) using integrated morphological, histological, and transcriptomic analyses. The results showed that CORT exposure increased relative tail length, immune function, and metabolic maintenance (i.e., transcription of substrate catabolism and oxidative phosphorylation) at the expense of reduction in growth rate and skin melanin level. The black background also increased relative tail length and metabolic maintenance (i.e., transcription of oxidative phosphorylation) at the cost of reduction in growth rate, but increased skin melanin level. The expression of critical pigmentation genes indicated that black background activated a distinct and opposite pigmentation regulating route to CORT. Although there was no interactive effect of background colour and CORT on phenotypic and metabolic variations, their additive effects further impact the trade-off between somatic growth, metabolic maintenance, and pigmentation in terms of resource allocation. In conclusion, the individual and additive effects of background colour and CORT exposure on tadpole plasticity were revealed. These results likely provide new insights into the environmental adaptation of animals.
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Habitat complexity and lifetime predation risk influence mesopredator survival in a multi-predator system. Sci Rep 2020; 10:17841. [PMID: 33082386 PMCID: PMC7575546 DOI: 10.1038/s41598-020-73318-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/17/2020] [Indexed: 12/01/2022] Open
Abstract
Variability in habitat selection can lead to differences in fitness; however limited research exists on how habitat selection of mid-ranking predators can influence population-level processes in multi-predator systems. For mid-ranking, or mesopredators, differences in habitat use might have strong demographic effects because mesopredators need to simultaneously avoid apex predators and acquire prey. We studied spatially-explicit survival of cheetahs (Acinonyx jubatus) in the Mun-Ya-Wana Conservancy, South Africa, to test hypotheses related to spatial influences of predation risk, prey availability, and vegetation complexity, on mesopredator survival. For each monitored cheetah, we estimated lion encounter risk, prey density, and vegetation complexity within their home range, on short-term (seasonal) and long-term (lifetime) scales and estimated survival based on these covariates. Survival was lowest for adult cheetahs and cubs in areas with high vegetation complexity on both seasonal and lifetime scales. Additionally, cub survival was negatively related to the long-term risk of encountering a lion. We suggest that complex habitats are only beneficial to mesopredators when they are able to effectively find and hunt prey, and show that spatial drivers of survival for mesopredators can vary temporally. Collectively, our research illustrates that individual variation in mesopredator habitat use can scale-up and have population-level effects.
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8
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Fischer D, Marrotte RR, Chin EH, Coulson S, Burness G. Maternal glucocorticoid levels during incubation predict breeding success, but not reproductive investment, in a free-ranging bird. Biol Open 2020; 9:9/10/bio045898. [PMID: 33077551 PMCID: PMC7595688 DOI: 10.1242/bio.045898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The hormone corticosterone (CORT) has been hypothesized to be linked with fitness, but the directionality of the relationship is unclear. The ‘CORT-fitness hypothesis’ proposes that high levels of CORT arise from challenging environmental conditions, resulting in lower reproductive success (a negative relationship). In contrast, the CORT-adaptation hypothesis suggests that, during energetically demanding periods, CORT will mediate physiological or behavioral changes that result in increased reproductive investment and success (a positive relationship). During two breeding seasons, we experimentally manipulated circulating CORT levels in female tree swallows (Tachycineta bicolor) prior to egg laying, and measured subsequent reproductive effort, breeding success, and maternal survival. When females were recaptured during egg incubation and again during the nestling stage, the CORT levels were similar among individuals in each treatment group, and maternal treatment had no effect on indices of fitness. By considering variation among females, we found support for the CORT-adaptation hypothesis; there was a significant positive relationship between CORT levels during incubation and hatching and fledging success. During the nestling stage CORT levels were unrelated to any measure of investment or success. Within the environmental context of our study, relationships between maternal glucocorticoid levels and indices of fitness vary across reproductive stages. Summary: Levels of the stress biomarker corticosterone predict breeding success in female tree swallows. However, correlations between hormone levels and fitness differ between life-history stages.
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Affiliation(s)
- Devin Fischer
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada K9L 0G2
| | - Robby R Marrotte
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada K9L 0G2
| | - Eunice H Chin
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Smolly Coulson
- Department of Biology, Trent University, Peterborough, Ontario, Canada K9L 0G2
| | - Gary Burness
- Department of Biology, Trent University, Peterborough, Ontario, Canada K9L 0G2
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9
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Fardell LL, Pavey CR, Dickman CR. Fear and stressing in predator-prey ecology: considering the twin stressors of predators and people on mammals. PeerJ 2020; 8:e9104. [PMID: 32391213 PMCID: PMC7196326 DOI: 10.7717/peerj.9104] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 04/09/2020] [Indexed: 12/28/2022] Open
Abstract
Predators induce stress in prey and can have beneficial effects in ecosystems, but can also have negative effects on biodiversity if they are overabundant or have been introduced. The growth of human populations is, at the same time, causing degradation of natural habitats and increasing interaction rates of humans with wildlife, such that conservation management routinely considers the effects of human disturbance as tantamount to or surpassing those of predators. The need to simultaneously manage both of these threats is particularly acute in urban areas that are, increasingly, being recognized as global hotspots of wildlife activity. Pressures from altered predator-prey interactions and human activity may each initiate fear responses in prey species above those that are triggered by natural stressors in ecosystems. If fear responses are experienced by prey at elevated levels, on top of responses to multiple environmental stressors, chronic stress impacts may occur. Despite common knowledge of the negative effects of stress, however, it is rare that stress management is considered in conservation, except in intensive ex situ situations such as in captive breeding facilities or zoos. We propose that mitigation of stress impacts on wildlife is crucial for preserving biodiversity, especially as the value of habitats within urban areas increases. As such, we highlight the need for future studies to consider fear and stress in predator-prey ecology to preserve both biodiversity and ecosystem functioning, especially in areas where human disturbance occurs. We suggest, in particular, that non-invasive in situ investigations of endocrinology and ethology be partnered in conservation planning with surveys of habitat resources to incorporate and reduce the effects of fear and stress on wildlife.
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Affiliation(s)
- Loren L. Fardell
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
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10
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Effects of predation risk on egg steroid profiles across multiple populations of threespine stickleback. Sci Rep 2020; 10:5239. [PMID: 32251316 PMCID: PMC7090078 DOI: 10.1038/s41598-020-61412-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/24/2020] [Indexed: 11/16/2022] Open
Abstract
Predation often has consistent effects on prey behavior and morphology, but whether the physiological mechanisms underlying these effects show similarly consistent patterns across different populations remains an open question. In vertebrates, predation risk activates the hypothalamic-pituitary-adrenal (HPA) axis, and there is growing evidence that activation of the maternal HPA axis can have intergenerational consequences via, for example, maternally-derived steroids in eggs. Here, we investigated how predation risk affects a suite of maternally-derived steroids in threespine stickleback eggs across nine Alaskan lakes that vary in whether predatory trout are absent, native, or have been stocked within the last 25 years. Using liquid chromatography coupled with mass spectroscopy (LC-MS/MS), we detected 20 steroids within unfertilized eggs. Factor analysis suggests that steroids covary within and across steroid classes (i.e. glucocorticoids, progestogens, sex steroids), emphasizing the modularity and interconnectedness of the endocrine response. Surprisingly, egg steroid profiles were not significantly associated with predator regime, although they were more variable when predators were absent compared to when predators were present, with either native or stocked trout. Despite being the most abundant steroid, cortisol was not consistently associated with predation regime. Thus, while predators can affect steroids in adults, including mothers, the link between maternal stress and embryonic development is more complex than a simple one-to-one relationship between the population-level predation risk experienced by mothers and the steroids mothers transfer to their eggs.
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11
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Stewart ND, Mastromonaco GF, Burness G. No island-effect on glucocorticoid levels for a rodent from a near-shore archipelago. PeerJ 2020; 8:e8590. [PMID: 32110493 PMCID: PMC7034373 DOI: 10.7717/peerj.8590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 01/17/2020] [Indexed: 11/20/2022] Open
Abstract
Island rodents are often larger and live at higher population densities than their mainland counterparts, characteristics that have been referred to as "island syndrome". Island syndrome has been well studied, but few studies have tested for island-mainland differences in stress physiology. We evaluated island syndrome within the context of stress physiology of white-footed mice (Peromyscus leucopus) captured from 11 islands and five mainland sites in Thousand Islands National Park, Ontario, Canada. Stress physiology was evaluated by quantifying corticosterone (a stress biomarker), the primary glucocorticoid in mice, from hair and its related metabolites from fecal samples. White-footed mice captured in this near-shore archipelago did not display characteristics of island syndrome, nor differences in levels of hair corticosterone or fecal corticosterone metabolites compared with mainland mice. We suggest that island white-footed mice experience similar degrees of stress in the Thousand Islands compared with the mainland. Although we did not find evidence of island syndrome or differences in glucocorticoid levels, we identified relationships between internal (sex, body mass) and external (season) factors and our hormonal indices of stress in white-footed mice.
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Affiliation(s)
- Nathan D Stewart
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada
| | | | - Gary Burness
- Department of Biology, Trent University, Peterborough, Ontario, Canada
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12
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Injaian AS, Francis CD, Ouyang JQ, Dominoni DM, Donald JW, Fuxjager MJ, Goymann W, Hau M, Husak JF, Johnson MA, Kircher BK, Knapp R, Martin LB, Miller ET, Schoenle LA, Williams TD, Vitousek MN. Baseline and stress-induced corticosterone levels across birds and reptiles do not reflect urbanization levels. CONSERVATION PHYSIOLOGY 2020; 8:coz110. [PMID: 31993201 PMCID: PMC6978728 DOI: 10.1093/conphys/coz110] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 09/10/2019] [Accepted: 12/03/2019] [Indexed: 05/21/2023]
Abstract
Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, we can control for factors that may influence context, such as life history stage, environmental conditions and urban adaptability of a species. Here, we take a phylogenetically informed approach and use data from HormoneBase to test if baseline and stress-induced corticosterone are valid indicators of exposure to human footprint index, human population density, anthropogenic noise and artificial light at night in birds and reptiles. Our results show a negative relationship between anthropogenic noise and baseline corticosterone for birds characterized as urban avoiders. While our results potentially indicate that urban avoiders are more sensitive to noise than other species, overall our study suggests that the relationship between human-induced environmental change and corticosterone varies across species and contexts; we found no general relationship between human impacts and baseline and stress-induced corticosterone in birds, nor baseline corticosterone in reptiles. Therefore, it should not be assumed that high or low levels of exposure to human-induced environmental change are associated with high or low corticosterone levels, respectively, or that closely related species, or even individuals, will respond similarly. Moving forward, measuring alternative physiological traits alongside reproductive success, health and survival may provide context to better understand the potential negative effects of human-induced environmental change.
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Affiliation(s)
- Allison S Injaian
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca NY 14853, USA
- Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Ithaca NY 14850, USA
| | - Clinton D Francis
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Jenny Q Ouyang
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Davide M Dominoni
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, Netherlands
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Jeremy W Donald
- Coates Library, Trinity University, San Antonio, TX 78212, USA
| | - Matthew J Fuxjager
- Department of Ecology and Evolutionary Biology, Brown University, Providence RI 02912, USA
| | | | - Michaela Hau
- Max Planck Institute for Ornithology, Seewiesen 82319, Germany
- University of Konstanz, 78457 Konstanz, Germany
| | - Jerry F Husak
- Department of Biology, University of St. Thomas, St. Paul, MN 55105, USA
| | - Michele A Johnson
- Department of Biology, Trinity University, San Antonio, TX 78212, USA
| | - Bonnie K Kircher
- Department of Biology, University of Florida, Gainesville, FL 32608, USA
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Lynn B Martin
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | | | - Laura A Schoenle
- Office of Undergraduate Biology, Cornell University, Ithaca NY 14853, USA
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca NY 14853, USA
- Cornell Lab of Ornithology, Ithaca NY 14850, USA
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13
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Hallinger KK, Vitousek MN, Winkler DW. Differences in perceived predation risk associated with variation in relative size of extra-pair and within-pair offspring. J Evol Biol 2019; 33:282-296. [PMID: 31677203 DOI: 10.1111/jeb.13564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 12/01/2022]
Abstract
Extra-pair paternity (EPP) is a widespread phenomenon in birds. Researchers have long hypothesized that EPP must confer a fitness advantage to extra-pair offspring (EPO), but empirical support for this hypothesis is definitively mixed. This could be because genetic benefits of EPP only exist in a subset of environmental contexts to which a population is exposed. From 2013 to 2015, we manipulated perceived predator density in a population of tree swallows (Tachycineta bicolor) breeding in New York to see whether fitness outcomes of extra-pair and within-pair offspring (WPO) varied with predation risk. In nests that had been exposed to predators, EPO were larger, longer-winged and heavier than WPO. In nonpredator nests, WPO tended to be larger, longer-winged and heavier than EPO, though the effect was nonsignificant. We found no differences in age, morphology or stress physiology between extra-pair and within-pair sires from the same nest, suggesting that additive genetic benefits cannot fully explain the differences in nestling size that we observed. The lack of an effect of predator exposure on survival or glucocorticoid stress physiology of EPO and WPO further suggests that observed size differences do not reflect more general variation in intrinsic genetic quality. Instead, we suggest that size differences may have arisen through differential investment into EPO and WPO by females, perhaps because EPO and WPO represent different reproductive strategies, with each type of nestling conferring a fitness advantage in specific ecological contexts.
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Affiliation(s)
- Kelly K Hallinger
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.,Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Ithaca, NY, USA.,Cornell Lab of Ornithology, Ithaca, NY, USA
| | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.,Cornell Lab of Ornithology, Ithaca, NY, USA
| | - David W Winkler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.,Cornell Lab of Ornithology, Ithaca, NY, USA.,Cornell University Museum of Vertebrates, Ithaca, NY, USA
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14
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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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15
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Boudreau MR, Seguin JL, Boonstra R, Palme R, Boutin S, Krebs CJ, Murray DL. Experimental increase in predation risk causes a cascading stress response in free-ranging snowshoe hares. Oecologia 2019; 191:311-323. [PMID: 31535254 DOI: 10.1007/s00442-019-04500-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 09/04/2019] [Indexed: 11/26/2022]
Abstract
Extensive research confirms that environmental stressors like predation risk can profoundly affect animal condition and physiology. However, there is a lack of experimental research assessing the suite of physiological responses to risk that may arise under realistic field conditions, leaving a fragmented picture of risk-related physiological change and potential downstream consequences on individuals. We increased predation risk in free-ranging snowshoe hares (Lepus americanus) during two consecutive summers by simulating natural chases using a model predator and monitored hares intensively via radio-telemetry and physiological assays, including measures designed to assess changes in stress physiology and overall condition. Compared to controls, risk-augmented hares had 25.8% higher free plasma cortisol, 15.9% lower cortisol-binding capacity, a greater neutrophil:lymphocyte skew, and a 10.4% increase in glucose. Despite these changes, intra-annual changes in two distinct condition indices, were unaffected by risk exposure. We infer risk-augmented hares compensated for changes in their stress physiology through either compensatory foraging and/or metabolic changes, which allowed them to have comparable condition to controls. Although differences between controls and risk-augmented hares were consistent each year, both groups had heightened stress measures during the second summer, likely reflecting an increase in natural stressors (i.e., predators) in the environment. We show that increased predation risk in free-ranging animals can profoundly alter stress physiology and that compensatory responses may contribute to limiting effects of such changes on condition. Ultimately, our results also highlight the importance of biologically relevant experimental risk manipulations in the wild as a means of assessing physiological responses to natural stressors.
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Affiliation(s)
- Melanie R Boudreau
- Environmental and Life Sciences, Trent University, Peterborough, ON, K9J 0G2, Canada.
| | - Jacob L Seguin
- Environmental and Life Sciences, Trent University, Peterborough, ON, K9J 0G2, Canada
| | - Rudy Boonstra
- Center for Neurobiology of Stress, University of Toronto Scarborough, Toronto, ON, M1C 1A4, Canada
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Stan Boutin
- Faculty of Science, 1-001 CCIS, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Dennis L Murray
- Environmental and Life Sciences, Trent University, Peterborough, ON, K9J 0G2, Canada
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16
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Bain GC, Johnson CN, Jones ME. Chronic stress in superb fairy‐wrens occupying remnant woodlands: Are noisy miners to blame? AUSTRAL ECOL 2019. [DOI: 10.1111/aec.12785] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Glen C. Bain
- School of Natural Sciences University of Tasmania Hobart Tasmania 7001 Australia
| | - Chris N. Johnson
- School of Natural Sciences University of Tasmania Hobart Tasmania 7001 Australia
| | - Menna E. Jones
- School of Natural Sciences University of Tasmania Hobart Tasmania 7001 Australia
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17
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Bhattacharya S, Fontaine A, MacCallum PE, Drover J, Blundell J. Stress Across Generations: DNA Methylation as a Potential Mechanism Underlying Intergenerational Effects of Stress in Both Post-traumatic Stress Disorder and Pre-clinical Predator Stress Rodent Models. Front Behav Neurosci 2019; 13:113. [PMID: 31191267 PMCID: PMC6547031 DOI: 10.3389/fnbeh.2019.00113] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 05/07/2019] [Indexed: 12/12/2022] Open
Abstract
Although most humans will experience some type of traumatic event in their lifetime only a small set of individuals will go on to develop post-traumatic stress disorder (PTSD). Differences in sex, age, trauma type, and comorbidity, along with many other elements, contribute to the heterogenous manifestation of this disorder. Nonetheless, aberrant hypothalamus-pituitary-adrenal (HPA) axis activity, especially in terms of cortisol and glucocorticoid receptor (GR) alterations, has been postulated as a tenable factor in the etiology and pathophysiology of PTSD. Moreover, emerging data suggests that the harmful effects of traumatic stress to the HPA axis in PTSD can also propagate into future generations, making offspring more prone to psychopathologies. Predator stress models provide an ethical and ethologically relevant way to investigate tentative mechanisms that are thought to underlie this phenomenon. In this review article, we discuss findings from human and laboratory predator stress studies that suggest changes to DNA methylation germane to GRs may underlie the generational effects of trauma transmission. Understanding mechanisms that promote stress-induced psychopathology will represent a major advance in the field and may lead to novel treatments for such devastating, and often treatment-resistant trauma and stress-disorders.
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Affiliation(s)
- Sriya Bhattacharya
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Audrey Fontaine
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada.,Institut des Systèmes Intelligents et de Robotique (ISIR), Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Phillip E MacCallum
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada
| | - James Drover
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jacqueline Blundell
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada
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18
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Morosinotto C, Rainio M, Ruuskanen S, Korpimäki E. Antioxidant Enzyme Activities Vary with Predation Risk and Environmental Conditions in Free-Living Passerine Birds. Physiol Biochem Zool 2018; 91:837-848. [PMID: 29494281 DOI: 10.1086/697087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Prolonged physiological stress response may lead to an excessive production of reactive oxygen species (ROS) and ultimately to oxidative stress and severe fitness costs. We investigated whether natural variation in predation risk, induced by pygmy owls (Glaucidium passerinum), modifies the oxidative status of two free-living food-supplemented passerine bird species-the great tit (Parus major) and the willow tit (Poecile montanus)-in March 2012 and 2013. Predation risk significantly affected antioxidant enzyme activities of willow tits. Antioxidant enzyme activities (principal component factor 2 [PC2] representing glutathione-S-transferase and superoxide dismutase activities) were higher in high predation risk areas in 2013 than in low predation risk areas in the same year. Higher enzyme activities may suggest higher ROS production in birds living under high predation risk. In addition, antioxidant enzyme activities (PC2) were also higher in high predation risk areas in 2013 than in high predation risk areas in the previous year, 2012. This may represent variation in the risk represented by pygmy owls, which is probably inversely related to the natural fluctuations in the densities of their main prey, voles. In willow tits, PC1 (representing catalase, total glutathione, the ratio of reduced to oxidized glutathione, and protein carbonylation) was not affected by perceived predation risk, nor were antioxidant levels or enzyme activities in great tits. Higher enzyme activities observed in willow tits suggest that predator presence can modify the antioxidant status of avian prey, but the response also seem to be influenced by other environmental characteristics, like harsh winter conditions.
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19
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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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20
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Bleicher SS. The landscape of fear conceptual framework: definition and review of current applications and misuses. PeerJ 2017; 5:e3772. [PMID: 28929015 PMCID: PMC5600181 DOI: 10.7717/peerj.3772] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/16/2017] [Indexed: 11/24/2022] Open
Abstract
Landscapes of Fear (LOF), the spatially explicit distribution of perceived predation risk as seen by a population, is increasingly cited in ecological literature and has become a frequently used "buzz-word". With the increase in popularity, it became necessary to clarify the definition for the term, suggest boundaries and propose a common framework for its use. The LOF, as a progeny of the "ecology of fear" conceptual framework, defines fear as the strategic manifestation of the cost-benefit analysis of food and safety tradeoffs. In addition to direct predation risk, the LOF is affected by individuals' energetic-state, inter- and intra-specific competition and is constrained by the evolutionary history of each species. Herein, based on current applications of the LOF conceptual framework, I suggest the future research in this framework will be directed towards: (1) finding applied management uses as a trait defining a population's habitat-use and habitat-suitability; (2) studying multi-dimensional distribution of risk-assessment through time and space; (3) studying variability between individuals within a population; (4) measuring eco-neurological implications of risk as a feature of environmental heterogeneity and (5) expanding temporal and spatial scales of empirical studies.
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Affiliation(s)
- Sonny S. Bleicher
- Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, United States of America
- Tumamoc People and Habitat, Tumamoc Desert Research Laboratory, University of Arizona, United States of America
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21
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Oliveira TA, Idalencio R, Kalichak F, Dos Santos Rosa JG, Koakoski G, de Abreu MS, Giacomini ACV, Gusso D, Rosemberg DB, Barreto RE, Barcellos LJG. Stress responses to conspecific visual cues of predation risk in zebrafish. PeerJ 2017; 5:e3739. [PMID: 28890851 PMCID: PMC5588784 DOI: 10.7717/peerj.3739] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/04/2017] [Indexed: 11/20/2022] Open
Abstract
Chemical communication relating to predation risk is a trait common among fish species. Prey fish under threat of predation can signal risk to conspecific fish, which then exhibit defensive responses. Fish also assess predation risk by visual cues and change their behavior accordingly. Here, we explored whether these behavioral changes act as visual alarm signals to conspecific fish that are not initially under risk. We show that shoals of zebrafish (Danio rerio) visually exposed to a predator display antipredator behaviors. In addition, these defensive maneuvers trigger antipredator reactions in conspecifics and, concomitantly, stimulate the hypothalamus-pituitary-interrenal axis, leading to cortisol increase. Thus, we conclude that zebrafish defensive behaviors act as visual alarm cues that induce antipredator and stress response in conspecific fish.
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Affiliation(s)
- Thiago Acosta Oliveira
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Renan Idalencio
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Fabiana Kalichak
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | | | - Gessi Koakoski
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Murilo Sander de Abreu
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Ana Cristina Varrone Giacomini
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.,Bioscience Institute, Universidade de Passo Fundo, Passo Fundo, Brazil
| | - Darlan Gusso
- Department of Biologycal Sciences, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Denis Brook Rosemberg
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | | | - Leonardo José Gil Barcellos
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.,Programa de Pós-Graduação em Bioexperimentação, Universidade de Passo Fundo, Passo Fundo, Brazil
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22
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Stedman JM, Hallinger KK, Winkler DW, Vitousek MN. Heritable variation in circulating glucocorticoids and endocrine flexibility in a free‐living songbird. J Evol Biol 2017; 30:1724-1735. [DOI: 10.1111/jeb.13135] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 06/19/2017] [Accepted: 06/23/2017] [Indexed: 11/28/2022]
Affiliation(s)
- J. M. Stedman
- Department of Biomedical Sciences Cornell University Ithaca NY USA
| | - K. K. Hallinger
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
| | - D. W. Winkler
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
- Cornell Lab of Ornithology Ithaca NY USA
| | - M. N. Vitousek
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
- Cornell Lab of Ornithology Ithaca NY USA
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23
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Vitousek MN, Jenkins BR, Hubbard JK, Kaiser SA, Safran RJ. An experimental test of the effect of brood size on glucocorticoid responses, parental investment, and offspring phenotype. Gen Comp Endocrinol 2017; 247:97-106. [PMID: 28137535 DOI: 10.1016/j.ygcen.2017.01.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 01/20/2017] [Indexed: 02/02/2023]
Abstract
Because elevated glucocorticoid levels can impair reproduction, populations or species that engage in particularly valuable reproductive attempts may down-regulate the glucocorticoid stress response during reproduction (the brood value hypothesis). It is not clear, however, whether individuals rapidly modulate glucocorticoid responses based on shifting cues about the likelihood of reproductive success. By manipulating brood size to create broods that differed in potential value, we tested whether female barn swallows (Hirundo rustica) rapidly modulated the glucocorticoid stress response to promote investment in high-value broods, and whether nestling phenotype was influenced by treatment. Within-individual changes in female corticosterone, body mass, and measures of oxidative stress were unrelated to brood size treatment. Standard offspring provisioning rate did not differ across treatments; however, in the presence of a model predator, females raising enlarged broods maintained higher offspring feeding rates relative to control broods. Brood size did influence nestling phenotype. Nestlings from enlarged broods had lower body mass and higher baseline corticosterone than those from reduced broods. Finally, in adult females both baseline and stress-induced corticosterone were individually repeatable. Thus, while under moderately challenging environmental conditions brood size manipulations had context-dependent effects on parental investment, and influenced nestling phenotype, maternal glucocorticoid levels were not modulated based on brood value but were individually consistent features of phenotype during breeding.
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Affiliation(s)
- Maren N Vitousek
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA; Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA; Cornell Lab of Ornithology, Ithaca, NY 14850, USA.
| | - Brittany R Jenkins
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Joanna K Hubbard
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Sara A Kaiser
- Cornell Lab of Ornithology, Ithaca, NY 14850, USA; Center for Conservation Genomics, Smithsonian Institution, Washington, DC 20013, USA
| | - Rebecca J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
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24
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Ruuskanen S, Morosinotto C, Thomson RL, Ratnayake CP, Korpimäki E. Food supplementation, but not predation risk, alters female antioxidant status during breeding. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2299-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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25
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Walters BT, Cheng TNN, Doyle J, Guglielmo CG, Clinchy M, Zanette LY. Too important to tamper with: predation risk affects body mass and escape behaviour but not escape ability. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12851] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Benjamin T. Walters
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Tin Nok Natalie Cheng
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Justin Doyle
- Department of Computer Science University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Chistopher G. Guglielmo
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Michael Clinchy
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Liana Y. Zanette
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
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26
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Yin B, Yang S, Shang G, Wei W. Effects of predation risk on behavior, hormone levels, and reproductive success of plateau pikas. Ecosphere 2017. [DOI: 10.1002/ecs2.1643] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Baofa Yin
- College of Bioscience and Biotechnology; Yangzhou University; 12 Wenhui East Road Yangzhou Jiangsu 225009 China
| | - Shengmei Yang
- College of Bioscience and Biotechnology; Yangzhou University; 12 Wenhui East Road Yangzhou Jiangsu 225009 China
| | - Guozhen Shang
- College of Bioscience and Biotechnology; Yangzhou University; 12 Wenhui East Road Yangzhou Jiangsu 225009 China
| | - Wanhong Wei
- College of Bioscience and Biotechnology; Yangzhou University; 12 Wenhui East Road Yangzhou Jiangsu 225009 China
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27
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Gaitan J, Millien V. Stress level, parasite load, and movement pattern in a small-mammal reservoir host for Lyme disease. CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0225] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Occurrence of Lyme disease has increased rapidly in Canada in the past 5 years. The emergence of Lyme disease coincides with the range expansion of the primary host, the white-footed mouse (Peromyscus leucopus (Rafinesque, 1818)), in the region. We evaluated the effects of stress level, parasite load, and forest-patch characteristics on P. leucopus movement pattern. We found negative relations between on the one hand the adrenal gland size, a proxy for stress level, and population density, and on the other hand, home-range area and movement rate of mouse individuals, suggesting that stressed mice cannot maintain a large home range. Population density was also related with excursion (outside the forest patch) and exploration (outside the home range) rates, either directly or through its effect on home-range area and movement rate. Finally, movement rate and excursion rate were lower in individuals infested with more black-legged ticks (Ixodes scapularis Say, 1821). Our results have implication for the mechanism of Lyme disease emergence in the region: individual hosts that carry more ticks and are thus more likely to be spreading the bacterium responsible for Lyme disease are dispersing less than tick-free individuals. Monitoring of Lyme disease should thus consider how the characteristics of host communities modulate the spread of the disease across the landscape.
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Affiliation(s)
- J. Gaitan
- Redpath Museum, McGill University, 859 Sherbrooke West, Montréal, QC H3A 0C4, Canada
- Redpath Museum, McGill University, 859 Sherbrooke West, Montréal, QC H3A 0C4, Canada
| | - V. Millien
- Redpath Museum, McGill University, 859 Sherbrooke West, Montréal, QC H3A 0C4, Canada
- Redpath Museum, McGill University, 859 Sherbrooke West, Montréal, QC H3A 0C4, Canada
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28
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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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29
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Palacios MM, Killen SS, Nadler LE, White JR, McCormick MI. Top predators negate the effect of mesopredators on prey physiology. J Anim Ecol 2016; 85:1078-86. [PMID: 27113316 PMCID: PMC4999042 DOI: 10.1111/1365-2656.12523] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 03/12/2016] [Indexed: 11/28/2022]
Abstract
Predation theory and empirical evidence suggest that top predators benefit the survival of resource prey through the suppression of mesopredators. However, whether such behavioural suppression can also affect the physiology of resource prey has yet to be examined. Using a three-tier reef fish food web and intermittent-flow respirometry, our study examined changes in the metabolic rate of resource prey exposed to combinations of mesopredator and top predator cues. Under experimental conditions, the mesopredator (dottyback, Pseudochromis fuscus) continuously foraged and attacked resource prey (juveniles of the damselfish Pomacentrus amboinensis) triggering an increase in prey O2 uptake by 38 ± 12·9% (mean ± SE). The visual stimulus of a top predator (coral trout, Plectropomus leopardus) restricted the foraging activity of the mesopredator, indirectly allowing resource prey to minimize stress and maintain routine O2 uptake. Although not as strong as the effect of the top predator, the sight of a large non-predator species (thicklip wrasse, Hemigymnus melapterus) also reduced the impact of the mesopredator on prey metabolic rate. We conclude that lower trophic-level species can benefit physiologically from the presence of top predators through the behavioural suppression that top predators impose on mesopredators. By minimizing the energy spent on mesopredator avoidance and the associated stress response to mesopredator attacks, prey may be able to invest more energy in foraging and growth, highlighting the importance of the indirect, non-consumptive effects of top predators in marine food webs.
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Affiliation(s)
- Maria M Palacios
- ARC Centre of Excellence for Coral Reef Studies and College of Marine & Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia
| | - Shaun S Killen
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ, UK
| | - Lauren E Nadler
- ARC Centre of Excellence for Coral Reef Studies and College of Marine & Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia
| | - James R White
- ARC Centre of Excellence for Coral Reef Studies and College of Marine & Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia
| | - Mark I McCormick
- ARC Centre of Excellence for Coral Reef Studies and College of Marine & Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia
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30
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Jenkins BR, Vitousek MN, Hubbard JK, Safran RJ. An experimental analysis of the heritability of variation in glucocorticoid concentrations in a wild avian population. Proc Biol Sci 2015; 281:rspb.2014.1302. [PMID: 25056627 DOI: 10.1098/rspb.2014.1302] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Glucocorticoid hormones (CORT) are predicted to promote adaptation to variable environments, yet little is known about the potential for CORT secretion patterns to respond to selection in free-living populations. We assessed the heritable variation underlying differences in hormonal phenotypes using a cross-foster experimental design with nestling North American barn swallows (Hirundo rustica erythrogaster). Using a bivariate animal model, we partitioned variance in baseline and stress-induced CORT concentrations into their additive genetic and rearing environment components and estimated their genetic correlation. Both baseline and stress-induced CORT were heritable with heritability of 0.152 and 0.343, respectively. We found that the variation in baseline CORT was best explained by rearing environment, whereas the variation in stress-induced CORT was contributed to by a combination of genetic and environmental factors. Further, we did not detect a genetic correlation between these two hormonal traits. Although rearing environment appears to play an important role in the secretion of both types of CORT, our results suggest that stress-induced CORT levels are underlain by greater additive genetic variance compared with baseline CORT levels. Accordingly, we infer that the glucocorticoid response to stress has a greater potential for evolutionary change in response to selection compared with baseline glucocorticoid secretion patterns.
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Affiliation(s)
- Brittany R Jenkins
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Ramaley N122, UCB 334, Boulder, CO 80309, USA
| | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Ramaley N122, UCB 334, Boulder, CO 80309, USA
| | - Joanna K Hubbard
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Ramaley N122, UCB 334, Boulder, CO 80309, USA
| | - Rebecca J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Ramaley N122, UCB 334, Boulder, CO 80309, USA
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Morris DL, Faaborg J, Washburn BE, Millspaugh JJ. Predator-induced renesting and reproductive effort in indigo buntings: more work for less pay? CONSERVATION PHYSIOLOGY 2015; 3:cou063. [PMID: 27293684 PMCID: PMC4778466 DOI: 10.1093/conphys/cou063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 12/15/2014] [Accepted: 12/21/2014] [Indexed: 06/06/2023]
Abstract
Renesting after nest predation is ultimately an adaptive response to increase productivity in birds. However, renesting also increases reproductive effort to replace lost clutches. We investigated the consequences of this increased reproductive effort by determining whether renesting in female indigo buntings (Passerina cyanea) is associated with a decline in body condition (size-corrected mass) and haematocrit and an increase in stress hormones and whether renesting or maternal body condition is associated with a decline in productivity (clutch size, nestling body condition). Next, because a consequence of multiple renesting attempts is a prolonged breeding season and later timing, we predicted that a population of post-breeding females and juveniles would have lower body condition in fragmented forest than in contiguous forest owing to higher nest predation and frequency of renesting. Both forest types were settled by females of similar condition. Nest survival was lower in fragmented forest, where a higher proportion of females failed their first attempt and the breeding season was 2 weeks longer. Compared with females on their first attempt, renesting females had lower body condition and haematocrit and higher corticosterone concentrations. Lower maternal body condition was associated with higher concentrations of corticosterone, lower nestling body condition and smaller clutches. Clutch size was lower in renests and in fragmented forest. Nestling condition was lower in renests but did not vary greatly with forest type. Despite a prolonged breeding season in the fragmented forest, post-breeding females and hatch-year birds were in similar condition in both forest types. Our results suggest that the indirect effects of nest predation on maternal and offspring condition pose additional individual-level costs that have not been considered in the context of fragmentation studies. We discuss how predator-induced renesting could have additional demographic consequences by prolonging the breeding season and prompting seasonal interactions or carry-over effects that could impact populations.
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Affiliation(s)
- Dana L Morris
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO 65211, USA
- Division of Science, Mathematics and Computer Science, Central Methodist University, 411 Central Methodist Square, Fayette, MO 65248, USA
| | - John Faaborg
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO 65211, USA
| | - Brian E Washburn
- Department of Fisheries and Wildlife Sciences, University of Missouri, 302 Anheuser-Busch Natural Resources Building, Columbia, MO 65211, USA
- United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, 6100 Columbus Avenue, Sandusky, OH 44870, USA
| | - Joshua J Millspaugh
- Department of Fisheries and Wildlife Sciences, University of Missouri, 302 Anheuser-Busch Natural Resources Building, Columbia, MO 65211, USA
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Zanette LY, Clinchy M, Suraci JP. Diagnosing predation risk effects on demography: can measuring physiology provide the means? Oecologia 2014; 176:637-51. [PMID: 25234371 DOI: 10.1007/s00442-014-3057-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/18/2014] [Indexed: 11/30/2022]
Abstract
Predators kill prey thereby affecting prey survival and, in the traditional top-down view of predator limitation, that is their sole effect. Bottom-up food limitation alters the physiological condition of individuals affecting both fecundity and survival. Predators of course also scare prey inducing anti-predator defences that may carry physiological costs powerful enough to reduce prey fecundity and survival. Here, we consider whether measuring physiology can be used as a tool to unambiguously diagnose predation risk effects. We begin by providing a review of recent papers reporting physiological effects of predation risk. We then present a conceptual framework describing the pathways by which predators and food can affect prey populations and give an overview of predation risk effects on demography in various taxa. Because scared prey typically eat less the principal challenge we see will be to identify measures that permit us to avoid mistaking predator-induced reductions in food intake for absolute food shortage. To construct an effective diagnostic toolkit we advocate collecting multiple physiological measures and utilizing multivariate statistical procedures. We recommend conducting two-factor predation risk × food manipulations to identify those physiological effects least likely to be mistaken for responses to bottom-up food limitation. We suggest there is a critical need to develop a diagnostic tool that can be used when it is infeasible to experimentally test for predation risk effects on demography, as may often be the case in wildlife conservation, since failing to consider predation risk effects may cause the total impact of predators to be dramatically underestimated.
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Affiliation(s)
- Liana Y Zanette
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London, ON, N6A 5B7, Canada,
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33
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Jaatinen K, Seltmann MW, Öst M. Context-dependent stress responses and their connections to fitness in a landscape of fear. J Zool (1987) 2014. [DOI: 10.1111/jzo.12169] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Jaatinen
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
| | - M. W. Seltmann
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
| | - M. Öst
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
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34
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Caetano JVO, Maia MR, Manica LT, Macedo RH. Immune-related effects from predation risk in Neotropical blue-black grassquits (Volatinia jacarina). Behav Processes 2014; 109 Pt A:58-63. [PMID: 25038547 DOI: 10.1016/j.beproc.2014.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/08/2014] [Accepted: 07/08/2014] [Indexed: 11/17/2022]
Abstract
Predation is a major force shaping natural history traits of birds because of their vulnerability during nesting and higher visibility during diurnal activities. For most birds in the Neotropics, predation is the major cause of nest failure due to the region's high diversity and abundance of predators. The blue-black grassquit (Volatinia jacarina), similarly to other small passerines in the savanna region of central Brazil, suffers extremely high rates of nest predation. Additionally, males may be particularly vulnerable to predators since they are very conspicuous when executing courtship displays. We assessed some of the non-lethal costs of predation risk on this species by comparing physiological and morphological parameters of birds exposed to predator vocalizations with that of control subjects exposed to non-predator vocalizations. Birds exposed to the predator vocalizations exhibited an immune-related reaction (changes in their H/L ratio), but no changes were observed in other biological parameters measured. This article is part of a Special Issue entitled: Neotropical Behaviour.
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Affiliation(s)
- João V O Caetano
- Departamento de Zoologia - IB, Universidade de Brasília, Brasília, D.F. 70910-900, Brazil
| | - Maya R Maia
- Departamento de Zoologia - IB, Universidade de Brasília, Brasília, D.F. 70910-900, Brazil
| | - Lilian T Manica
- Departamento de Zoologia - IB, Universidade de Brasília, Brasília, D.F. 70910-900, Brazil
| | - Regina H Macedo
- Departamento de Zoologia - IB, Universidade de Brasília, Brasília, D.F. 70910-900, Brazil.
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Abstract
Behavioral, hormonal, and genetic processes interact reciprocally, and differentially affect behavior depending on ecological and social contexts. When individual differences are favored either between or within environments, developmental plasticity would be expected. Parental effects provide a rich source for phenotypic plasticity, including anatomical, physiological, and behavioral traits, because parents respond to dynamic cues in their environment and can, in turn, influence offspring accordingly. Because these inter-generational changes are plastic, parents can respond rapidly to changing environments and produce offspring whose phenotypes are well suited for current conditions more quickly than occurs with changes based on evolution through natural selection. I review studies on developmental plasticity and resulting phenotypes in Belding's ground squirrels (Urocitellus beldingi), an ideal species, given the competing demands to avoid predation while gaining sufficient weight to survive an upcoming hibernation, and the need for young to learn their survival behaviors. I will show how local environments and perceived risk of predation influence not only foraging, vigilance, and anti-predator behaviors, but also adrenal functioning, which may be especially important for obligate hibernators that face competing demands on the storage and mobilization of glucose. Mammalian behavioral development is sensitive to the social and physical environments provided by mothers during gestation and lactation. Therefore, maternal effects on offspring's phenotypes, both positive and negative, can be particularly strong.
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Affiliation(s)
- Jill M Mateo
- Department of Comparative Human Development, 5730 South Woodlawn Avenue, Chicago, IL 60637, USA
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36
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Fischer EK, Harris RM, Hofmann HA, Hoke KL. Predator exposure alters stress physiology in guppies across timescales. Horm Behav 2014; 65:165-72. [PMID: 24370688 DOI: 10.1016/j.yhbeh.2013.12.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 12/13/2013] [Accepted: 12/15/2013] [Indexed: 11/29/2022]
Abstract
In vertebrates, glucocorticoids mediate a wide-range of responses to stressors. For this reason, they are implicated in adaptation to changes in predation pressure. Trinidadian guppies (Poecilia reticulata) from high-predation environments have repeatedly and independently colonized and adapted to low-predation environments, resulting in parallel changes in life history, morphology, and behavior. We validated methods for non-invasive waterborne hormone sample collection in this species, and used this technique to examine genetic and environmental effects of predation on basal glucocorticoid (cortisol) levels. To examine genetic differences, we compared waterborne cortisol levels in high- and low-predation fish from two distinct population pairs. We found that fish from high-predation localities had lower cortisol levels than their low-predation counterparts. To isolate environmental influences, we compared waterborne cortisol levels in genetically similar fish reared with and without exposure to predator chemical cues. We found that fish reared with predator chemical cues had lower waterborne cortisol levels than those reared without. Comparisons of waterborne and whole-body cortisol levels demonstrated that populations differed in overall cortisol levels in the body, whereas rearing conditions altered the release of cortisol from the body into the water. Thus, evolutionary history with predators and lifetime exposure to predator cues were both associated with lower cortisol release, but depended on distinct physiological mechanisms.
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Affiliation(s)
- Eva K Fischer
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
| | - Rayna M Harris
- Department of Integrative Biology, Institute for Cellular & Molecular Biology, The University of Texas at Austin, 78712, USA
| | - Hans A Hofmann
- Department of Integrative Biology, Institute for Cellular & Molecular Biology, The University of Texas at Austin, 78712, USA; Institute for Neuroscience, The University of Texas at Austin, 78712, USA
| | - Kim L Hoke
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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37
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Jenkins BR, Vitousek MN, Safran RJ. Signaling stress? An analysis of phaeomelanin-based plumage color and individual corticosterone levels at two temporal scales in North American barn swallows, Hirundo rustica erythrogaster. Horm Behav 2013; 64:665-72. [PMID: 24013040 DOI: 10.1016/j.yhbeh.2013.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 08/16/2013] [Accepted: 08/20/2013] [Indexed: 02/03/2023]
Abstract
Sexually selected traits confer greater reproductive benefits to individuals with more elaborate forms of the signal. However, whether these signals convey reliable information about the physiology underlying trait development remains unknown in many species. The steroid hormone corticosterone (CORT) mediates important physiological and behavioral processes during the vertebrate stress response, and CORT secretion itself can be modulated by melanocortins. Thus, sexually selected melanin-based plumage coloration could function as an honest signal of an individual's ability to respond to stressors. This hypothesis was tested in North American barn swallows, Hirundo rustica erythrogaster, where males with darker ventral plumage color exhibit higher phaeomelanin content and are more successful at reproduction. Because reproductive behavior occurs months after plumage signals are developed, we also addressed the potential temporal disconnect of physiological state during trait development and trait advertisement by analyzing three different measurements of CORT levels in adult males during the breeding season (trait advertisement) and in nestling males while they were growing their feathers (trait development). Variation in adult plumage color did not predict baseline or stress-induced CORT, or stress responsiveness. Likewise, there was no relationship between nestling plumage color and any of the CORT measurements, but heavier nestlings had significantly lower baseline CORT. Our finding that a predominantly phaeomelanin-based trait is unrelated to circulating CORT suggests that phaeomelanin and eumelanin signals may convey different physiological information, and highlights the need for further study on the biochemical links between the hypothalamic-pituitary-adrenal (HPA) axis and the production of different melanin-based pigments.
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Affiliation(s)
- Brittany R Jenkins
- Department of Ecology and Evolutionary Biology, Ramaley N122, UCB 334, University of Colorado at Boulder, Boulder, CO 80309, USA.
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38
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Newman AEM, Zanette LY, Clinchy M, Goodenough N, Soma KK. Stress in the wild: chronic predator pressure and acute restraint affect plasma DHEA and corticosterone levels in a songbird. Stress 2013; 16:363-7. [PMID: 22934568 DOI: 10.3109/10253890.2012.723076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effects of chronic stressors on glucocorticoid levels are well described in laboratory rodents, but far less is known about the effects of chronic stressors on wild animals or on dehydroepiandrosterone (DHEA) levels. DHEA can be produced by the adrenal cortex and has prominent antiglucocorticoid properties. Here, we examined wild songbirds to elucidate the relationship between chronic predator pressure and plasma DHEA and corticosterone levels. We measured circulating steroid levels at baseline and after acute restraint in the breeding and nonbreeding seasons. During the breeding season, males in low predator pressure (LPP) environments had higher baseline DHEA levels than males in high predator pressure (HPP) environments. Also, acute restraint decreased DHEA levels in LPP males only but increased corticosterone levels in HPP and LPP males similarly. During the nonbreeding season, DHEA and corticosterone levels were lower than during the breeding season, and acute restraint decreased DHEA levels in both HPP and LPP males. Unlike males, breeding females showed no effect of predator pressure on baseline DHEA or corticosterone levels. These data suggest that naturalistic chronic and acute stressors affect circulating DHEA and corticosterone levels in wild animals and highlight the importance of using multiple endpoints when studying the physiological effects of chronic stress.
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Affiliation(s)
- A E M Newman
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada.
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39
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Middlemis Maher J, Werner EE, Denver RJ. Stress hormones mediate predator-induced phenotypic plasticity in amphibian tadpoles. Proc Biol Sci 2013; 280:20123075. [PMID: 23466985 DOI: 10.1098/rspb.2012.3075] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Amphibian tadpoles display extensive anti-predator phenotypic plasticity, reducing locomotory activity and, with chronic predator exposure, developing relatively smaller trunks and larger tails. In many vertebrates, predator exposure alters activity of the neuroendocrine stress axis. We investigated predator-induced effects on stress hormone production and the mechanistic link to anti-predator defences in Rana sylvatica tadpoles. Whole-body corticosterone (CORT) content was positively correlated with predator biomass in natural ponds. Exposure to caged predators in mesocosms caused a reduction in CORT by 4 hours, but increased CORT after 4 days. Tadpoles chronically exposed to exogenous CORT developed larger tails relative to their trunks, matching morphological changes induced by predator chemical cue; this predator effect was blocked by the corticosteroid biosynthesis inhibitor metyrapone. Tadpole tail explants treated in vitro with CORT increased tissue weight, suggesting that CORT acts directly on the tail. Short-term treatment of tadpoles with CORT increased predation mortality, likely due to increased locomotory activity. However, long-term CORT treatment enhanced survivorship, likely due to induced morphology. Our findings support the hypothesis that tadpole physiological and behavioural/morphological responses to predation are causally interrelated. Tadpoles initially suppress CORT and behaviour to avoid capture, but increase CORT with longer exposure, inducing adaptive phenotypic changes.
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Affiliation(s)
- Jessica Middlemis Maher
- Department of Ecology and Evolutionary Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA.
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40
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Pakkala JJ, Norris DR, Newman AEM. An Experimental Test of the Capture-Restraint Protocol for Estimating the Acute Stress Response. Physiol Biochem Zool 2013; 86:279-84. [DOI: 10.1086/668893] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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41
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Food use is affected by the experience of nest predation: implications for indirect predator effects on clutch size. Oecologia 2013; 172:1031-9. [DOI: 10.1007/s00442-012-2570-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 12/14/2012] [Indexed: 10/27/2022]
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42
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Breuner CW, Delehanty B, Boonstra R. Evaluating stress in natural populations of vertebrates: total CORT is not good enough. Funct Ecol 2012. [DOI: 10.1111/1365-2435.12016] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Creagh W. Breuner
- Wildlife Biology and Organismal Biology and Ecology; University of Montana; Missoula; Montana; 59812; USA
| | - Brendan Delehanty
- Department of Biological Sciences; Centre for the Neurobiology of Stress; University of Toronto Scarborough; Toronto; Ontario; M1C 1A4; Canada
| | - Rudy Boonstra
- Department of Biological Sciences; Centre for the Neurobiology of Stress; University of Toronto Scarborough; Toronto; Ontario; M1C 1A4; Canada
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43
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Affiliation(s)
- Michael Clinchy
- Department of Biology; University of Victoria; Victoria; British Columbia; V8W 3N5; Canada
| | - Michael J. Sheriff
- Institute of Arctic Biology; University of Alaska Fairbanks; Fairbanks; Alaska; 99775; USA
| | - Liana Y. Zanette
- Department of Biology; University of Western Ontario; London; Ontario; N6A 5B7; Canada
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44
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Developmental fluoxetine exposure differentially alters central and peripheral measures of the HPA system in adolescent male and female offspring. Neuroscience 2012; 220:131-41. [DOI: 10.1016/j.neuroscience.2012.06.034] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 05/27/2012] [Accepted: 06/13/2012] [Indexed: 11/20/2022]
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45
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Creel S, Dantzer B, Goymann W, Rubenstein DR. The ecology of stress: effects of the social environment. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.02029.x] [Citation(s) in RCA: 326] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Scott Creel
- Conservation Biology & Ecology Program; Department of Ecology; Montana State University; Bozeman; Montana; 59717; USA
| | - Ben Dantzer
- Department of Zoology; Michigan State University; East Lansing; Michigan; 48824; USA
| | - Wolfgang Goymann
- Abteilung Verhaltensneurobiologie; Max-Planck-Institut für Ornithologie; Eberhard-Gwinner-Straße; Haus 6a; D-82319; Seewiesen; Germany
| | - Dustin R. Rubenstein
- Department of Ecology, Evolution and Environmental Biology; Columbia University; 10th Floor Schermerhorn Extension; MC 5557; 1200 Amsterdam Avenue; New York; New York; 10027; USA
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46
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Sheriff MJ, Wheeler H, Donker SA, Krebs CJ, Palme R, Hik DS, Boonstra R. Mountain-top and valley-bottom experiences: the stress axis as an integrator of environmental variability in arctic ground squirrel populations. J Zool (1987) 2012. [DOI: 10.1111/j.1469-7998.2011.00888.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - S. A. Donker
- Department of Zoology; University of British Columbia; Vancouver; BC; Canada
| | - C. J. Krebs
- Department of Zoology; University of British Columbia; Vancouver; BC; Canada
| | - R. Palme
- Department of Biomedical Sciences/Biochemistry; University of Veterinary Medicine; Vienna; Austria
| | - D. S. Hik
- Department of Biological Sciences; University of Alberta; Edmonton; AB; Canada
| | - R. Boonstra
- Centre for the Neurobiology of Stress; University of Toronto Scarborough; Toronto; ON; Canada
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47
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Clinchy M, Schulkin J, Zanette LY, Sheriff MJ, McGowan PO, Boonstra R. The Neurological Ecology of Fear: Insights Neuroscientists and Ecologists Have to Offer one Another. Front Behav Neurosci 2011; 4:21. [PMID: 21629856 PMCID: PMC3084442 DOI: 10.3389/fnbeh.2011.00021] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 04/09/2011] [Indexed: 11/13/2022] Open
Abstract
That the fear and stress of life-threatening experiences can leave an indelible trace on the brain is most clearly exemplified by post-traumatic stress disorder (PTSD). Many researchers studying the animal model of PTSD have adopted utilizing exposure to a predator as a life-threatening psychological stressor, to emulate the experience in humans, and the resulting body of literature has demonstrated numerous long-lasting neurological effects paralleling those in PTSD patients. Even though much more extreme, predator-induced fear and stress in animals in the wild was, until the 1990s, not thought to have any lasting effects, whereas recent experiments have demonstrated that the effects on free-living animals are sufficiently long-lasting to even affect reproduction, though the lasting neurological effects remain unexplored. We suggest neuroscientists and ecologists both have much to gain from collaborating in studying the neurological effects of predator-induced fear and stress in animals in the wild. We outline the approaches taken in the lab that appear most readily translatable to the field, and detail the advantages that studying animals in the wild can offer researchers investigating the "predator model of PTSD."
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Affiliation(s)
- Michael Clinchy
- Department of Biology, University of Victoria Victoria, BC, Canada
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