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Alaasam VJ, Behnke TL, Grant AR, Ouyang JQ. Glucocorticoids and land cover: a largescale comparative approach to assess a physiological biomarker for avian conservation. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220508. [PMID: 38310940 PMCID: PMC10838646 DOI: 10.1098/rstb.2022.0508] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/19/2023] [Indexed: 02/06/2024] Open
Abstract
As humans alter landscapes worldwide, land and wildlife managers need reliable tools to assess and monitor responses of wildlife populations. Glucocorticoid (GC) hormone levels are one common physiological metric used to quantify how populations are coping in the context of their environments. Understanding whether GC levels can reflect broad landscape characteristics, using data that are free and commonplace to diverse stakeholders, is an important step towards physiological biomarkers having practical application in management and conservation. We conducted a phylogenetic comparative analysis using publicly available datasets to test the efficacy of GCs as a biomarker for large spatial-scale avian population monitoring. We used hormone data from HormoneBase (51 species), natural history information and US national land cover data to determine if baseline or stress-induced corticosterone varies with the amount of usable land cover types within each species' home range. We found that stress-induced levels, but not baseline, positively correlated with per cent usable land cover both within and across species. Our results indicate that GC concentrations may be a useful biomarker for characterizing populations across a range of habitat availability, and we advocate for more physiological studies on non-traditional species in less studied populations to build on this framework. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.
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Affiliation(s)
| | - Tessa L. Behnke
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV 89557, USA
| | - Avery R. Grant
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Jenny Q. Ouyang
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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2
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Byrd AJ, Talbott KM, Smiley TM, Verrett TB, Gross MS, Hladik ML, Ketterson ED, Becker DJ. Determinants of spring migration departure dates in a New World sparrow: Weather variables reign supreme. Ecol Evol 2024; 14:e10874. [PMID: 38390000 PMCID: PMC10883105 DOI: 10.1002/ece3.10874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/30/2023] [Accepted: 01/08/2024] [Indexed: 02/24/2024] Open
Abstract
Numerous factors influence the timing of spring migration in birds, yet the relative importance of intrinsic and extrinsic variables on migration initiation remains unclear. To test for interactions among weather, migration distance, parasitism, and physiology in determining spring departure date, we used the Dark-eyed Junco (Junco hyemalis) as a model migratory species known to harbor diverse and common haemosporidian parasites. Prior to spring migration departure from their wintering grounds in Indiana, USA, we quantified the intrinsic variables of fat, body condition (i.e., mass ~ tarsus residuals), physiological stress (i.e., ratio of heterophils to lymphocytes), cellular immunity (i.e., leukocyte composition and total count), migration distance (i.e., distance to the breeding grounds) using stable isotopes of hydrogen from feathers, and haemosporidian parasite intensity. We then attached nanotags to determine the timing of spring migration departure date using the Motus Wildlife Tracking System. We used additive Cox proportional hazard mixed models to test how risk of spring migratory departure was predicted by the combined intrinsic measures, along with meteorological predictors on the evening of departure (i.e., average wind speed and direction, relative humidity, and temperature). Model comparisons found that the best predictor of spring departure date was average nightly wind direction and a principal component combining relative humidity and temperature. Juncos were more likely to depart for spring migration on nights with largely southwestern winds and on warmer and drier evenings (relative to cooler and more humid evenings). Our results indicate that weather conditions at take-off are more critical to departure decisions than the measured physiological and parasitism variables.
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Affiliation(s)
- Allison J Byrd
- Environmental Resilience Institute Indiana University Bloomington Indiana USA
- Department of Biology Indiana University Bloomington Indiana USA
| | | | - Tara M Smiley
- Department of Ecology and Evolution Stony Brook University Stony Brook New York USA
| | - Taylor B Verrett
- School of Biological Sciences University of Oklahoma Norman Oklahoma USA
| | - Michael S Gross
- U.S. Geological Survey California Water Science Center Sacramento California USA
| | - Michelle L Hladik
- U.S. Geological Survey California Water Science Center Sacramento California USA
| | - Ellen D Ketterson
- Environmental Resilience Institute Indiana University Bloomington Indiana USA
- Department of Biology Indiana University Bloomington Indiana USA
| | - Daniel J Becker
- School of Biological Sciences University of Oklahoma Norman Oklahoma USA
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3
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Marasco V, Kaiya H, Pola G, Fusani L. Ghrelin, not corticosterone, is associated with transitioning of phenotypic states in a migratory Galliform. Front Endocrinol (Lausanne) 2023; 13:1058298. [PMID: 36699038 PMCID: PMC9869107 DOI: 10.3389/fendo.2022.1058298] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/28/2022] [Indexed: 01/12/2023] Open
Abstract
In both captive and free-living birds, the emergence of the migratory phenotype is signalled by rapid and marked increases in food intake and fuelling, as well as changes in amount of nocturnality or migratory restlessness. The metabolic hormone corticosterone and, as more recently suggested, the gut-derived hormone ghrelin have been suggested to play a role in mediating such phenomenal phenotypic flexibility given that they both regulate fuel metabolism and locomotion across vertebrate taxa. Here, using the Common quail (Coturnix coturnix) as our study species, we induced autumn migration followed by a non-migratory wintering phase through controlled changes in daylight. We thus compared plasma corticosterone and ghrelin concentrations between the two sampling phases and assessed whether these hormones might reflect the migratory state. While we found no differences in plasma corticosterone between the two sampling phases and no link of this hormone with changes in body mass, levels of food intake or migratory restlessness, the migratory birds had substantially higher levels of plasma ghrelin relative to the non-migratory birds. Furthermore, while ghrelin did not correlate with the gain in body mass over the entire pre-migratory fuelling phase (over an average of nine weeks preceding blood sampling), plasma ghrelin did positively correlate with the gain in body mass observed during the final fattening stages (over an average of three weeks preceding blood sampling). Again, variation in plasma ghrelin also reflected the amount of body mass depleted over both the long- and short-time frame as birds returned to their non-migratory baseline - lower levels of plasma ghrelin consistently correlated with larger losses in body mass. Thus, while our data do not highlight a role of the hormone corticosterone in sustaining pre-migratory fattening as shown in other bird species, they do add evidence for a potential role of ghrelin in mediating migratory behaviour and further suggest that this hormone might be important in regulating the transitioning of migratory states, possibly by promoting fuel mobilisation and usage.
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Affiliation(s)
- Valeria Marasco
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
- Research Division of Drug Discovery, Grandsoul Research Institute for Immunology, Inc., Nara, Japan
| | - Gianni Pola
- Istituto Sperimentale Zootecnico per la Sicilia, Palermo, Italy
| | - Leonida Fusani
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Vienna, Austria
- Department of Behavioural and Cognitive Biology, University Biology Building, University of Vienna, Vienna, Austria
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4
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Bottini CLJ, Whiley RE, Branfireun BA, MacDougall-Shackleton SA. Effects of methylmercury and food stress on migratory activity in song sparrows, Melospiza melodia. Horm Behav 2022; 146:105261. [PMID: 36126358 DOI: 10.1016/j.yhbeh.2022.105261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 11/25/2022]
Abstract
Avian migration is a challenging life stage susceptible to the adverse effects of stressors, including contaminants like methylmercury (MeHg). Although birds often experience stressors and contaminants concurrently in the wild, no study to date has investigated how simultaneous exposure to MeHg and food stress affects migratory behavior. Our objectives were to determine if MeHg or food stress exposure during summer, alone or combined, has carry-over effects on autumn migratory activity, and if hormone levels (corticosterone, thyroxine) and body condition were related to these effects. We tested how exposure to dietary MeHg and/or food stress (unpredictable temporary food removal) affected migratory behavior in captive song sparrows, Melospiza melodia. Nocturnal activity was influenced by a 3-way interaction between MeHg × stress × nights of the study, indicating that activity changed over time in different ways depending on prior treatments. Thyroxine was not affected by treatment or sampling date. During the migratory season, fecal corticosterone metabolite concentrations increased in birds co-exposed to MeHg and food stress compared to controls, suggesting an additive carry-over effect. As well, during the period of behavioral recording, body condition increased with time in unstressed birds, but not in stressed birds. Fecal corticosterone metabolite concentrations were positively correlated to duration of nocturnal activity, but thyroxine levels and body condition were not. The differences in nocturnal activity between groups suggest that food stress and MeHg exposure on breeding grounds could have direct and indirect carry-over effects that have the potential to affect the fall migration journey.
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Affiliation(s)
- Claire L J Bottini
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada.
| | - Rebecca E Whiley
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Brian A Branfireun
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada
| | - Scott A MacDougall-Shackleton
- Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada; University of Western Ontario, Department of Psychology, 1151 Richmond St., London, Ontario N6A 5C2, Canada
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5
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Bauer CM, Watts HE. Corticosterone's roles in avian migration: Assessment of three hypotheses. Horm Behav 2021; 135:105033. [PMID: 34273707 DOI: 10.1016/j.yhbeh.2021.105033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/30/2021] [Accepted: 07/03/2021] [Indexed: 12/30/2022]
Abstract
While corticosterone (CORT) is often suggested to be an important hormone regulating processes necessary for avian migration, there has been no systematic assessment of CORT's role in migration. Prior to migration, birds increase fat stores and flight muscle size to prepare for the high energetic costs associated with long-distance flight. After attaining sufficient energetic stores, birds then make the actual decision to depart from their origin site. Once en route birds alternate between periods of flight and stopovers, during which they rest and refuel for their next bouts of endurance flight. Here, we evaluate three non-mutually exclusive hypotheses that have been proposed in the literature for CORT's role in migration. (1) CORT facilitates physiological preparations for migration [e.g. hyperphagia, fattening, and flight muscle hypertrophy]. (2) CORT stimulates departure from origin or stopover sites. (3) CORT supports sustained migratory travel. After examining the literature to test predictions stemming from each of these three hypotheses, we found weak support for a role of CORT in physiological preparation for migration. However, we found moderate support for a role of CORT in stimulating departures, as CORT increases immediately prior to departure and is higher when migratory restlessness is displayed. We also found moderate support for the hypothesis that CORT helps maintain sustained travel, as CORT is generally higher during periods of flight, though few studies have tested this hypothesis. We provide recommendations for future studies that would help to further resolve the role of CORT in migration.
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Affiliation(s)
- Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA, USA.
| | - Heather E Watts
- School of Biological Sciences, Washington State University, Pullman, WA, USA; Center for Reproductive Biology, Washington State University, Pullman, WA, USA
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6
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Extrinsic factors, endocrine mechanisms, and behavioral indicators of migratory restlessness in wintering whooper swans (Cygnus cygnus). Sci Rep 2021; 11:12636. [PMID: 34135395 PMCID: PMC8209029 DOI: 10.1038/s41598-021-92031-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 05/21/2021] [Indexed: 11/24/2022] Open
Abstract
Extrinsic factors, endocrine mechanisms, and behavioral indicators of migratory restlessness were studied in wintering whooper swans (Cygnus cygnus) in the Sanmenxia Swan National Wetland Park in western Henan Province, central China. First, the fecal glucocorticoid metabolite (FGM) concentration was established and related to mean air temperature or photo period (day length) using simple linear or non-linear regression models. After a model selection procedure, the best fitted model revealed that an increase of FGM concentration was associated with an increase in the squared mean air temperature (R2 = 0.88). Other models showed an increasing FGM concentration to correspond with increasing values of day length, squared day length, and mean air temperature—however without statistical support. In a second step, behavioral frequencies of seven behaviors were condensed into three behavioral principal components (PCs) using principal components analysis. Behavioral PCs largely corresponded to three activity phases described for wintering whooper swans in central China and were correlated with the FGM concentration using Spearman's rank-order correlations. Results revealed a significant correlation between FGM and behavioral PC2 (positive factor loadings from vigilance and preening, negative loading from foraging). Finally, we tested for an effect of behavioral PCs on changes in winter home range size using a set of multiple linear regression models. Results of averaged model parameter estimates showed only the behavioral PC3 (positive factor loadings from fighting and calling, negative loading from locomotion) had a marginal significant effect on home range size. Results confirmed findings of previous studies on migratory restlessness in whooper swans. However, due to the small sample size (N = 15 weeks) the effect of PC3 on home range size was weak and should be viewed with caution.
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7
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DeSimone JG, Tobalske BW, Breuner CW. Physiology and behavior under food limitation support an escape, not preparative, response in the nomadic pine siskin ( Spinus pinus). J Exp Biol 2021; 224:jeb238774. [PMID: 33376142 DOI: 10.1242/jeb.238774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 12/18/2020] [Indexed: 11/20/2022]
Abstract
Migration allows animals to use resources that are variable in time and/or space, with different migratory strategies depending on the predictability of resource variation. When food varies seasonally, obligate migrants anticipate and prepare for migration. In contrast, facultative migrants, whose movements are unpredictable in timing and destination, may prepare for either migration or escape when resources are depleted. We propose and test two alternative hypotheses regarding the behavioral and physiological responses of facultative migrants to declining food availability. (1) The prepare hypothesis predicts that facultative migrants prepare for departure by increasing fuel stores in response to declining food availability, and elevations of baseline corticosterone (CORT) facilitate increased activity. (2) The escape hypothesis predicts that facultative migrants do not prepare for departure, body condition declines as food availability declines, and stress-induced levels of CORT induce escape behavior when both energetic condition and food resources are low. We conducted a 16-day experiment, measuring body composition (using quantitative magnetic resonance), activity (using force perches) and baseline CORT in pine siskins (Spinus pinus) given ad libitum food or a slow decline, fast decline or randomly changing amount of food. Our results support the escape hypothesis: body condition declined as food declined, decreases in body and fat mass were associated with increases in baseline CORT, and activity increased only when food availability was low. This work suggests that facultative migration in autumn allows birds to escape low-resource areas and that the underlying physiological mechanisms differ from those driving both seasonal, obligate migrations and spring nomadic movements.
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Affiliation(s)
- Joely G DeSimone
- Ecology and Evolution, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Bret W Tobalske
- Ecology and Evolution, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Creagh W Breuner
- Ecology and Evolution, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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8
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Casagrande S, DeMoranville KJ, Trost L, Pierce B, Bryła A, Dzialo M, Sadowska ET, Bauchinger U, McWilliams SR. Dietary antioxidants attenuate the endocrine stress response during long-duration flight of a migratory bird. Proc Biol Sci 2020; 287:20200744. [PMID: 32546088 PMCID: PMC7329026 DOI: 10.1098/rspb.2020.0744] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/21/2020] [Indexed: 12/12/2022] Open
Abstract
Glucocorticoids (GCs) are metabolic hormones that promote catabolic processes, which release stored energy and support high metabolic demands such as during prolonged flights of migrating birds. Dietary antioxidants (e.g. anthocyanins) support metabolism by quenching excess reactive oxygen species produced during aerobic metabolism and also by activating specific metabolic pathways. For example, similar to GCs' function, anthocyanins promote the release of stored energy, although the extent of complementarity between GCs and dietary antioxidants is not well known. If anthocyanins complement GCs functions, birds consuming anthocyanin-rich food can be expected to limit the secretion of GCs when coping with a metabolically challenging activity, avoiding the exposure to potential hormonal detrimental effects. We tested this hypothesis in European starlings (Sturnus vulgaris) flying in a wind tunnel. We compared levels of corticosterone, the main avian GC, immediately after a sustained flight and at rest for birds that were fed diets with or without an anthocyanin supplement. As predicted, we found (i) higher corticosterone after flight than at rest in both diet groups and (ii) anthocyanin-supplemented birds had less elevated corticosterone after flight than unsupplemented control birds. This provides novel evidence that dietary antioxidants attenuate the activation of the HPA axis (i.e. increased secretion of corticosterone) during long-duration flight.
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Affiliation(s)
- Stefania Casagrande
- Evolutionary Physiology Research Group, Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany
| | - Kristen J DeMoranville
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Lisa Trost
- Department for Behavioral Neurobiology, Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany
| | - Barbara Pierce
- Department of Biology, Sacred Heart University, Fairfield, CT 06825, USA
| | - Amadeusz Bryła
- Institute of Environmental Sciences, Jagiellonian University, 30-387 Kraków, Poland
| | - Maciej Dzialo
- Institute of Environmental Sciences, Jagiellonian University, 30-387 Kraków, Poland
| | - Edyta T Sadowska
- Institute of Environmental Sciences, Jagiellonian University, 30-387 Kraków, Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences, Jagiellonian University, 30-387 Kraków, Poland
- Nencki Institute of Experimental Biology, PAS, 02-093 Warsaw, Poland
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
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Ferretti A, McWilliams SR, Rattenborg NC, Maggini I, Cardinale M, Fusani L. Energy Stores, Oxidative Balance, and Sleep in Migratory Garden Warblers ( Sylvia borin) and Whitethroats ( Sylvia communis) at a Spring Stopover Site. Integr Org Biol 2020; 2:obaa010. [PMID: 33791554 PMCID: PMC7671129 DOI: 10.1093/iob/obaa010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Little is known about how songbirds modulate sleep during migratory periods. Due to the alternation of nocturnal endurance flights and diurnal refueling stopovers, sleep is likely to be a major constraint for many migratory passerine species. Sleep may help to increase the endogenous antioxidant capacity that counteracts free radicals produced during endurance flight and reduces energy expenditure. Here, we investigated the relationship between sleep behavior, food intake, and two markers of physiological condition-the amount of energy reserves and oxidative status-in two migratory songbird species, the garden warbler (Sylvia borin) and the whitethroat (Sylvia communis). In garden warblers, birds with high energy stores were more prone to sleep during the day, while this condition-dependent sleep pattern was not present in whitethroats. In both species, birds with low energy stores were more likely to sleep with their head tucked in the feathers during nocturnal sleep. Moreover, we found a positive correlation between food intake and the extent of energy reserves in garden warblers, but not in whitethroats. Finally, we did not find significant correlations between oxidative status and sleep, or oxidative status and energy stores. Despite our study was not comparative, it suggests that different species might use different strategies to manage their energy during stopover and, additionally, it raises the possibility that migrants have evolved physiological adaptations to deal with oxidative damage produced during migration.
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Affiliation(s)
- Andrea Ferretti
- Department of Behavioural and Cognitive Biology, University of Vienna, Althanstraße 14 (UZA1), Wien 1090, Austria
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstraße 1a, Wien 1160, Austria
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, 1 Greenhouse Road, Kingston, RI 02881, USA
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Eberhard-Gwinner-Straße, Seewiesen 8231, Germany
| | - Ivan Maggini
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstraße 1a, Wien 1160, Austria
| | - Massimiliano Cardinale
- Marine Research Institute, Swedish University of Agricultural Sciences, Turistgatan 5, Lysekil SE-453 30, Sweden
| | - Leonida Fusani
- Department of Behavioural and Cognitive Biology, University of Vienna, Althanstraße 14 (UZA1), Wien 1090, Austria
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstraße 1a, Wien 1160, Austria
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10
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Eikenaar C, Winslott E, Hessler S, Isaksson C. Oxidative damage to lipids is rapidly reduced during migratory stopovers. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13540] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research Wilhelmshaven Germany
| | | | - Sven Hessler
- Institute of Avian Research Wilhelmshaven Germany
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11
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Eikenaar C, Hessler S, Hegemann A. Migrating birds rapidly increase constitutive immune function during stopover. ROYAL SOCIETY OPEN SCIENCE 2020; 7:192031. [PMID: 32257353 PMCID: PMC7062082 DOI: 10.1098/rsos.192031] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/06/2020] [Indexed: 06/01/2023]
Abstract
Migratory flight is physiologically highly demanding and has been shown to negatively affect multiple parameters of constitutive immune function (CIF), an animal's first line of physiological defence against infections. In between migratory flights, most birds make stopovers, periods during which they accumulate fuel for the next flight(s). Stopovers are also commonly thought of as periods of rest and recovery, but what this encompasses is largely undefined. Here, we show that during stopover, northern wheatears Oenanthe oenanthe, a long-distance migratory bird, can rapidly increase constitutive innate immune function. We caught and temporarily caged birds under ad libitum food conditions at a stopover site in autumn. Within 2 days, most birds significantly increased complement activity and their ability to kill microbes. Changes in immune function were not related to the birds' food intake or extent of fuel accumulation. Our study suggests that stopovers may not only be important to refuel but also to restore immune function. Additionally, the increase in CIF could help migrating birds to deal with novel pathogens they may encounter at stopover sites.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Sven Hessler
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Arne Hegemann
- Department of Biology, Lund University, Ecology Building, Lund 223 62, Sweden
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12
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Individual differences in glucocorticoid regulation: Does it relate to disease risk and resilience? Front Neuroendocrinol 2020; 56:100803. [PMID: 31697962 PMCID: PMC7189329 DOI: 10.1016/j.yfrne.2019.100803] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/03/2019] [Accepted: 10/29/2019] [Indexed: 12/17/2022]
Abstract
Glucocorticoid (GC) signaling varies among individuals, and this variation may relate to individual differences in health outcomes. To determine if and which aspects of signaling (basal, circadian, integrative, or reactivity) are associated with specific health outcomes, we reviewed recent studies that relate GCs to health outcomes. We identified papers through PubMed and reviewed 100 original research articles related to mental health, cardiovascular health, cancer, diabetes, obesity, pulmonary health, sleep, and fitness. Many studies reported elevated GC secretion associated with worse health, but this was only particularly true for integrative GC measures. On the other hand, accentuated cortisol awakening response and a steeper circadian rhythm were both associated with positive health outcomes. Overall, relationships between GC secretion and health outcomes were relatively weak. This systematic review of relationships between GC metrics and health outcomes highlights the importance of careful consideration when selecting methods to measure GC regulation in health research.
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13
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Pradhan DS, Van Ness R, Jalabert C, Hamden JE, Austin SH, Soma KK, Ramenofsky M, Schlinger BA. Phenotypic flexibility of glucocorticoid signaling in skeletal muscles of a songbird preparing to migrate. Horm Behav 2019; 116:104586. [PMID: 31473198 DOI: 10.1016/j.yhbeh.2019.104586] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 02/01/2023]
Abstract
Glucocorticoids are commonly associated with responses to stress, but other important functions include homeostatic regulation, energy metabolism and tissue remodeling. At low circulating levels, glucocorticoids bind to high-affinity mineralocorticoid receptors (MR) to activate tissue repair and homeostasis (anabolic pathways), whereas at elevated levels, glucocorticoids bind to glucocorticoid receptors (GR) to activate catabolic pathways. Long distance migrations, such as those performed by Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii), require modification of anatomy, physiology and behavior. Plasma corticosterone (CORT) increases in association with impending departure and flight and may promote muscle-specific anabolic states. To test this idea, we explored glucocorticoid signaling in the pectoralis (flight) and gastrocnemius (leg) muscles of male sparrows on the wintering grounds at three stages leading up to spring departure: winter (February), pre-nuptial molt (March), and pre-departure (April). CORT was detected in plasma and in both muscles, but measures of CORT signaling differed across muscles and stages. Expression of 11β-hydroxysteroid dehydrogenase (11β-HSD) Type 2 (inactivates CORT) increased in the pectoralis at pre-departure, whereas 11β-HSD Type 1 (regenerates CORT) did not change. Neither of the two 11β-HSD isoforms was detectable in the gastrocnemius. Expression of MR, but not GR, was elevated in the pectoralis at pre-departure, while only GR expression was elevated at pre-nuptial molt in gastrocnemius. These data suggest that anabolic functions predominate in the pectoralis only while catabolic activity is undetected in either muscle at pre-departure.
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Affiliation(s)
- Devaleena S Pradhan
- Department of Integrative Biology and Physiology, University of California, Los Angeles, United States of America; Laboratory for Neuroendocrinology, University of California, Los Angeles, United States of America.
| | - Raymond Van Ness
- Department of Integrative Biology and Physiology, University of California, Los Angeles, United States of America
| | - Cecilia Jalabert
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Jordan E Hamden
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Suzanne H Austin
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, United States of America
| | - Kiran K Soma
- Department of Zoology, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada; Department of Psychology, University of British Columbia, Vancouver, Canada
| | - Marilyn Ramenofsky
- Department of Neurobiology, Physiology, Behavior, University of California, Davis, United States of America
| | - Barney A Schlinger
- Department of Integrative Biology and Physiology, University of California, Los Angeles, United States of America; Laboratory for Neuroendocrinology, University of California, Los Angeles, United States of America; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, United States of America
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14
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Tomotani BM, de la Hera I, Lange CYMJG, van Lith B, Meddle SL, Both C, Visser ME. Timing manipulations reveal the lack of a causal link across timing of annual-cycle stages in a long-distance migrant. ACTA ACUST UNITED AC 2019; 222:jeb.201467. [PMID: 31413104 DOI: 10.1242/jeb.201467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/08/2019] [Indexed: 11/20/2022]
Abstract
Organisms need to time their annual-cycle stages, like breeding and migration, to occur at the right time of the year. Climate change has shifted the timing of annual-cycle stages at different rates, thereby tightening or lifting time constraints of these annual-cycle stages, a rarely studied consequence of climate change. The degree to which these constraints are affected by climate change depends on whether consecutive stages are causally linked (scenario I) or whether the timing of each stage is independent of other stages (scenario II). Under scenario I, a change in timing in one stage has knock-on timing effects on subsequent stages, whereas under scenario II, a shift in the timing of one stage affects the degree of overlap with previous and subsequent stages. To test this, we combined field manipulations, captivity measurements and geolocation data. We advanced and delayed hatching dates in pied flycatchers (Ficedula hypoleuca) and measured how the timing of subsequent stages (male moult and migration) were affected. There was no causal effect of manipulated hatching dates on the onset of moult and departure to Africa. Thus, advancing hatching dates reduced the male moult-breeding overlap with no effect on the moult-migration interval. Interestingly, the wintering location of delayed males was more westwards, suggesting that delaying the termination of breeding carries over to winter location. Because we found no causal linkage of the timing of annual-cycle stages, climate change could shift these stages at different rates, with the risk that the time available for some becomes so short that this will have major fitness consequences.
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Affiliation(s)
- Barbara M Tomotani
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands .,Museum of New Zealand Te Papa Tongarewa, Wellington 6011, New Zealand
| | - Iván de la Hera
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands.,School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland T23XA50
| | - Cynthia Y M J G Lange
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands
| | - Bart van Lith
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands
| | - Simone L Meddle
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Christiaan Both
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
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15
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Bauer CM, Graham JL, Greives TJ. Corticosterone negative feedback is weaker during spring vs. autumn migration in a songbird (Junco hyemalis). Gen Comp Endocrinol 2019; 280:36-42. [PMID: 30974100 DOI: 10.1016/j.ygcen.2019.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/26/2019] [Accepted: 04/07/2019] [Indexed: 01/31/2023]
Abstract
Birds face many challenges during seasonal migrations and must make important decisions about whether to accelerate, maintain, or delay travel to their final destinations. Spring migration is likely more challenging than autumn migration as spring journeys are completed more quickly and weather conditions are harsher during this time. These differential challenges may be reflected in the endocrine stress response, as the hypothalamic-pituitary-adrenal (HPA) axis is important for both daily energetic needs and coping with stressors. Indeed, most avian studies have found that both baseline and stress-induced corticosterone (CORT) levels tend to be higher in spring migrants than in autumn migrants. We hypothesized that CORT negative feedback efficacy also differs across the season, and is likely weaker during times of year when birds must be most sensitive to stressors. We therefore predicted that CORT negative feedback efficacy would be weaker during spring vs. autumn migration as spring migrants are more likely to encounter situations where they must decide whether to turn back or delay their travel. We examined male dark-eyed juncos (Junco hyemalis) during their spring and autumn stopovers in Fargo, ND, USA. Our prediction was met as we did find that negative feedback efficacy was weaker during spring vs. autumn, although we notably did not find any seasonal differences in baseline and stress-induced CORT. We also found that spring migrants were heavier, had greater subcutaneous fat stores, and had slightly higher hematocrit compared to autumn migrants. These findings suggest that CORT negative feedback sensitivity may help migrating birds effectively cope with the differential challenges of autumn and spring migration.
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Affiliation(s)
- Carolyn M Bauer
- Department of Biology, Adelphi University, Garden City NY, USA.
| | - Jessica L Graham
- Behavioral Ecology, Centre d'Écologie Fonctionnelle et Évolutive, Centre national de la recherche scientifique, 34293 Montpellier, France
| | - Timothy J Greives
- Department of Biological Sciences, North Dakota State University, Fargo ND, USA
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16
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Eikenaar C, Hessler S, Fischer S, Bairlein F. An exception to the rule: Captivity does not stress wild migrating northern wheatears. Gen Comp Endocrinol 2019; 275:25-29. [PMID: 30753841 DOI: 10.1016/j.ygcen.2019.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/05/2019] [Accepted: 02/08/2019] [Indexed: 12/28/2022]
Abstract
Wild animals typically suffer from stress when brought into captivity. This stress is characterized by elevated circulating glucocorticoid levels and weight loss. We here describe for the first time a case where a wild animal, the long-distance migrating northern wheatear, does not show signs of stress when caged. We captured these birds on a stopover site during their spring migration and caged them individually with ad libitum access to food and water. The birds were divided into four groups and were blood-sampled immediately in the field, a few hours after caging, one day after caging, or three days after caging, respectively. From these blood-samples we determined circulating corticosterone level. Food intake and body mass were also monitored. We found that, with very few exceptions, corticosterone levels were low and did not differ among the groups. Accordingly, almost all birds consumed huge quantities of food and substantially increased their body mass. Together these results clearly show that caging does not result in indications of stress in wild migrating northern wheatears. Confinement-specific conditions such as restricted movement normally stress animals. We suggest migratory birds may not perceive such conditions as stressors due to their hyperphagic state, a notion that requires further testing.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Sven Hessler
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Sandra Fischer
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Franz Bairlein
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
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17
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O’Neal BJ, Stafford JD, Larkin RP, Michel ES. The effect of weather on the decision to migrate from stopover sites by autumn-migrating ducks. MOVEMENT ECOLOGY 2018; 6:23. [PMID: 30505448 PMCID: PMC6257954 DOI: 10.1186/s40462-018-0141-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/11/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Previous investigations of autumn-migrating ducks have reported weak connections between weather conditions and the decision to migrate from stopover sites. We leveraged relatively new weather surveillance radar technology to remotely detect departures of discrete groups of various species of migratory dabbling ducks (Anatidae) in autumn to more directly assess the effect of specific weather conditions on departure from discrete stopover sites. METHODS Using radar data collected over fifteen years (1995-2009), we documented a consistent phenomenon where a single, identifiable group departed from our study area on 30% of days during the autumn study period, and no ducks departed on the other days. We gathered weather variables from nearby stations and used them to develop competing models to explain temporal patterns of departure versus non-departure to better understand the potential mechanisms associated with binomial patterns of departures. RESULTS The best approximating model of departure probability was our integrated model, which included variables accounting for wind aloft direction favorable for departure (i.e., tailwind), absence of precipitation, and a partially or completely clear sky. The integrated model accounted for all model weight in the candidate set and explained 55% of the variation in departure probability. Estimated probability of departure was 0.76 after parameterizing the best model with favorable conditions for all covariates. CONCLUSIONS Our results contrasted those of previous studies of autumn duck migration as a small set of simplistic, extrinsic conditions substantially influenced departure decision.
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Affiliation(s)
- Benjamin J. O’Neal
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Champaign, IL USA
- Present address: Franklin College, Franklin, IN USA
| | - Joshua D. Stafford
- Frank C. Bellrose Waterfowl Research Center, Illinois Natural History Survey, Institute of Natural Resource Sustainability, University of Illinois, Havana, IL USA
- Present address: U.S. Geological Survey, South Dakota Cooperative Fish & Wildlife Research Unit, Department of Natural Resource Management, South Dakota State University, Brookings, SD USA
| | - Ronald P. Larkin
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Champaign, IL USA
| | - Eric S. Michel
- Department of Natural Resource Management, South Dakota State University, Brookings, SD USA
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18
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Hegemann A, Alcalde Abril P, Muheim R, Sjöberg S, Alerstam T, Nilsson JÅ, Hasselquist D. Immune function and blood parasite infections impact stopover ecology in passerine birds. Oecologia 2018; 188:1011-1024. [PMID: 30386941 PMCID: PMC6244813 DOI: 10.1007/s00442-018-4291-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022]
Abstract
Stopovers play a crucial role for the success of migrating animals and are key to optimal migration theory. Variation in refuelling rates, stopover duration and departure decisions among individuals has been related to several external factors. The physiological mechanisms shaping stopover ecology are, however, less well understood. Here, we explore how immune function and blood parasite infections relate to several aspects of stopover behaviour in autumn migrating short- and long-distance migrating songbirds. We blood sampled individuals of six species and used an automated radio-telemetry system in the stopover area to subsequently quantify stopover duration, 'bush-level' activity patterns (~ 0.1-30 m), landscape movements (~ 30-6000 m), departure direction and departure time. We show that complement activity, the acute phase protein haptoglobin and blood parasite infections were related to prolonged stopover duration. Complement activity (i.e., lysis) and total immunoglobulins were negatively correlated with bush-level activity patterns. The differences partly depended on whether birds were long-distance or short-distance migrants. Birds infected with avian malaria-like parasites showed longer landscape movements during the stopover than uninfected individuals, and birds with double blood parasite infections departed more than 2.5 h later after sunset/sunrise suggesting shorter flight bouts. We conclude that variation in baseline immune function and blood parasite infection status affects stopover ecology and helps explain individual variation in stopover behaviour. These differences affect overall migration speed, and thus can have significant impact on migration success and induce carry-over effects on other annual-cycle stages. Immune function and blood parasites should, therefore, be considered as important factors when applying optimal migration theory.
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Affiliation(s)
- Arne Hegemann
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden.
| | - Pablo Alcalde Abril
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Rachel Muheim
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Sissel Sjöberg
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden.,Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Thomas Alerstam
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Jan-Åke Nilsson
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Dennis Hasselquist
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
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19
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Eikenaar C, Hessler S, Ballstaedt E, Schmaljohann H, Kaiya H. Ghrelin, corticosterone and the resumption of migration from stopover, an automated telemetry study. Physiol Behav 2018; 194:450-455. [DOI: 10.1016/j.physbeh.2018.06.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/24/2018] [Accepted: 06/25/2018] [Indexed: 01/23/2023]
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20
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Robart AR, McGuire MMK, Watts HE. Increasing photoperiod stimulates the initiation of spring migratory behaviour and physiology in a facultative migrant, the pine siskin. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180876. [PMID: 30225078 PMCID: PMC6124035 DOI: 10.1098/rsos.180876] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 05/04/2023]
Abstract
The transition to a migratory state involves coordinated changes in physiology and behaviour. In species with regular, predictable (obligate) migrations, increasing day length triggers the expression of a spring migratory state and androgens play an important role in stimulating its development. By contrast, we know little about the environmental cues and endocrine mechanisms that regulate migration in species with less predictable (facultative) migrations. Here, we tested whether photoperiod stimulates a migratory state in a facultative nomadic migrant, the pine siskin (Spinus pinus). We exposed wintering birds to either a naturally increasing or short-day photoperiod and measured physiological and behavioural changes indicative of a migratory state. We also examined changes in circulating hormones that may play a role in the migratory transition. Natural-day, but not short-day, birds displayed physiological preparations for migration, including increases in fat deposition, and showed increased levels of migratory restlessness. We found no evidence for a role of corticosterone in the migratory transition, but testosterone may be important. This study is the first experimental test of the role of photoperiod in regulating facultative migration and demonstrates that the predictive cue used by many obligate migrants to time spring migration is also important in a facultative migrant.
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Affiliation(s)
- Ashley R. Robart
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA
- Department of Biology, Loyola Marymount University, Los Angeles, CA 90045, USA
| | - Mali M. K. McGuire
- Department of Biology, Loyola Marymount University, Los Angeles, CA 90045, USA
| | - Heather E. Watts
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA
- Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
- Department of Biology, Loyola Marymount University, Los Angeles, CA 90045, USA
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21
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22
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Eikenaar C, Ballstaedt E, Hessler S, Klinner T, Müller F, Schmaljohann H. Cues, corticosterone and departure decisions in a partial migrant. Gen Comp Endocrinol 2018; 261:59-66. [PMID: 29397064 DOI: 10.1016/j.ygcen.2018.01.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/17/2018] [Accepted: 01/24/2018] [Indexed: 11/20/2022]
Abstract
Most migrating birds make multiple stopovers to fuel and/or rest. The decision to resume migration from stopover is based on various cues, such as time within the season and wind conditions. There are hints that the strength of these departure cues shapes corticosterone level, which in its turn appears to regulate the timing of departure. We here provide results that very strongly indicate that indeed departure cues jointly shape corticosterone level of migrants at stopover. We compared corticosterone level between migrating and sedentary common blackbirds (Turdus merula) sampled simultaneously at the same location during autumn migration. As expected, in migrating individuals corticosterone level was positively associated with time within the season and with current wind conditions. The latter was only apparent in adult birds and not in 1st year migrants, thus matching the observation that 1st year autumnal migrants are less wind selective than adults. In contrast to the migrants, in sedentary blackbirds these "cues" did not explain variation in corticosterone level. Furthermore, stopover departure seemed more likely and to occur earlier in the night in migrants with high corticosterone level. Our unique comparative study thus supports the newly developed concept that corticosterone mediates between departure cues and stopover departure timing in avian migrants.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Elmar Ballstaedt
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Sven Hessler
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Thomas Klinner
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Florian Müller
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Heiko Schmaljohann
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany; Institute for Biology and Environmental Sciences (IBU), Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, D-26129 Oldenburg, Germany
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23
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Eikenaar C, Müller F, Rüppel G, Stöwe M. Endocrine regulation of migratory departure from stopover: Evidence from a longitudinal migratory restlessness study on northern wheatears. Horm Behav 2018; 99:9-13. [PMID: 29408015 DOI: 10.1016/j.yhbeh.2018.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 02/08/2023]
Abstract
Most migrating birds make stopovers to replenish fuel stores. The decision to resume migration from stopover to a large extent shapes the temporal organization of migration. This decision is known to be shaped by a suite of intrinsic and extrinsic factors such as the bird's fuel stores and current weather conditions. However, how departures from stopover are physiologically regulated is largely unknown. We here present data that strongly indicate that corticosterone, a hormone with a stimulatory effect on locomotion, acts as a mediator between fuel stores and departure from stopover. In migrating northern wheatears (Oenanthe oenanthe) temporarily caged at stopover, we observed a positive relationship between the change in fuel stores and the concurrent change in glucocorticoid metabolite (GCM) levels measured in the birds' droppings. We also found a positive relationship between the change in GCM levels and the change in the intensity of nocturnal migratory restlessness. As in northern wheatears nocturnal migratory restlessness is an accurate proxy for stopover departure likelihood, our results indicate that corticosterone mediates between fuel stores and the decision to resume migration. Our unique longitudinal study represents a considerable advance in our understanding of the endocrine regulation of avian migration.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Florian Müller
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Georg Rüppel
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Mareike Stöwe
- Department for Biomedical Sciences, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria
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24
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Loshchagina J, Tsvey A, Naidenko S. Baseline and stress-induced corticosterone levels are higher during spring than autumn migration in European robins. Horm Behav 2018; 98:96-102. [PMID: 29288637 DOI: 10.1016/j.yhbeh.2017.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 12/22/2017] [Accepted: 12/24/2017] [Indexed: 11/21/2022]
Abstract
During spring and autumn migrations, birds undergo a suite of physiological and behavioral adaptations known as migratory disposition. The position of migratory seasons within the annual cycle and specifics of environmental conditions in each season could lead to formation of specific regulatory mechanisms of spring and autumn migratory disposition. However, this topic remains largely unstudied. Here we compared corticosterone (CORT) concentration (baseline and stress-induced) in European robins (Erithacus rubecula) captured during seven consecutive migratory seasons on the Courish Spit in the Baltic Sea; >650 plasma samples were analyzed in total. We found that baseline and stress-induced CORT concentrations in free-living robins during spring migration were nearly twice as high comparing to autumn passage. Moreover, the strength of relationship between these two parameters differed between the seasons. In autumn, individuals with elevated baseline CORT level invariably expressed high stress response; in spring, the stress response was more variable. These facts are in line with the hypothesis that spring and autumn migrations are separate life history stages characterized by similar physiological and behavioral adaptations but somewhat different regulatory mechanisms. Further work is needed to understand effects of seasonal differences in CORT concentrations in regulation of migratory disposition in birds.
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Affiliation(s)
- Julia Loshchagina
- Biological Station Rybachy of the Zoological Institute RAS, Rybachy, Kaliningrad reg. 238535, Russia; Institute of Geography RAS, 29 Staromonetny per., Moscow 119017, Russia
| | - Arseny Tsvey
- Biological Station Rybachy of the Zoological Institute RAS, Rybachy, Kaliningrad reg. 238535, Russia.
| | - Sergey Naidenko
- A.N. Severtsov Institute of Ecology and Evolution RAS, 33 Leninskij ave., Moscow 119071, Russia
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25
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Watts HE, Cornelius JM, Fudickar AM, Pérez J, Ramenofsky M. Understanding variation in migratory movements: A mechanistic approach. Gen Comp Endocrinol 2018; 256:112-122. [PMID: 28756245 DOI: 10.1016/j.ygcen.2017.07.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/20/2017] [Accepted: 07/25/2017] [Indexed: 12/15/2022]
Abstract
Spatial and temporal fluctuations in resource availability have led to the evolution of varied migration patterns. In order to appropriately time movements in relation to resources, environmental cues are used to provide proximate information for timing and the endocrine system serves to integrate these external cues and behavioral and physiological responses. Yet, the regulatory mechanisms underlying migratory timing have rarely been compared across a broad range of migratory patterns. First, we offer an updated nomenclature of migration using a mechanistic perspective to clarify terminology describing migratory types in relation to ecology, behavior and endocrinology. We divide migratory patterns into three types: obligate, nomadic, and fugitive. Obligate migration is characterized by regular and directed annual movements between locations, most commonly for breeding and overwintering, where resources are predictable and sufficient. Nomadic migrations occur less predictably than do obligate migrations as animals make use of potentially rich but ephemeral resources that occur unpredictably in space or time. Fugitive migrations move animals away from an area in response to severe disruption of environmental conditions and occur as part of an emergency life history stage. We also consider partially migratory populations, which include a mix of sedentary and migratory individuals; the movement patterns of partial migrants are expected to fall into one of the three types above. For these various forms of migration, we review our understanding of the environmental cues and endocrine mechanisms that underlie the expression of a migratory state. Several common hormonal mechanisms exist across the varied migratory forms, but there are also important areas where further investigations are needed in order to gain broad insight into the origin of movements and the diversity of migratory patterns. We propose that taking a comparative approach across the migratory types that considers endocrine mechanisms will advance a new understanding of migration biology.
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Affiliation(s)
- Heather E Watts
- Department of Biology, Loyola Marymount University, Los Angeles, CA 90045, USA; School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
| | | | - Adam M Fudickar
- Environmental Resilience Institute, Indiana University, Bloomington, IN 47405, USA
| | - Jonathan Pérez
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, CA 95616, USA
| | - Marilyn Ramenofsky
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, CA 95616, USA
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