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Mazzamuto MV, Morandini M, Lampman W, Wauters LA, Preatoni D, Koprowski JL, Martinoli A. Use of infrared thermography to detect reactions to stressful events: does animal personality matter? Integr Zool 2024; 19:224-239. [PMID: 37248795 DOI: 10.1111/1749-4877.12735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The study of the relationship between animal stress and personality for free-ranging animals is limited and provides contrasting results. The perception of stressors by an individual may vary due to its personality, and certain personality traits may help individuals to better cope with them. Using non-invasive infrared thermography (IRT), we investigated the link between physiological and behavioral components expressed during an acute stress event by free-ranging Fremont's squirrels (Tamiasciurus fremonti). We expected that, during the acute stress event of being approached by the researcher, individuals that showed a fast pace-of-life syndrome (bolder, more active, and less social/more aggressive) based on an arena test would exhibit stronger sympathetic-adrenal-medullary system reactivity showing a more intense stress-induced hyperthermia (high core body temperature and low peripheral temperature) than individuals with a slow pace of life (shy, less active, and more social). We successfully employed IRT technology to images of Fremont's squirrels with identification of the individuals' body parts (eye, nose, ear, hind foot). However, we found no support for our hypothesis. Squirrels' body surface temperatures told us more about a squirrel's external environment and less about the thermal state of the body in that environment following a stressful event. Further studies need to assess how to make IRT effective and efficient in the field and improve its performance in studying the relationships between physiology and personality in wildlife.
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Affiliation(s)
- Maria Vittoria Mazzamuto
- School of Natural Resources and Environment, College of Agriculture and Life Science, University of Arizona, Arizona, USA
- Unità di Analisi e Gestione delle Risorse Ambientali, Dipartimento di Scienze Teoriche e Applicate, Guido Tosi Research Group, Università degli Studi dell'Insubria, Varese, Italy
| | - Marina Morandini
- School of Natural Resources and Environment, College of Agriculture and Life Science, University of Arizona, Arizona, USA
| | - William Lampman
- School of Natural Resources and Environment, College of Agriculture and Life Science, University of Arizona, Arizona, USA
| | - Lucas Armand Wauters
- Unità di Analisi e Gestione delle Risorse Ambientali, Dipartimento di Scienze Teoriche e Applicate, Guido Tosi Research Group, Università degli Studi dell'Insubria, Varese, Italy
| | - Damiano Preatoni
- Unità di Analisi e Gestione delle Risorse Ambientali, Dipartimento di Scienze Teoriche e Applicate, Guido Tosi Research Group, Università degli Studi dell'Insubria, Varese, Italy
| | - John Lad Koprowski
- School of Natural Resources and Environment, College of Agriculture and Life Science, University of Arizona, Arizona, USA
- Haub School of Environment and Natural Resources, University of Wyoming, Wyoming, USA
| | - Adriano Martinoli
- Unità di Analisi e Gestione delle Risorse Ambientali, Dipartimento di Scienze Teoriche e Applicate, Guido Tosi Research Group, Università degli Studi dell'Insubria, Varese, Italy
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2
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Andreasson F, Rostedt E, Nord A. Measuring body temperature in birds - the effects of sensor type and placement on estimated temperature and metabolic rate. J Exp Biol 2023; 226:jeb246321. [PMID: 37969087 PMCID: PMC10753514 DOI: 10.1242/jeb.246321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/08/2023] [Indexed: 11/17/2023]
Abstract
Several methods are routinely used to measure avian body temperature, but different methods vary in invasiveness. This may cause stress-induced increases in temperature and/or metabolic rate and, hence, overestimation of both parameters. Choosing an adequate temperature measurement method is therefore key to accurately characterizing an animal's thermal and metabolic phenotype. Using great tits (Parus major) and four common methods with different levels of invasiveness (intraperitoneal, cloacal, subcutaneous, cutaneous), we evaluated the preciseness of body temperature measurements and effects on resting metabolic rate (RMR) over a 40°C range of ambient temperatures. None of the methods caused overestimation or underestimation of RMR compared with un-instrumented birds, and body or skin temperature estimates did not differ between methods in thermoneutrality. However, skin temperature was lower compared with all other methods below thermoneutrality. These results provide empirical guidance for future research that aims to measure body temperature and metabolic rate in small bird models.
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Affiliation(s)
- Fredrik Andreasson
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Elin Rostedt
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Andreas Nord
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
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3
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Tabh JKR, Hartjes M, Burness G. Endotherms trade body temperature regulation for the stress response. Proc Biol Sci 2023; 290:20231251. [PMID: 37909077 PMCID: PMC10618863 DOI: 10.1098/rspb.2023.1251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 10/06/2023] [Indexed: 11/02/2023] Open
Abstract
Responding to perceived threats is energetically expensive and can require animals to curtail somatic repair, immunity, and even reproduction to balance energy ledgers. In birds and mammals, energetic demands of thermoregulation are often immense, yet whether homeostatic body temperatures are also compromised to aid the stress response is not known. Using data sourced from over 60 years of literature and 24 endotherm species, we show that exposure to non-thermal challenges (e.g. human interaction, social threats) caused body temperatures to decrease in the cold and increase in the warmth, but particularly when species-specific costs of thermoregulation were high and surplus energy low. Biophysical models revealed that allowing body temperature to change in this way liberated up to 24% (mean = 5%) of resting energy expenditure for use towards coping. While useful to avoid energetic overload, these responses nevertheless heighten risks of cold- or heat-induced damage, particularly when coincident with cold- or heatwaves.
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Affiliation(s)
- Joshua K. R. Tabh
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada K9L 0G2
- Department of Biology, Lund University, Lund, 223 62, Sweden
| | - Mariah Hartjes
- 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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Jerem P, Romero LM. It's cool to be stressed: body surface temperatures track sympathetic nervous system activation during acute stress. J Exp Biol 2023; 226:jeb246552. [PMID: 37767773 PMCID: PMC10629684 DOI: 10.1242/jeb.246552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/24/2023] [Indexed: 09/29/2023]
Abstract
The acute stress response can be considered the primary evolutionary adaptation to maximise fitness in the face of unpredictable environmental challenges. However, the difficulties of assessing physiology in natural environments mean that comparatively little is known about how response variation influences fitness in free-living animals. Currently, determining acute stress physiology typically involves blood sampling or cardiac monitoring. Both require trapping and handling, interrupting natural behaviour, and potentially biasing our understanding toward trappable species/individuals. Importantly, limits on repeated sampling also restrict response phenotype characterisation, vital for linking stress with fitness. Surface temperature dynamics resulting from peripheral vasomotor activity during acute stress are increasingly promoted as alternative physiological stress indicators, which can be measured non-invasively using infrared thermal imaging, overcoming many limitations of current methods. Nonetheless, which aspects of stress physiology they represent remains unclear, as the underlying mechanisms are unknown. To date, validations have primarily targeted the hypothalamic-pituitary-adrenal axis, when the sympathetic-adrenal-medullary (SAM) system is likely the primary driver of vasomotor activity during acute stress. To address this deficit, we compared eye and bill region surface temperatures (measured using thermal imaging) with SAM system activity (measured as heart rate variability via electrocardiogram telemetry) in wild-caught captive house sparrows (Passer domesticus) during capture and handling. We found that lower body surface temperatures were associated with increased sympathetic nervous system activation. Consequently, our data confirm that body surface temperatures can act as a proxy for sympathetic activation during acute stress, providing potentially transformative opportunities for linking the acute stress response with fitness in the wild.
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Affiliation(s)
- Paul Jerem
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
- Department of Biology, Tufts University, Medford, MA 02155, USA
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5
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Wongsaengchan C, McCafferty DJ, Lennox K, Nager RG, McKeegan DEF. Non-invasive assessment of positive affective state using infra-red thermography in rats. Anim Welf 2023; 32:e66. [PMID: 38510988 PMCID: PMC10951672 DOI: 10.1017/awf.2023.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 07/27/2023] [Accepted: 08/16/2023] [Indexed: 03/22/2024]
Abstract
With recent increased focus on positive welfare in animal welfare science, there is demand for objective positive welfare indicators. It is unclear whether changes in body surface temperature can be used to non-invasively identify and quantify positive states in mammals. We recorded continuous measurements of tail surface temperature using infra-red thermography (IRT) and concurrent behavioural observations in male and female Wistar rats (Rattus norvegicus). If tail surface temperature can differentiate between positive and negative experiences, we expect a qualitatively different response compared to negative experiences. Three groups of rats were presented with increasing magnitudes of food rewards (neutral/none, one and three rewards). The rats were placed in an arena to which they were habituated and filmed for 30 s before and 30 min after exposure to different rewards. Tail temperature initially decreased from the pre-reward baseline and subsequently returned towards baseline temperature. The overall pattern of the change was the same as for rats subjected to negative stimuli in previous studies. Nevertheless, dynamic changes in tail temperature, specifically the rate of recovery and the behavioural response (exploration), differed between neutral and rewarded rats but failed to distinguish reward magnitude. Sex differences were found in both thermal and behavioural responses, unrelated to reward magnitudes. Female rats exhibited a greater initial response with a slower recovery than male rats, emphasising the value of using of both sexes in animal welfare research. This study improves our understanding of the effects of positive emotions induced by food reward on peripheral body temperature and behaviour.
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Affiliation(s)
- Chanakarn Wongsaengchan
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, GlasgowG12 8QQ, UK
- School of Psychology & Neuroscience, University of St Andrews, St Andrews, KY16 9JP, UK
| | - Dominic J McCafferty
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, GlasgowG12 8QQ, UK
| | - Katie Lennox
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, GlasgowG12 8QQ, UK
| | - Ruedi G Nager
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, GlasgowG12 8QQ, UK
| | - Dorothy EF McKeegan
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, GlasgowG12 8QQ, UK
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Navarrete L, Lübcker N, Alvarez F, Nespolo R, Sanchez-Hernandez JC, Maldonado K, Sharp ZD, Whiteman JP, Newsome SD, Sabat P. A multi-isotope approach reveals seasonal variation in the reliance on marine resources, production of metabolic water, and ingestion of seawater by two species of coastal passerine to maintain water balance. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1120271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Tracing how free-ranging organisms interact with their environment to maintain water balance is a difficult topic to study for logistical and methodological reasons. We use a novel combination of triple-oxygen stable isotope analyses of water extracted from plasma (δ16O, δ17O, δ18O) and bulk tissue carbon (δ13C) and nitrogen (δ15N) isotopes of feathers and blood to estimate the proportional contribution of marine resources, seawater, and metabolic water used by two species of unique songbirds (genus Cinclodes) to maintain their water balance in a seasonal coastal environment. We also assessed the physiological adjustments that these birds use to maintain their water balance. In agreement with previous work on these species, δ13C and δ15N data show that the coastal resident and invertivore C. nigrofumosus consumes a diet rich in marine resources, while the diet of migratory C. oustaleti shifts seasonally between marine (winter) to freshwater aquatic resources (summer). Triple-oxygen isotope analysis (Δ17O) of blood plasma, basal metabolic rate (BMR), and total evaporative water loss (TEWL) revealed that ~25% of the body water pool of both species originated from metabolic water, while the rest originated from a mix of seawater and fresh water. Δ17O measurements suggest that the contribution of metabolic water tends to increase in summer in C. nigrofumosus, which is coupled with a significant increase in BMR and TEWL. The two species had similar BMR and TEWL during the austral winter when they occur sympatrically in coastal environments. We also found a positive and significant association between the use of marine resources as measured by δ13C and δ15N values and the estimated δ18O values of ingested (pre-formed) water in both species, which indicates that Cinclodes do not directly drink seawater but rather passively ingest when consuming marine invertebrates. Finally, results obtained from physiological parameters and the isotope-based estimates of marine (food and water) resource use are consistent, supporting the use of the triple-oxygen isotopes to quantify the contribution of water sources to the total water balance of free-ranging birds.
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Eye Region Surface Temperature and Corticosterone Response to Acute Stress in a High-Arctic Seabird, the Little Auk. Animals (Basel) 2022; 12:ani12040499. [PMID: 35203208 PMCID: PMC8868316 DOI: 10.3390/ani12040499] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/31/2022] [Accepted: 02/12/2022] [Indexed: 02/05/2023] Open
Abstract
Measuring changes in surface body temperature (specifically in eye-region) in vertebrates using infrared thermography is increasingly applied for detection of the stress reaction. Here we investigated the relationship between the eye-region temperature (TEYE; measured with infrared thermography), the corticosterone level in blood (CORT; stress indicator in birds), and some covariates (ambient temperature, humidity, and sex/body size) in a High-Arctic seabird, the Little Auk Alle alle. The birds responded to the capture-restrain protocol (blood sampling at the moment of capturing, and after 30 min of restrain) by a significant TEYE and CORT increase. However, the strength of the TEYE and CORT response to acute stress were not correlated. It confirms the results of a recent study on other species and all together indicates that infrared thermography is a useful, non-invasive measure of hypothalamic-pituitary-adrenal (HPA) axis reactivity under acute activation, but it might not be a suitable proxy for natural variation of circulating glucocorticoid levels.
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8
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Tabh JKR, Mastromonaco GF, Burness G. Stress-induced changes in body surface temperature are repeatable, but do not differ between urban and rural birds. Oecologia 2022; 198:663-677. [PMID: 35138449 DOI: 10.1007/s00442-022-05120-z] [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: 03/23/2021] [Accepted: 01/18/2022] [Indexed: 11/29/2022]
Abstract
Urbanisation can alter local microclimates, thus creating new thermal challenges for resident species. However, urban environments also present residents with frequent, novel stressors (e.g., noise, human interaction) which may demand investment in costly, self-preserving responses (e.g., the fight-or-flight response). One way that urban residents might cope with this combination of demands is by using regional heterothermy to reduce costs of thermoregulation during the stress response. In this study, we used black-capped chickadees (nurban = 9; nrural = 10) to test whether known heterothermic responses to stress exposure (here, at the bare skin around the eye): (1) varied consistently among individuals (i.e., were repeatable), and (2) were most pronounced among urban individuals compared with rural individuals. Further, to gather evidence for selection on stress-induced heterothermic responses in urban settings, we tested: (3) whether repeatability of this response was lower among birds sampled from urban environments compared with those sampled from rural environments. For the first time, we show that heterothermic responses to stress exposures (i.e. changes in body surface temperature) were highly repeatable across chronic time periods (R = 0.58) but not acute time periods (R = 0.13). However, we also show that these responses did not differ between urban and rural birds, nor were our repeatability estimates any lower in our urban sample. Thus, while regional heterothermy during stress exposure may provide energetic benefits to some, but not all, individuals, enhanced use of this response to cope with urban pressures appears unlikely in our study species.
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Affiliation(s)
- Joshua K R Tabh
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, K9L 0G2, Canada. .,Department of Wildlife and Science, Toronto Zoo, Scarborough, ON, M1B 5K7, Canada.
| | | | - Gary Burness
- Department of Biology, Trent University, Peterborough, ON, K9L 0G2, Canada
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9
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Czenze ZJ, Freeman MT, Kemp R, van Jaarsveld B, Wolf BO, McKechnie AE. Efficient Evaporative Cooling and Pronounced Heat Tolerance in an Eagle-Owl, a Thick-Knee and a Sandgrouse. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.799302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Avian evaporative cooling and the maintenance of body temperature (Tb) below lethal limits during heat exposure has received more attention in small species compared to larger-bodied taxa. Here, we examined thermoregulation at air temperatures (Tair) approaching and exceeding normothermic Tb in three larger birds that use gular flutter, thought to provide the basis for pronounced evaporative cooling capacity and heat tolerance. We quantified Tb, evaporative water loss (EWL) and resting metabolic rate (RMR) in the ∼170-g Namaqua sandgrouse (Pterocles namaqua), ∼430-g spotted thick-knee (Burhinus capensis) and ∼670-g spotted eagle-owl (Bubo africanus), using flow-through respirometry and a stepped Tair profile with very low chamber humidities. All three species tolerated Tair of 56–60°C before the onset of severe hyperthermia, with maximum Tb of 43.2°C, 44.3°C, and 44.2°C in sandgrouse, thick-knees and eagle-owls, respectively. Evaporative scope (i.e., maximum EWL/minimum thermoneutral EWL) was 7.4 in sandgrouse, 12.9 in thick-knees and 7.8 in eagle-owls. The relationship between RMR and Tair varied substantially among species: whereas thick-knees and eagle-owls showed clear upper critical limits of thermoneutrality above which RMR increased rapidly and linearly, sandgrouse did not. Maximum evaporative heat loss/metabolic heat production ranged from 2.8 (eagle-owls) to 5.5 (sandgrouse), the latter the highest avian value yet reported. Our data reveal some larger species with gular flutter possess pronounced evaporative cooling capacity and heat tolerance and, when taken together with published data, show thermoregulatory performance varies widely among species larger than 250 g. Our data for Namaqua sandgrouse reveal unexpectedly pronounced variation in the metabolic costs of evaporative cooling within the genus Pterocles.
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10
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Appenroth D, Nord A, Hazlerigg DG, Wagner GC. Body Temperature and Activity Rhythms Under Different Photoperiods in High Arctic Svalbard ptarmigan ( Lagopus muta hyperborea). Front Physiol 2021; 12:633866. [PMID: 33762966 PMCID: PMC7982588 DOI: 10.3389/fphys.2021.633866] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/15/2021] [Indexed: 01/11/2023] Open
Abstract
Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (T b) alongside locomotor activity in captive birds under different photoperiods. We show that T b and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in T b attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in T b preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.
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Affiliation(s)
- Daniel Appenroth
- Arctic Chronobiology and Physiology, Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Andreas Nord
- Arctic Chronobiology and Physiology, Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.,Section for Evolutionary Ecology, Department of Biology, Lund University, Lund, Sweden
| | - David G Hazlerigg
- Arctic Chronobiology and Physiology, Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Gabriela C Wagner
- Arctic Chronobiology and Physiology, Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Forest and Forest Resources, Norwegian Institute of Bioeconomy Research (NIBIO), Tromsø, Norway
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11
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Robertson JK, Mastromonaco GF, Burness G. Social hierarchy reveals thermoregulatory trade-offs in response to repeated stressors. J Exp Biol 2020; 223:jeb229047. [PMID: 32967999 DOI: 10.1242/jeb.229047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/09/2020] [Indexed: 11/20/2022]
Abstract
Coping with stressors can require substantial energetic investment, and when resources are limited, such investment can preclude simultaneous expenditure on other biological processes. Among endotherms, energetic demands of thermoregulation can also be immense, yet our understanding of whether a stress response is sufficient to induce changes in thermoregulatory investment is limited. Using the black-capped chickadee as a model species, we tested a hypothesis that stress-induced changes in surface temperature (Ts), a well-documented phenomenon across vertebrates, stem from trade-offs between thermoregulation and stress responsiveness. Because social subordination is known to constrain access to resources in this species, we predicted that Ts and dry heat loss of social subordinates, but not social dominants, would fall under stress exposure at low ambient temperatures (Ta), and rise under stress exposure at high Ta, thus permitting a reduction in total energetic expenditure toward thermoregulation. To test our predictions, we exposed four social groups of chickadees to repeated stressors and control conditions across a Ta gradient (n=30 days/treatment/group), whilst remotely monitoring social interactions and Ts Supporting our hypothesis, we show that: (1) social subordinates (n=12), who fed less than social dominants and alone experienced stress-induced mass-loss, displayed significantly larger changes in Ts following stress exposure than social dominants (n=8), and (2) stress-induced changes in Ts significantly increased heat conservation at low Ta and heat dissipation at high Ta among social subordinates alone. These results suggest that chickadees adjust their thermoregulatory strategies during stress exposure when resources are limited by ecologically relevant processes.
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Affiliation(s)
- Joshua K Robertson
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada K9L 0G2
- Department of Wildlife and Science, Toronto Zoo, Scarborough, ON, Canada M1B 5K7
| | | | - Gary Burness
- Department of Biology, Trent University, Peterborough, ON, Canada K9L 0G2
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12
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Lewden A, Nord A, Bonnet B, Chauvet F, Ancel A, McCafferty DJ. Body surface rewarming in fully and partially hypothermic king penguins. J Comp Physiol B 2020; 190:597-609. [PMID: 32656594 PMCID: PMC7441059 DOI: 10.1007/s00360-020-01294-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 06/11/2020] [Accepted: 06/25/2020] [Indexed: 11/29/2022]
Abstract
Penguins face a major thermal transition when returning to land in a hypothermic state after a foraging trip. Uninsulated appendages (flippers and feet) could provide flexible heat exchange during subsequent rewarming. Here, we tested the hypothesis that peripheral vasodilation could be delayed during this recovery stage. To this end, we designed an experiment to examine patterns of surface rewarming in fully hypothermic (the cloaca and peripheral regions (here; flippers, feet and the breast) < 37 °C) and partially hypothermic (cloaca at normothermia ≥ 37 °C, but periphery at hypothermia) king penguins (Aptenodytes patagonicus) when they rewarmed in the laboratory. Both groups rewarmed during the 21 min observation period, but the temperature changes were larger in fully than in partially hypothermic birds. Moreover, we observed a 5 min delay of peripheral temperature in fully compared to partially hypothermic birds, suggesting that this process was impacted by low internal temperature. To investigate whether our laboratory data were applicable to field conditions, we also recorded surface temperatures of free-ranging penguins after they came ashore to the colony. Initial surface temperatures were lower in these birds compared to in those that rewarmed in the laboratory, and changed less over a comparable period of time on land. This could be explained both by environmental conditions and possible handling-induced thermogenesis in the laboratory. Nevertheless, this study demonstrated that appendage vasodilation is flexibly used during rewarming and that recovery may be influenced by both internal temperature and environmental conditions when penguins transition from sea to land.
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Affiliation(s)
- Agnès Lewden
- Département Ecologie, Université de Strasbourg, CNRS, Physiologie et Ethologie, IPHC UMR 7178, 67000, Strasbourg, France. .,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Andreas Nord
- Department of Biology, Section for Evolutionary Ecology, Lund University, 223 62, Lund, Sweden.,Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan, Glasgow, G63 0AW, Scotland, UK
| | - Batshéva Bonnet
- Centre D'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360, Villiers en Bois, France
| | - Florent Chauvet
- Centre D'Etudes Biologiques de Chizé, CNRS, UMR 7372, 79360, Villiers en Bois, France
| | - André Ancel
- Département Ecologie, Université de Strasbourg, CNRS, Physiologie et Ethologie, IPHC UMR 7178, 67000, Strasbourg, France
| | - Dominic J McCafferty
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan, Glasgow, G63 0AW, Scotland, UK
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13
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Faraji J, Metz GAS. Infrared Thermography Reveals Sex-Specific Responses to Stress in Mice. Front Behav Neurosci 2020; 14:79. [PMID: 32523518 PMCID: PMC7261839 DOI: 10.3389/fnbeh.2020.00079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/28/2020] [Indexed: 01/20/2023] Open
Abstract
Psychogenic hyperthermia is a stress-related condition reported mostly in women. Neuroendocrine responses to stress in females differ from those in males, and these differences cannot be explained solely based on hypothalamic-pituitary-adrenal (HPA) axis activity. Here, we used infrared (IR) thermographic imaging to record changes in cutaneous temperature following two types of stressful experiences in female and male mice. Mice were exposed to either single-session restraint stress or vertical exploration (rearing) deprivation and were monitored for exploratory activity and IR surface thermal changes. Females displayed higher rearing activity than males during the dark phase of the light cycle. Both sexes showed similar plasma corticosterone (CORT) responses after a challenge with restraint and rearing deprivation. However, only females responded to rearing deprivation with increased cutaneous temperature in the head and back, and a reduced thermal response in the tail. Circulating CORT levels were not correlated with the thermal variations. These findings, for the first time, provide evidence for sex-specific cutaneous thermal responses to short-term stress in mice following transient vertical-activity deprivation that may mimic clinical psychogenic hyperthermia.
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Affiliation(s)
- Jamshid Faraji
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.,Faculty of Nursing & Midwifery, Golestan University of Medical Sciences, Gorgan, Iran
| | - Gerlinde A S Metz
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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14
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Nord A, Hegemann A, Folkow LP. Reduced immune responsiveness contributes to winter energy conservation in an Arctic bird. J Exp Biol 2020; 223:223/8/jeb219287. [DOI: 10.1242/jeb.219287] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/11/2020] [Indexed: 12/20/2022]
Abstract
ABSTRACT
Animals in seasonal environments must prudently manage energy expenditure to survive the winter. This may be achieved through reductions in the allocation of energy for various purposes (e.g. thermoregulation, locomotion, etc.). We studied whether such trade-offs also include suppression of the innate immune response, by subjecting captive male Svalbard ptarmigan (Lagopus muta hyperborea) to bacterial lipopolysaccharide (LPS) during exposure to either mild temperature (0°C) or cold snaps (acute exposure to −20°C), in constant winter darkness when birds were in energy-conserving mode, and in constant daylight in spring. The innate immune response was mostly unaffected by temperature. However, energy expenditure was below baseline when birds were immune challenged in winter, but significantly above baseline in spring. This suggests that the energetic component of the innate immune response was reduced in winter, possibly contributing to energy conservation. Immunological parameters decreased (agglutination, lysis, bacteriostatic capacity) or did not change (haptoglobin/PIT54) after the challenge, and behavioural modifications (anorexia, mass loss) were lengthy (9 days). While we did not study the mechanisms explaining these weak, or slow, responses, it is tempting to speculate they may reflect the consequences of having evolved in an environment where pathogen transmission rate is presumably low for most of the year. This is an important consideration if climate change and increased exploitation of the Arctic would alter pathogen communities at a pace outwith counter-adaption in wildlife.
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Affiliation(s)
- Andreas Nord
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
- Department of Arctic and Marine Biology, University of Tromsø – the Arctic University of Norway, NO-9037 Tromsø, Norway
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Rowardennan G63 0AW, UK
| | - Arne Hegemann
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
| | - Lars P. Folkow
- Department of Arctic and Marine Biology, University of Tromsø – the Arctic University of Norway, NO-9037 Tromsø, Norway
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15
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Winder LA, White SA, Nord A, Helm B, McCafferty DJ. Body surface temperature responses to food restriction in wild and captive great tits. ACTA ACUST UNITED AC 2020; 223:223/8/jeb220046. [PMID: 32312718 DOI: 10.1242/jeb.220046] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/27/2020] [Indexed: 12/21/2022]
Abstract
During winter at temperate and high latitudes, the low ambient temperatures, limited food supplies and short foraging periods mean small passerines show behavioural, morphological and physiological adaptations to reduce the risk of facing energy shortages. Peripheral tissues vasoconstrict in low ambient temperatures to reduce heat loss and cold injury. Peripheral vasoconstriction has been observed with food restriction in captivity but has yet to be explored in free-ranging animals. We experimentally food restricted both wild and captive great tits (Parus major) during winter months and measured surface temperatures of the bill and eye region using thermal imaging, to investigate whether birds show rapid local heterothermic responses, which may reduce their thermoregulatory costs when facing a perceived imminent food shortage. Our results of a continuously filmed wild population showed that bill temperature was immediately reduced in response to food restriction compared with when food was available ad libitum, an apparent autonomic response. Such immediacy implies a 'pre-emptive' response before the bird experiences any shortfalls in energy reserves. We also demonstrate temporal variation in vasoconstriction of the bill, with bill temperature gradually rising throughout the food restriction after the initial drop. Eye-region temperature in the wild birds remained at similar levels throughout food restriction compared with unrestricted birds, possibly reflecting the need to maintain steady circulation to the central nervous and visual systems. Our findings provide evidence that birds selectively allow the bill to cool when a predictable food supply is suddenly disrupted, probably as a means of minimising depletion of body reserves for a perceived future shortage in energy.
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Affiliation(s)
- Lucy A Winder
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan G63 0AW, UK .,Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Stewart A White
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan G63 0AW, UK
| | - Andreas Nord
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan G63 0AW, UK.,Department of Biology, Section for Evolutionary Ecology, Lund University, SE-223 62 Lund, Sweden
| | - Barbara Helm
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan G63 0AW, UK.,Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, 9747 AG Groningen, The Netherlands
| | - Dominic J McCafferty
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Rowardennan G63 0AW, UK
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16
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Robertson JK, Mastromonaco G, Burness G. Evidence that stress-induced changes in surface temperature serve a thermoregulatory function. J Exp Biol 2020; 223:jeb213421. [PMID: 31974220 DOI: 10.1242/jeb.213421] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/20/2020] [Indexed: 08/26/2023]
Abstract
The fact that body temperature can rise or fall following exposure to stressors has been known for nearly two millennia; however, the functional value of this phenomenon remains poorly understood. We tested two competing hypotheses to explain stress-induced changes in temperature, with respect to surface tissues. Under the first hypothesis, changes in surface temperature are a consequence of vasoconstriction that occur to attenuate blood loss in the event of injury and serve no functional purpose per se; defined as the 'haemoprotective hypothesis'. Under the second hypothesis, changes in surface temperature reduce thermoregulatory burdens experienced during activation of a stress response, and thus hold a direct functional value: the 'thermoprotective hypothesis'. To understand whether stress-induced changes in surface temperature have functional consequences, we tested predictions of these two hypotheses by exposing black-capped chickadees (n=20) to rotating stressors across an ecologically relevant ambient temperature gradient, while non-invasively monitoring surface temperature (eye region temperature) using infrared thermography. Our results show that individuals exposed to rotating stressors reduce surface temperature and dry heat loss at low ambient temperature and increase surface temperature and dry heat loss at high ambient temperature, when compared with controls. These results support the thermoprotective hypothesis and suggest that changes in surface temperature following stress exposure have functional consequences and are consistent with an adaptation. Such findings emphasize the importance of the thermal environment in shaping physiological responses to stressors in vertebrates, and in doing so, raise questions about their suitability within the context of a changing climate.
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Affiliation(s)
- Joshua K Robertson
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada, K9L 0G2
- Department of Reproductive Physiology, The Toronto Zoo, Scarborough, Ontario, Canada, M1B 5K7
| | - Gabriela Mastromonaco
- Department of Reproductive Physiology, The Toronto Zoo, Scarborough, Ontario, Canada, M1B 5K7
| | - Gary Burness
- Department of Biology, Trent University, Peterborough, Ontario, Canada, K9L 0G2
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