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Nespolo RF, Peña I, Mejías C, Ñunque A, Altamirano T, Bozinovic FF. Communal nesting is the optimal strategy for heat conservation in a social marsupial: lessons from biophysical models. J Exp Biol 2022; 225:284634. [PMID: 36420835 PMCID: PMC9720746 DOI: 10.1242/jeb.244606] [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: 06/01/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022]
Abstract
Endothermy, understood as the maintenance of continuous and high body temperatures owing to the combination of metabolic heat production and an insulative cover, is severely challenged in small endotherms inhabiting cold environments. As a response, social clustering combined with nest use (=communal nesting) is a common strategy for heat conservation. To quantify the actual amount of energy that is saved by this strategy, we studied the social marsupial Dromiciops gliroides (monito del monte), an endemic species of the cold forests of southern South America. It is hypothesized that sociability in this marsupial was driven by cold conditions, but evidence supporting this hypothesis is unclear. Here, we used taxidermic models ('mannequins') to experimentally test the energetic benefits of clustering combined with nest use. To do this, we fitted and compared cooling curves of solitary and grouped mannequins, within and outside of a nest, at the typical winter ambient temperatures of their habitat (5°C). We found that the strategy that minimized euthermic cost of maintenance was the combination of nest use and clustering, thus supporting communal nesting as a social adaptation to cope with the cold. Considering the basal metabolic rate of monitos, our estimates suggest that the savings represents almost half of energy consumption per day (in resting conditions). This study shows how simple biophysical models could help to evaluate bioenergetic hypotheses for social behavior in cold-adapted endotherms.
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Affiliation(s)
- Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile,Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile,Millennium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile,Author for correspondence ()
| | - Isabella Peña
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Mejías
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Magister en Ecología Aplicada, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Abel Ñunque
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Millennium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile
| | - Tomás Altamirano
- ECOS (Ecology-Complexity-Society) Laboratory, Center for Local Development (CEDEL), Pontificia Universidad Católica de Chile, Villarrica Campus, La Araucanía Region, Chile,National Audubon Society and Cape Horn International Center for Global Change Studies and Biocultural Conservation, Universidad de Magallanes, Punta Arenas, Chile,Millennium Nucleus Center for the Socioeconomic Impact of Environmental Policies (CESIEP), Chile
| | - Francisco F. Bozinovic
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile,Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Xu JH, Wang Z, Mou JJ, Wang CL, Huang WM, Xue HL, Wu M, Chen L, Xu LX. Up-Regulation of Glycogen Synthesis and Degradation Enzyme Level Maintained Myocardial Glycogen in Huddling Brandt's Voles Under Cool Environments. Front Physiol 2021; 12:593129. [PMID: 33841168 PMCID: PMC8033036 DOI: 10.3389/fphys.2021.593129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 03/04/2021] [Indexed: 11/13/2022] Open
Abstract
Small mammals exhibit limited glucose use and glycogen accumulation during hypothermia. Huddling is a highly evolved cooperative behavioral strategy in social mammals, allowing adaptation to environmental cooling. However, it is not clear whether this behavior affects the utilization of glycogen in cold environments. Here, we studied the effects of huddling on myocardial glycogen content in Brandt’s voles (Lasiopodomys brandtii) under a mild cold environment (15°C). Results showed that (1) Compared to the control (22°C) group (CON), the number of glycogenosomes more than tripled in the cool separated group (CS) in both males and females; whereas the number of glycogenosomes increased in females but was maintained in males in the cool huddling group (CH). (2) Glycogen synthase (GS) activity in the CS group remained unchanged, whereas glycogen phosphorylase (GYPL) activity decreased, which mediated the accumulation of glycogen content of the CS group. (3) Both GS and GYPL activity increased which may contribute to the stability of glycogen content in CH group. (4) The expression levels of glucose transporters GLUT1 and GLUT4 increased in the CS group, accompanied by an increase in glucose metabolism. These results indicate that the reduced glycogen degradation enzyme level and enhanced glucose transport may lead to an increase in myocardial glycogen content of the separated voles under cool environment; while the up-regulation of glycogen synthesis and degradation enzyme level maintained myocardial glycogen content in the huddling vole.
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Affiliation(s)
- Jin-Hui Xu
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Zhe Wang
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Jun-Jie Mou
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Chuan-Li Wang
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Wei-Mei Huang
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Hui-Liang Xue
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Ming Wu
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Lei Chen
- College of Life Sciences, Qufu Normal University, Qufu, China
| | - Lai-Xiang Xu
- College of Life Sciences, Qufu Normal University, Qufu, China
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3
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Wang Z, Xu JH, Mou JJ, Kong XT, Zou JW, Xue HL, Wu M, Xu LX. Novel ultrastructural findings on cardiac mitochondria of huddling Brandt's voles in mild cold environment. Comp Biochem Physiol A Mol Integr Physiol 2020; 249:110766. [DOI: 10.1016/j.cbpa.2020.110766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 10/23/2022]
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Ferretti A, Maggini I, Cardinale M, Fusani L. Heat loss in sleeping garden warblers (Sylvia borin) during migration. J Therm Biol 2020; 94:102772. [PMID: 33293004 DOI: 10.1016/j.jtherbio.2020.102772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 10/06/2020] [Accepted: 10/20/2020] [Indexed: 01/27/2023]
Abstract
For small songbirds, energy is often a limiting factor during migration and, for this reason, they are forced to alternate nocturnal flights with stopovers to rest and replenish energy stores. Stopover duration has a key role for a successful migration and may have an important impact on fitness. Thus, migrants need to optimize their energy consumption at this stage to reduce their permanence at the site. A recent study has shown that lean individuals reduce their metabolic rate when tucking the head in the feathers during sleep. The underlying mechanism is very likely a reduction in conductance, but the thermoregulatory benefit of the increased insulation has never been quantified yet. Here, we compared heat loss in individual migratory birds while sleeping in different postures. Using a thermal camera and a within-individual approach, we estimated that Garden Warblers can reduce their rate of heat loss by 54% by sleeping with the head tucked in the feathers. This energy saving has a relevant impact on the individual's energy balance because it can account for up to 8.69% of daily energy expenditure during stopover. Our study provides novel and important information to understand the fundamental role of thermoregulatory strategies on bird's energy management.
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Affiliation(s)
- Andrea Ferretti
- University of Vienna, Department of Behavioural and Cognitive Biology, Althanstr. 14, 1090 Vienna, Austria; University of Veterinary Medicine, Vienna, Konrad Lorenz Institute of Ethology, Savoyenstr. 1, 1160, Vienna, Austria.
| | - Ivan Maggini
- University of Veterinary Medicine, Vienna, Konrad Lorenz Institute of Ethology, Savoyenstr. 1, 1160, Vienna, Austria.
| | - Massimiliano Cardinale
- Swedish University of Agricultural Sciences, Department of Aquatic Resources, Marine Research Institute, 45330 Lysekil, Sweden.
| | - Leonida Fusani
- University of Vienna, Department of Behavioural and Cognitive Biology, Althanstr. 14, 1090 Vienna, Austria; University of Veterinary Medicine, Vienna, Konrad Lorenz Institute of Ethology, Savoyenstr. 1, 1160, Vienna, Austria.
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5
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Gardner JL, Rowley E, de Rebeira P, de Rebeira A, Brouwer L. Associations between changing climate and body condition over decades in two southern hemisphere passerine birds. ACTA ACUST UNITED AC 2018. [DOI: 10.1186/s40665-018-0038-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Przybylska AS, Boratyński JS, Wojciechowski MS, Jefimow M. Specialist-generalist model of body temperature regulation can be applied at the intraspecific level. ACTA ACUST UNITED AC 2017; 220:2380-2386. [PMID: 28432150 DOI: 10.1242/jeb.160150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 04/12/2017] [Indexed: 11/20/2022]
Abstract
According to theoretical predictions, endothermic homeotherms can be classified as either thermal specialists or thermal generalists. In high cost environments, thermal specialists are supposed to be more prone to using facultative heterothermy than generalists. We tested this hypothesis at the intraspecific level using male laboratory mice (C57BL/cmdb) fasted under different thermal conditions (20 and 10°C) and for different time periods (12-48 h). We predicted that variability of body temperature (Tb) and time spent with Tb below normothermy would increase with the increase of environmental demands (duration of fasting and cold). To verify the above prediction, we measured Tb and energy expenditure of fasted mice. We did not record torpor bouts but we found that variations in Tb and time spent in hypothermia increased with environmental demands. In response to fasting, mice also decreased their energy expenditure. Moreover, animals that showed more precise thermoregulation when fed had more variable Tb when fasted. We postulate that the prediction of the thermoregulatory generalist-specialist trade-off can be applied at the intraspecific level, offering a valid tool for identifying mechanistic explanations of the differences in animal responses to variations in energy supply.
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Affiliation(s)
- Anna S Przybylska
- Department of Animal Physiology, Nicolaus Copernicus University, 87-100 Toruń, Poland
| | - Jan S Boratyński
- Department of Animal Physiology, Nicolaus Copernicus University, 87-100 Toruń, Poland.,Museum and Institute of Zoology, Polish Academy of Sciences, 00-679 Warsaw, Poland
| | | | - Małgorzata Jefimow
- Department of Animal Physiology, Nicolaus Copernicus University, 87-100 Toruń, Poland
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Dantonio V, Batalhão ME, Fernandes MHMR, Komegae EN, Buqui GA, Lopes NP, Gargaglioni LH, Carnio ÉC, Steiner AA, Bícego KC. Nitric oxide and fever: immune-to-brain signaling vs. thermogenesis in chicks. Am J Physiol Regul Integr Comp Physiol 2016; 310:R896-905. [DOI: 10.1152/ajpregu.00453.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/14/2016] [Indexed: 12/18/2022]
Abstract
Nitric oxide (NO) plays a role in thermogenesis but does not mediate immune-to-brain febrigenic signaling in rats. There are suggestions of a different situation in birds, but the underlying evidence is not compelling. The present study was designed to clarify this matter in 5-day-old chicks challenged with a low or high dose of bacterial LPS. The lower LPS dose (2 μg/kg im) induced fever at 3–5 h postinjection, whereas 100 μg/kg im decreased core body temperature (Tc) (at 1 h) followed by fever (at 4 or 5 h). Plasma nitrate levels increased 4 h after LPS injection, but they were not correlated with the magnitude of fever. The NO synthase inhibitor ( NG-nitro-l-arginine methyl ester, l-NAME; 50 mg/kg im) attenuated the fever induced by either dose of LPS and enhanced the magnitude of the Tc reduction induced by the high dose in chicks at 31–32°C. These effects were associated with suppression of metabolic rate, at least in the case of the high LPS dose. Conversely, the effects of l-NAME on Tc disappeared in chicks maintained at 35–36°C, suggesting that febrigenic signaling was essentially unaffected. Accordingly, the LPS-induced rise in the brain level of PGE2 was not affected by l-NAME. Moreover, l-NAME augmented LPS-induced huddling, which is indicative of compensatory mechanisms to run fever in the face of attenuated thermogenesis. Therefore, as in rats, systemic inhibition of NO synthesis attenuates LPS-induced fever in chicks by affecting thermoeffector activity and not by interfering with immune-to-brain signaling. This may constitute a conserved effect of NO in endotherms.
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Affiliation(s)
- Valter Dantonio
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil
- National Institute of Science and Technology-Comparative Physiology (INCT-Fisiologia Comparada), Rio Claro, São Paulo, Brazil
| | - Marcelo E. Batalhão
- Nursing School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Marcia H. M. R. Fernandes
- Department of Animal Science, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil
| | - Evilin N. Komegae
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil; and
| | - Gabriela A. Buqui
- Department of Physics and Chemistry, Núcleo de Pesquisa em Produtos Naturais e Sintéticos, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Norberto P. Lopes
- Department of Physics and Chemistry, Núcleo de Pesquisa em Produtos Naturais e Sintéticos, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luciane H. Gargaglioni
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil
- National Institute of Science and Technology-Comparative Physiology (INCT-Fisiologia Comparada), Rio Claro, São Paulo, Brazil
| | - Évelin C. Carnio
- Nursing School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Alexandre A. Steiner
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil; and
| | - Kênia C. Bícego
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil
- National Institute of Science and Technology-Comparative Physiology (INCT-Fisiologia Comparada), Rio Claro, São Paulo, Brazil
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Nuñez-Villegas M, Bozinovic F, Sabat P. Interplay between group size, huddling behavior and basal metabolism: an experimental approach in the social degu. ACTA ACUST UNITED AC 2013; 217:997-1002. [PMID: 24311802 DOI: 10.1242/jeb.096164] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mammals exposed to low temperatures increase their metabolic rate to maintain constant body temperature and thus compensate for heat loss. This high and costly energetic demand can be mitigated through thermoregulatory behavior such as social grouping or huddling, which helps to decrease metabolic rate as function of the numbers of individuals grouped. Sustained low temperatures in endothermic animals produce changes over time in rates of energy expenditure, by means of phenotypic plasticity. However, the putative modulating effect that huddling exerts on the flexibility of the basal metabolic rate (BMR) due to thermal acclimation remains unknown. We determined BMR values in Octodon degus, an endemic Chilean rodent, after being acclimated to either 15 or 30°C during 60 days, both alone and in groups of three and five individuals. At 15°C, BMR of huddling individuals was 40% lower than that of animals housed alone. Moreover, infrared thermography revealed a significant increase in local surface temperatures in huddled animals. Furthermore, individual thermal conductance was lower in individuals acclimated to 15°C than to 30°C, but no differences were observed between single and grouped animals. Our results indicate that huddling prevents an increase in BMR when animals are acclimated to cold conditions and that this effect is proportional to the number of animals grouped.
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Affiliation(s)
- Monica Nuñez-Villegas
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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Boratyński JS, Rusiński M, Kokurewicz T, Bereszyński A, Wojciechowski MS. Clustering Behavior in Wintering Greater Mouse-Eared BatsMyotis myotis— the Effect of Micro-Environmental Conditions. ACTA CHIROPTEROLOGICA 2012. [DOI: 10.3161/150811012x661738] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Franco M, Contreras C, Cortés P, Chappell MA, Soto-Gamboa M, Nespolo RF. Aerobic power, huddling and the efficiency of torpor in the South American marsupial, Dromiciops gliroides. Biol Open 2012; 1:1178-84. [PMID: 23259051 PMCID: PMC3522878 DOI: 10.1242/bio.20122790] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 08/20/2012] [Indexed: 11/20/2022] Open
Abstract
During periods of cold, small endotherms depend on a continuous supply of food and energy to maintain euthermic body temperature (T(b)), which can be challenging if food is limited. In these conditions, energy-saving strategies are critical to reduce the energetic requirements for survival. Mammals from temperate regions show a wide arrange of such strategies, including torpor and huddling. Here we provide a quantitative description of thermoregulatory capacities and energy-saving strategies in Dromiciops gliroides, a Microbiotherid marsupial inhabiting temperate rain forests. Unlike many mammals from temperate regions, preliminary studies have suggested that this species has low capacity for control and regulation of body temperature, but there is still an incomplete picture of its bioenergetics. In order to more fully understand the physiological capacities of this "living fossil", we measured its scope of aerobic power and the interaction between huddling and torpor. Specifically, we evaluated: (1) the relation between basal (BMR) and maximum metabolic rate (MMR), and (2) the role of huddling on the characteristics of torpor at different temperatures. We found that BMR and MMR were above the expected values for marsupials and the factorial aerobic scope (from [Formula: see text]CO(2)) was 6.0±0.45 (using [Formula: see text]CO(2)) and 6.2±0.23 (using [Formula: see text]O(2)), an unusually low value for mammals. Also, repeatability of physiological variables was non-significant, as in previous studies, suggesting poor time-consistency of energy metabolism. Comparisons of energy expenditure and body temperature (using attached data-loggers) between grouped and isolated individuals showed that at 20°C both average resting metabolic rate and body temperature were higher in groups, essentially because animals remained non-torpid. At 10°C, however, all individuals became torpid and no differences were observed between grouped and isolated individuals. In summary, our study suggests that the main response of Dromiciops gliroides to low ambient temperature is reduced body temperature and torpor, irrespective of huddling. Low aerobic power and low time-consistency of most thermoregulatory traits of Dromiciops gliroides support the idea of poor thermoregulatory abilities in this species.
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Affiliation(s)
- Marcela Franco
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile , Casilla 567, Valdivia , Chile
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Wojciechowski MS, Humphries MM, Careau V, Pinshow B. Introduction to the symposium: environment, energetics, and fitness: a symposium honoring Donald W. Thomas. Integr Comp Biol 2011; 51:333-6. [PMID: 21700570 DOI: 10.1093/icb/icr057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michal S Wojciechowski
- Department of Animal Physiology, Institute of General and Molecular Biology, Nicolaus Copernicus University, ul. Gagarina 9, PL 87-100 Toruń, Poland.
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