101
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Tissier ML, Réale D, Garant D, Bergeron P. Consumption of red maple in anticipation of beech mast‐seeding drives reproduction in eastern chipmunks. J Anim Ecol 2020; 89:1190-1201. [DOI: 10.1111/1365-2656.13183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/08/2019] [Indexed: 11/29/2022]
Affiliation(s)
| | - Denis Réale
- Département des Sciences Biologiques Université du Québec à Montréal Montréal QC Canada
| | - Dany Garant
- Département de Biologie Université de Sherbrooke Sherbrooke QC Canada
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102
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Geary B, Leberg PL, Purcell KM, Walter ST, Karubian J. Breeding Brown Pelicans Improve Foraging Performance as Energetic Needs Rise. Sci Rep 2020; 10:1686. [PMID: 32015412 PMCID: PMC6997155 DOI: 10.1038/s41598-020-58528-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 01/10/2020] [Indexed: 11/09/2022] Open
Abstract
Optimal foraging theory states that animals should maximize resource acquisition rates with respect to energy expenditure, which may involve alteration of strategies in response to changes in resource availability and energetic need. However, field-based studies of changes in foraging behavior at fine spatial and temporal scales are rare, particularly among species that feed on highly mobile prey across broad landscapes. To derive information on changes in foraging behavior of breeding brown pelicans (Pelecanus occidentalis) over time, we used GPS telemetry and distribution models of their dominant prey species to relate bird movements to changes in foraging habitat quality in the northern Gulf of Mexico. Over the course of each breeding season, pelican cohorts began by foraging in suboptimal habitats relative to the availability of high-quality patches, but exhibited a marked increase in foraging habitat quality over time that outpaced overall habitat improvement trends across the study site. These findings, which are consistent with adjustment of foraging patch use in response to increased energetic need, highlight the degree to which animal populations can optimize their foraging behaviors in the context of uncertain and dynamic resource availability, and provide an improved understanding of how landscape-level features can impact behavior.
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Affiliation(s)
- Brock Geary
- Department of Ecology and Evolutionary Biology, Tulane University, 6823 Saint Charles Avenue, 400 Lindy Boggs Center, New Orleans, LA, 70118, USA. .,Department of Biology, University of Louisiana at Lafayette, 410 East St. Mary Boulevard, 108 Billeaud Hall, Lafayette, LA, 70503, USA.
| | - Paul L Leberg
- Department of Biology, University of Louisiana at Lafayette, 410 East St. Mary Boulevard, 108 Billeaud Hall, Lafayette, LA, 70503, USA
| | - Kevin M Purcell
- National Marine Fisheries Service, Southeast Fisheries Science Center, Beaufort Laboratory, Beaufort, NC, USA.,Data Science and Analytics Group, Harrisburg University of Science and Technology, 326 Market St, Harrisburg, PA, USA
| | - Scott T Walter
- Department of Ecology and Evolutionary Biology, Tulane University, 6823 Saint Charles Avenue, 400 Lindy Boggs Center, New Orleans, LA, 70118, USA.,Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - Jordan Karubian
- Department of Ecology and Evolutionary Biology, Tulane University, 6823 Saint Charles Avenue, 400 Lindy Boggs Center, New Orleans, LA, 70118, USA
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103
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Affiliation(s)
- Justin G. Boyles
- Cooperative Wildlife Research Laboratory Center for Ecology, and School of Biological Sciences Southern Illinois University Carbondale IL USA
| | | | - Anna Blomberg
- Department of Biology University of Turku Vesilinnantie 520100Turku Finland
| | - Thomas M. Lilley
- Finnish Museum of Natural History University of Helsinki P. Rautatiekatu 1300100Helsinki Finland
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104
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Poo S, Hinkson KM, Stege E. Sperm output and body condition are maintained independently of hibernation in an endangered temperate amphibian. Reprod Fertil Dev 2019; 31:796-804. [PMID: 30514432 DOI: 10.1071/rd18073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 11/13/2018] [Indexed: 11/23/2022] Open
Abstract
Hibernation is an integral part of the life history of species living in seasonal environments. However, our knowledge about the link between hibernation and reproductive success in amphibians remains limited, which poses an obstacle for critical conservation efforts. To fill this gap, we quantified the effects of captive hibernation on sperm quality, sperm quantity and body condition in an endangered anuran, the Wyoming toad (Anaxyrus baxteri), and used naturally hibernated wild toads as a standard for comparison. We hypothesised that hibernation is essential for optimal sperm output but is detrimental to body condition. Sperm collection was performed using assisted reproductive technologies for both captive and wild toads. Contrary to our hypotheses, no differences were observed in sperm metrics (total number of cells, concentration, motility and viability) or in body condition across captive treatment groups (0, 30 or 60 days of hibernation). Moreover, no difference was found between sperm metrics of captive toads and wild toads. These unexpected findings suggest that hibernation may not be an essential process for spermiation in A. baxteri while using exogenous hormones, and illustrate the potential of temperate amphibians to adapt to varying environmental conditions during winter months.
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Affiliation(s)
- Sinlan Poo
- Department of Research and Conservation, Memphis Zoo, 2000 Prentiss Place, Memphis, TN 38112, USA
| | - Kristin M Hinkson
- Department of Research and Conservation, Memphis Zoo, 2000 Prentiss Place, Memphis, TN 38112, USA
| | - Edward Stege
- US Fish and Wildlife Services, Leadville National Fish Hatchery, 2846 Highway 300, Leadville, CO 80461, USA
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105
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Ryan CC, Burns LE, Broders HG. Changes in underground roosting patterns to optimize energy conservation in hibernating bats. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0340] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Non-migratory bats in colder climates use hibernation to survive winter. By reducing metabolic rate (i.e., using torpor), bats can survive winter on stored fat reserves. During hibernation, bats arouse from torpor and may move within the hibernaculum, a process called “internal migration”. We hypothesized that internal migration occurs to optimize hibernation energetics in that bats move to select a microclimate to minimize energy expenditure both by seeking cooler areas of the hibernacula and avoiding those with large temperature fluctuations. Early in the winter, we observed that 62% of bats were roosting in the warmer, less energy efficient, deepest 50% of an abandoned mine hibernaculum. Late in the season, there was a shift towards the cooler entrance area, thereby decreasing energy demands during the torpid period, with 78% of bats in the mine roosting within 50 m of the entrance. Although there was no significant effect of hibernation period (i.e., early vs. late winter) on the number of bats in huddles, the largest huddles occurred close to the entrance in late winter. To fully understand and manage bat populations, it is important to understand that hibernation is a dynamic process with bats moving and interacting with one another throughout the season.
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Affiliation(s)
- Caleb C. Ryan
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Lynne E. Burns
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4J1, Canada
| | - Hugh G. Broders
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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106
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Nowack J, Tarmann I, Hoelzl F, Smith S, Giroud S, Ruf T. Always a price to pay: hibernation at low temperatures comes with a trade-off between energy savings and telomere damage. Biol Lett 2019; 15:20190466. [PMID: 31573426 PMCID: PMC6832184 DOI: 10.1098/rsbl.2019.0466] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We suggest that the high-energy demand of frequent arousals is counteracted by a lower temperature differential between torpid and euthermic body temperature and that telomere length is restored during arousals when the body temperature is returned to normothermic values. Taken together, our study shows that hibernation at low body temperatures comes with costs on a cellular level and that hibernators need to actively counterbalance the shortening of telomeres.
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Affiliation(s)
- Julia Nowack
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Iris Tarmann
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Franz Hoelzl
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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107
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Lemieux V, Garant D, Reale D, Bergeron P. Spatio-temporal variation in oxidative status regulation in a small mammal. PeerJ 2019; 7:e7801. [PMID: 31608176 PMCID: PMC6788435 DOI: 10.7717/peerj.7801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/31/2019] [Indexed: 11/23/2022] Open
Abstract
Life-history allocation trade-offs are dynamic over time and space according to the ecological and demographical context. Fluctuations in food availability can affect physiological trade-offs like oxidative status regulation, reflecting the balance between pro-oxidant production and antioxidant capacity. Monitoring the spatio-temporal stability of oxidative status in natural settings may help understanding its importance in ecological and evolutionary processes. However, few studies have yet conducted such procedures in wild populations. Here, we monitored individual oxidative status in a wild eastern chipmunk (Tamias striatus) population across the 2017 summer active period and over three study sites. Oxidative damage (MDA: Malondialdehyde levels) and non-enzymatic antioxidant levels (FRAP: Ferric reducing antioxidant power and HASC: Hypochlorous acid shock capacity) were quantified across time and space using assays optimized for small blood volumes. Our results showed an increase in oxidative damage mirrored by a decrease in FRAP throughout the season. We also found different antioxidant levels among our three study sites for both markers. Our results also revealed the effects of sex and body mass on oxidative status. Early in the active season, females and individuals with a greater body mass had higher oxidative damage. Males had higher HASC levels than females throughout the summer. This study shows that oxidative status regulation is a dynamic process that requires a detailed spatial and temporal monitoring to yield a complete picture of possible trade-offs between pro-oxidant production and antioxidant capacity.
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Affiliation(s)
- Vincent Lemieux
- Départment de biologie, Université de Sherbrooke, Sherbrooke, Canada
- Biological Sciences, Bishop’s University, Sherbrooke, Canada
| | - Dany Garant
- Départment de biologie, Université de Sherbrooke, Sherbrooke, Canada
| | - Denis Reale
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Canada
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108
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Fowler NL, Belant JL, Wang G, Leopold BD. Ecological plasticity of denning chronology by American black bears and brown bears. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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109
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Chazarin B, Ziemianin A, Evans AL, Meugnier E, Loizon E, Chery I, Arnemo JM, Swenson JE, Gauquelin-Koch G, Simon C, Blanc S, Lefai E, Bertile F. Limited Oxidative Stress Favors Resistance to Skeletal Muscle Atrophy in Hibernating Brown Bears ( Ursus Arctos). Antioxidants (Basel) 2019; 8:antiox8090334. [PMID: 31443506 PMCID: PMC6770786 DOI: 10.3390/antiox8090334] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/18/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
Oxidative stress, which is believed to promote muscle atrophy, has been reported to occur in a few hibernators. However, hibernating bears exhibit efficient energy savings and muscle protein sparing, despite long-term physical inactivity and fasting. We hypothesized that the regulation of the oxidant/antioxidant balance and oxidative stress could favor skeletal muscle maintenance in hibernating brown bears. We showed that increased expressions of cold-inducible proteins CIRBP and RBM3 could favor muscle mass maintenance and alleviate oxidative stress during hibernation. Downregulation of the subunits of the mitochondrial electron transfer chain complexes I, II, and III, and antioxidant enzymes, possibly due to the reduced mitochondrial content, indicated a possible reduction of the production of reactive oxygen species in the hibernating muscle. Concomitantly, the upregulation of cytosolic antioxidant systems, under the control of the transcription factor NRF2, and the maintenance of the GSH/GSSG ratio suggested that bear skeletal muscle is not under a significant oxidative insult during hibernation. Accordingly, lower levels of oxidative damage were recorded in hibernating bear skeletal muscles. These results identify mechanisms by which limited oxidative stress may underlie the resistance to skeletal muscle atrophy in hibernating brown bears. They may constitute therapeutic targets for the treatment of human muscle atrophy.
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Affiliation(s)
- Blandine Chazarin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
- Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Anna Ziemianin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
- Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Alina L Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
| | - Emmanuelle Meugnier
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Emmanuelle Loizon
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Isabelle Chery
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
| | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
| | | | - Chantal Simon
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Stéphane Blanc
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
| | - Etienne Lefai
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
- Université d'Auvergne, INRA, UNH UMR1019, F-63122 Saint-Genès Champanelle, France
| | - Fabrice Bertile
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France.
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110
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Meierhofer MB, Johnson JS, Leivers SJ, Pierce BL, Evans JE, Morrison ML. Winter habitats of bats in Texas. PLoS One 2019; 14:e0220839. [PMID: 31393965 PMCID: PMC6687166 DOI: 10.1371/journal.pone.0220839] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/25/2019] [Indexed: 12/28/2022] Open
Abstract
Few studies have described winter microclimate selection by bats in the southern United States. This is of particular importance as the cold-adapted fungus, Pseudogymnoascus destructans, which causes the fatal bat disease white-nose syndrome (WNS), continues to spread into southern United States. To better understand the suitability of winter bat habitats for the growth of P. destructans in this region, we collected roost temperature and vapor pressure deficit from 97 hibernacula in six ecoregions in Texas during winter 2016-17 and 2017-18. We also measured skin temperature of Rafinesque's big-eared bats (Corynorhinus townsendii), Townsend's big-eared bats (C. townsendii), big-brown bats (Eptesicus fuscus), southeastern myotis (Myotis austroriparius), cave myotis (M. velifer), tri-colored bats (Perimyotis subflavus), and Mexican free-tailed bats (Tadarida brasiliensis) during hibernation to study their use of torpor in these habitats. We found that temperatures within hibernacula were strongly correlated with external air temperatures and were often within the optimal range of temperatures for P. destructans growth. Hibernacula and skin temperatures differed among species, with Rafinesque's big-eared bats, southeastern myotis, and Mexican free-tailed bats occupying warmer microclimates and having higher torpid skin temperatures. For species that were broadly distributed throughout Texas, hibernacula and skin temperatures differed within species by ecoregion; Tri-colored bats and cave myotis in colder, northern regions occupied colder microclimates within hibernacula and exhibited colder skin temperatures, than individuals of the same species in warmer, southern regions. These data illustrate the variability in microclimates used as hibernacula by bats in Texas and suggest similar variation in susceptibility to WNS in the state. Thus, monitoring microclimates at winter roosts may help predict where WNS may develop, and where management efforts would be most effective.
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Affiliation(s)
- Melissa B. Meierhofer
- Department of Wildlife and Fisheries Sciences, Texas A&M University, Texas, United States of America
- Natural Resources Institute, Texas A&M University, Texas, United States of America
| | - Joseph S. Johnson
- Department of Biological Sciences, Ohio University, Athens, Ohio, United States of America
| | - Samantha J. Leivers
- Natural Resources Institute, Texas A&M University, Texas, United States of America
| | - Brian L. Pierce
- Natural Resources Institute, Texas A&M University, Texas, United States of America
| | - Jonah E. Evans
- Wildlife Diversity Program, Texas Parks and Wildlife Department, Boerne, Texas, United States of America
| | - Michael L. Morrison
- Department of Wildlife and Fisheries Sciences, Texas A&M University, Texas, United States of America
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111
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Transient drug-tolerance and permanent drug-resistance rely on the trehalose-catalytic shift in Mycobacterium tuberculosis. Nat Commun 2019; 10:2928. [PMID: 31266959 PMCID: PMC6606615 DOI: 10.1038/s41467-019-10975-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/12/2019] [Indexed: 12/21/2022] Open
Abstract
Stochastic formation of Mycobacterium tuberculosis (Mtb) persisters achieves a high level of antibiotic-tolerance and serves as a source of multidrug-resistant (MDR) mutations. As conventional treatment is not effective against infections by persisters and MDR-Mtb, novel therapeutics are needed. Several approaches were proposed to kill persisters by altering their metabolism, obviating the need to target active processes. Here, we adapted a biofilm culture to model Mtb persister-like bacilli (PLB) and demonstrated that PLB underwent trehalose metabolism remodeling. PLB use trehalose as an internal carbon to biosynthesize central carbon metabolism intermediates instead of cell surface glycolipids, thus maintaining levels of ATP and antioxidants. Similar changes were identified in Mtb following antibiotic-treatment, and MDR-Mtb as mechanisms to circumvent antibiotic effects. This suggests that trehalose metabolism is associated not only with transient drug-tolerance but also permanent drug-resistance, and serves as a source of adjunctive therapeutic options, potentiating antibiotic efficacy by interfering with adaptive strategies. Trehalose metabolism has been linked to Mycobacterium tuberculosis (Mtb) virulence and biofilm formation. Here, using a model of drug-tolerant persisters and metabolomics, the authors dissect the role of trehalose metabolism in Mtb persister formation, linking trehalose-catalytic shift to antibiotic resistance.
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112
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Chazarin B, Storey KB, Ziemianin A, Chanon S, Plumel M, Chery I, Durand C, Evans AL, Arnemo JM, Zedrosser A, Swenson JE, Gauquelin-Koch G, Simon C, Blanc S, Lefai E, Bertile F. Metabolic reprogramming involving glycolysis in the hibernating brown bear skeletal muscle. Front Zool 2019; 16:12. [PMID: 31080489 PMCID: PMC6503430 DOI: 10.1186/s12983-019-0312-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Background In mammals, the hibernating state is characterized by biochemical adjustments, which include metabolic rate depression and a shift in the primary fuel oxidized from carbohydrates to lipids. A number of studies of hibernating species report an upregulation of the levels and/or activity of lipid oxidizing enzymes in muscles during torpor, with a concomitant downregulation for glycolytic enzymes. However, other studies provide contrasting data about the regulation of fuel utilization in skeletal muscles during hibernation. Bears hibernate with only moderate hypothermia but with a drop in metabolic rate down to ~ 25% of basal metabolism. To gain insights into how fuel metabolism is regulated in hibernating bear skeletal muscles, we examined the vastus lateralis proteome and other changes elicited in brown bears during hibernation. Results We show that bear muscle metabolic reorganization is in line with a suppression of ATP turnover. Regulation of muscle enzyme expression and activity, as well as of circulating metabolite profiles, highlighted a preference for lipid substrates during hibernation, although the data suggested that muscular lipid oxidation levels decreased due to metabolic rate depression. Our data also supported maintenance of muscle glycolysis that could be fuelled from liver gluconeogenesis and mobilization of muscle glycogen stores. During hibernation, our data also suggest that carbohydrate metabolism in bear muscle, as well as protein sparing, could be controlled, in part, by actions of n-3 polyunsaturated fatty acids like docosahexaenoic acid. Conclusions Our work shows that molecular mechanisms in hibernating bear skeletal muscle, which appear consistent with a hypometabolic state, likely contribute to energy and protein savings. Maintenance of glycolysis could help to sustain muscle functionality for situations such as an unexpected exit from hibernation that would require a rapid increase in ATP production for muscle contraction. The molecular data we report here for skeletal muscles of bears hibernating at near normal body temperature represent a signature of muscle preservation despite atrophying conditions.
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Affiliation(s)
- Blandine Chazarin
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France.,10Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Kenneth B Storey
- 2Department of Biology, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - Anna Ziemianin
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France.,10Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Stéphanie Chanon
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Marine Plumel
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Isabelle Chery
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Christine Durand
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Alina L Evans
- 4Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
| | - Jon M Arnemo
- 4Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway.,5Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Andreas Zedrosser
- 6Department of Environmental and Health Studies, University College of Southeast Norway, N-3800 Bø, Telemark Norway.,7Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, A-1180 Vienna, Austria
| | - Jon E Swenson
- 8Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway.,9Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
| | | | - Chantal Simon
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Stephane Blanc
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Etienne Lefai
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France.,Université d'Auvergne, INRA, UNH UMR1019, F-63122 Saint-Genès Champanelle, France
| | - Fabrice Bertile
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
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113
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Gantchoff MG, Beyer D, Belant JL. Reproductive class influences risk tolerance during denning and spring for American black bears (
Ursus americanus
). Ecosphere 2019. [DOI: 10.1002/ecs2.2705] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- M. G. Gantchoff
- Camp Fire Program in Wildlife Conservation College of Environmental Science and Forestry State University of New York New York New York 13210 USA
| | - D. Beyer
- Wildlife Division Michigan DNR Marquette Michigan 49855 USA
| | - J. L. Belant
- Camp Fire Program in Wildlife Conservation College of Environmental Science and Forestry State University of New York New York New York 13210 USA
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114
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115
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Hertel AG, Zedrosser A, Kindberg J, Langvall O, Swenson JE. Fluctuating mast production does not drive Scandinavian brown bear behavior. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21619] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anne G. Hertel
- Norwegian University of Life SciencesFaculty of Environmental Sciences and Natural Resource ManagementNO‐1430 ÅsNorway
| | - Andreas Zedrosser
- University of Southeast NorwayDepartment of Natural Sciences and Environmental HealthNO‐3800 BøNorway
| | - Jonas Kindberg
- Norwegian Institute for Nature ResearchNO‐7485 Trondheim and Department of Fish, Wildlife and Environmental StudiesSwedish University of Agricultural SciencesUmeåSweden
| | - Ola Langvall
- Swedish University of Agricultural SciencesSE‐75007 UppsalaSweden
| | - Jon E. Swenson
- Norwegian University of Life SciencesFaculty of Environmental Sciences and Natural Resource ManagementNO‐1430 ÅsNorway
- Norway and Norwegian Institute for Nature ResearchNO‐7485 TrondheimNorway
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116
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Tuzovic S, Kabadayi S. The influence of social distancing on employee well-being: a conceptual framework and research agenda. JOURNAL OF SERVICE MANAGEMENT 2018. [DOI: 10.1108/josm-05-2020-0140] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PurposeThe ongoing pandemic caused by the coronavirus disease 2019 (COVID-19) virus has severely influenced lives and livelihoods. As service organizations either face hibernation or continuity of their business operations, the impact of social distancing measures raises major concerns for the well-being of service employees. In this paper, the authors develop a conceptual framework to examine how different social distancing practices impact an organization's service continuity or service hibernation, which in turn affects different dimensions of their employee subjective well-being during the COVID-19 pandemic.Design/methodology/approachThe authors draw on macroeconomic data and industrial reports, linking them to theoretical concepts to develop a conceptual framework and a research agenda to serve as a starting point to fully understand the impact of this pandemic on employee well-being.FindingsThis article develops an overarching framework and research agenda to investigate the impact of social distancing practices on employee well-being.Originality/valueThe authors propose two opposing business concepts – service continuity and service hibernation – as possible responses to social distancing measures. By bridging different theoretical domains, the authors suggeste that there is a need to holistically examine macro-, meso- and micro-level factors to fully understand the impact of social distancing–related measures on employee well-being.
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117
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Yuan S, Fu H, Wu X, Yang S, Malqin X, Yue X. Effects of grazing on the northern three-toed jerboa pre- and post-hibernation. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shuai Yuan
- College of Grassland; Resources and Environment; Inner Mongolia Agricultural University; 29 Erdos East Street, Saihan District Hohhot Inner Mongolia 010011 P. R. China
| | - Heping Fu
- College of Grassland; Resources and Environment; Inner Mongolia Agricultural University; 29 Erdos East Street, Saihan District Hohhot Inner Mongolia 010011 P. R. China
| | - Xiaodong Wu
- College of Grassland; Resources and Environment; Inner Mongolia Agricultural University; 29 Erdos East Street, Saihan District Hohhot Inner Mongolia 010011 P. R. China
| | - Suwen Yang
- College of Grassland; Resources and Environment; Inner Mongolia Agricultural University; 29 Erdos East Street, Saihan District Hohhot Inner Mongolia 010011 P. R. China
| | - Xingan Malqin
- College of Grassland; Resources and Environment; Inner Mongolia Agricultural University; 29 Erdos East Street, Saihan District Hohhot Inner Mongolia 010011 P. R. China
| | - Xiuxian Yue
- Institute of Forestry Monitoring and Planning of Inner Mongolia Autonomous Region; Hohhot 010020 P. R. China
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118
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Mandic M, Regan MD. Can variation among hypoxic environments explain why different fish species use different hypoxic survival strategies? ACTA ACUST UNITED AC 2018; 221:221/21/jeb161349. [PMID: 30381477 DOI: 10.1242/jeb.161349] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In aquatic environments, hypoxia is a multi-dimensional stressor that can vary in O2 level (partial pressure of O2 in water, PwO2 ), rate of induction and duration. Natural hypoxic environments can therefore be very different from one another. For the many fish species that have evolved to cope with these different hypoxic environments, survival requires adjusting energy supply and demand pathways to maintain energy balance. The literature describes innumerable ways that fishes combine aerobic metabolism, anaerobic metabolism and metabolic rate depression (MRD) to accomplish this, but it is unknown whether the evolutionary paths leading to these different strategies are determined primarily by species' phylogenetic histories, genetic constraint or their native hypoxic environments. We explored this idea by devising a four-quadrant matrix that bins different aquatic hypoxic environments according to their duration and PwO2 characteristics. We then systematically mined the literature for well-studied species native to environments within each quadrant, and, for each of 10 case studies, described the species' total hypoxic response (THR), defined as its hypoxia-induced combination of sustained aerobic metabolism, enhanced anaerobic metabolism and MRD, encompassing also the mechanisms underlying these metabolic modes. Our analysis revealed that fishes use a wide range of THRs, but that distantly related species from environments within the same matrix quadrant have converged on similar THRs. For example, environments of moderately hypoxic PwO2 favoured predominantly aerobic THRs, whereas environments of severely hypoxic PwO2 favoured MRD. Capacity for aerial emergence as well as predation pressure (aquatic and aerial) also contributed to these responses, in addition to other biotic and abiotic factors. Generally, it appears that the particular type of hypoxia experienced by a fish plays a major role in shaping its particular THR.
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Affiliation(s)
- Milica Mandic
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 6N5
| | - Matthew D Regan
- Comparative Biosciences Department, University of Wisconsin-Madison, Madison, WI 35706, USA
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119
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Le Coeur C, Pisanu B, Chapuis JL, Robert A. Within- and between-year variations of reproductive strategy and cost in a population of Siberian chipmunks. Oecologia 2018; 188:765-776. [PMID: 30219947 DOI: 10.1007/s00442-018-4259-3] [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: 11/20/2017] [Accepted: 09/10/2018] [Indexed: 10/28/2022]
Abstract
Reproduction costs depend on the general life-history strategies employed by organisms for resource acquisition, the decision rules on resource allocation, and the resource availability. Although the predictability of resource availability is expected to influence the breeding strategy, the relationship between predictability and strategy has rarely been investigated at the population level. One reason is that, while the resource availability is commonly variable in space and time, their predictability is generally assumed constant. Here, we addressed the temporal variation of the breeding strategy and its associated survival cost in a hibernating population of Tamias sibiricus, in which food resources vary in their availability between years and in their predictability within years. Based on 11 years of mark-recapture data, we used multi-event modelling to investigate seasonal variations in reproduction costs of female chipmunks that breed twice a year (spring and summer). In summer, during which a large variety and quantity of resources is available (income breeding strategy), the proportion of breeding females was consistent across years and reproduction yielded no mortality cost. In contrast, in spring, the proportion of breeding females was positively correlated with the amount of resources available for hibernation (partial capital breeding strategy). Spring reproduction yielded no immediate cost, but induced a delayed mortality cost over the next winter if future unknown conditions were unfavorable. Our findings highlight complex temporal reproductive patterns in a short-lived species: not only does the modality of resource acquisition vary among seasons, but also the decision rule to breed and its associated cost.
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Affiliation(s)
- Christie Le Coeur
- Centre d'Ecologie et des Sciences de la Conservation (CESCO), Muséum national d'Histoire naturelle, Centre National de la Recherche Scientifique, Sorbonne-Université, 61 rue Buffon, 75005, Paris, France.
| | - Benoît Pisanu
- Centre d'Ecologie et des Sciences de la Conservation (CESCO), Muséum national d'Histoire naturelle, Centre National de la Recherche Scientifique, Sorbonne-Université, 61 rue Buffon, 75005, Paris, France
| | - Jean-Louis Chapuis
- Centre d'Ecologie et des Sciences de la Conservation (CESCO), Muséum national d'Histoire naturelle, Centre National de la Recherche Scientifique, Sorbonne-Université, 61 rue Buffon, 75005, Paris, France
| | - Alexandre Robert
- Centre d'Ecologie et des Sciences de la Conservation (CESCO), Muséum national d'Histoire naturelle, Centre National de la Recherche Scientifique, Sorbonne-Université, 61 rue Buffon, 75005, Paris, France
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120
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Bieber C, Turbill C, Ruf T. Effects of aging on timing of hibernation and reproduction. Sci Rep 2018; 8:13881. [PMID: 30224823 PMCID: PMC6141465 DOI: 10.1038/s41598-018-32311-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/28/2018] [Indexed: 01/17/2023] Open
Abstract
Small hibernators are long-lived for their size because seasonal dormancy greatly reduces predation risk. Thus, within a year, hibernators switch between states of contrasting mortality risk (active season versus hibernation), making them interesting species for testing the predictions of life-history theory. Accordingly, we hypothesized that, with advancing age and hence diminishing reproductive potential, hibernators should increasingly accept the higher predation risk associated with activity to increase the likelihood of current reproductive success. For edible dormice (Glis glis) we show that age strongly affects hibernation/activity patterns, and that this occurs via two pathways: (i) with increasing age, dormice are more likely to reproduce, which delays the onset of hibernation, and (ii) age directly advances emergence from hibernation in spring. We conclude that hibernation has to be viewed not merely as an energy saving strategy under harsh climatic conditions, but as an age-affected life-history trait that is flexibly used to maximize fitness.
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Affiliation(s)
- Claudia Bieber
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstraße 1, 1160, Vienna, Austria.
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - Christopher Turbill
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstraße 1, 1160, Vienna, Austria
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121
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Speers-Roesch B, Norin T, Driedzic WR. The benefit of being still: energy savings during winter dormancy in fish come from inactivity and the cold, not from metabolic rate depression. Proc Biol Sci 2018; 285:20181593. [PMID: 30185640 PMCID: PMC6158517 DOI: 10.1098/rspb.2018.1593] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/13/2018] [Indexed: 12/26/2022] Open
Abstract
Winter dormancy is used by many animals to survive the cold and food-poor high-latitude winter. Metabolic rate depression, an active downregulation of resting cellular energy turnover and thus standard (resting) metabolic rate (SMR), is a unifying strategy underlying the persistence of organisms in such energy-limited environments, including hibernating endotherms. However, controversy exists about its involvement in winter-dormant aquatic ectotherms. To address this debate, we conducted simultaneous, multi-day measurements of whole-animal oxygen consumption rate (a proxy of metabolic rate) and spontaneous movement in a model winter-dormant marine fish, the cunner (Tautogolabrus adspersus). Winter dormancy in cunner involved a dampened diel rhythm of metabolic rate, such that a low and stable metabolic rate persisted throughout the 24 h day. Based on the thermal sensitivity (Q10) of SMR as well as correlations of metabolic rate and movement, the reductions in metabolic rate were not attributable to metabolic rate depression, but rather to reduced activity under the cold and darkness typical of the winter refuge among substrate. Previous reports of metabolic rate depression in cunner, and possibly other fish species, during winter dormancy were probably confounded by variation in activity. Unlike hibernating endotherms, and excepting the few fish species that overwinter in anoxic waters, winter dormancy in fishes, as exemplified by cunner, need not involve metabolic rate depression. Rather, energy savings come from inactivity combined with passive physico-chemical effects of the cold on SMR, demonstrating that thermal effects on activity can greatly influence temperature-metabolism relationships, and illustrating the benefit of simply being still in energy-limited environments.
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Affiliation(s)
- Ben Speers-Roesch
- Department of Ocean Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada A1C 5S7
| | - Tommy Norin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - William R Driedzic
- Department of Ocean Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada A1C 5S7
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122
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Gene expression profiling during hibernation in the European hamster. Sci Rep 2018; 8:13167. [PMID: 30177816 PMCID: PMC6120936 DOI: 10.1038/s41598-018-31506-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 08/21/2018] [Indexed: 12/14/2022] Open
Abstract
Hibernation is an exceptional physiological response to a hostile environment, characterized by a seasonal period of torpor cycles involving dramatic reductions of body temperature and metabolism, and arousal back to normothermia. As the mechanisms regulating hibernation are still poorly understood, here we analysed the expression of genes involved in energy homeostasis, torpor regulation, and daily or seasonal timing using digital droplet PCR in various central and peripheral tissues sampled at different stages of torpor/arousal cycles in the European hamster. During torpor, the hypothalamus exhibited strongly down-regulated gene expression, suggesting that hypothalamic functions were reduced during this period of low metabolic activity. During both torpor and arousal, many structures (notably the brown adipose tissue) exhibited altered expression of deiodinases, potentially leading to reduced tissular triiodothyronine availability. During the arousal phase, all analysed tissues showed increased expression of the core clock genes Per1 and Per2. Overall, our data indicated that the hypothalamus and brown adipose tissue were the tissues most affected during the torpor/arousal cycle, and that clock genes may play critical roles in resetting the body’s clocks at the beginning of the active period.
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123
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Siutz C, Valent M, Ammann V, Niebauer A, Millesi E. Sex-specific effects of food supplementation on hibernation performance and reproductive timing in free-ranging common hamsters. Sci Rep 2018; 8:13082. [PMID: 30166598 PMCID: PMC6117252 DOI: 10.1038/s41598-018-31520-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/20/2018] [Indexed: 02/03/2023] Open
Abstract
Hibernation is characterized by reduced metabolism and body temperature during torpor bouts. Energy reserves available during winter play an important role for hibernation and some species respond to high energy reserves with reduced torpor expression. Common hamsters are food-storing hibernators and females hibernate for shorter periods than males, probably related to larger food stores. In this study, we provided free-ranging common hamsters with sunflower seeds shortly before winter and recorded body temperature using subcutaneously implanted data loggers. We compared hibernation patterns and body mass changes between individuals with and without food supplements and analysed reproductive onset in females. Supplemented males delayed hibernation onset, hibernated for much shorter periods, and emerged in spring with higher body mass than unsupplemented ones. Additional food did not affect hibernation performance in females, but supplemented females emerged earlier and preceded those without food supplements in reproductive onset. Thus, males and females differently responded to food supplementation: access to energy-rich food stores enabled males to shorten the hibernation period and emerge in better body condition, probably enhancing mating opportunities and reproductive success. Females did not alter hibernation patterns, but started to reproduce earlier than unsupplemented individuals, enabling reproductive benefits by an extended breeding period.
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Affiliation(s)
- Carina Siutz
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
| | - Margit Valent
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Viktoria Ammann
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Ariane Niebauer
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
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124
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Reher S, Ehlers J, Rabarison H, Dausmann KH. Short and hyperthermic torpor responses in the Malagasy bat Macronycteris commersoni reveal a broader hypometabolic scope in heterotherms. J Comp Physiol B 2018; 188:1015-1027. [PMID: 30121696 DOI: 10.1007/s00360-018-1171-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 06/23/2018] [Accepted: 07/05/2018] [Indexed: 11/28/2022]
Abstract
The energy budgets of animal species are closely linked to their ecology, and balancing energy expenditure with energy acquisition is key for survival. Changes in animals' environments can be challenging, particularly for bats, which are small endotherms with large uninsulated flight membranes. Heterothermy is a powerful response used to cope with changing environmental conditions. Recent research has revealed that many tropical and subtropical species are heterothermic and display torpor with patterns unlike those of "classical" heterotherms from temperate and arctic regions. However, only a handful of studies investigating torpor in bats in their natural environment exist. Therefore, we investigated whether the Malagasy bat Macronycteris commersoni enters torpor in the driest and least predictable region in Madagascar. We examined the energy balance and thermal biology of M. commersoni in the field by relating metabolic rate (MR) and skin temperature (Tskin) measurements to local environmental characteristics in the dry and rainy seasons. Macronycteris commersoni entered torpor and showed extreme variability in torpor patterns, including surprisingly short torpor bouts, lasting on average 20 min, interrupted by MR peaks. Torpid MR was remarkably low (0.13 ml O2 h-1 g-1), even when Tskin exceeded that of normothermia (41 °C). Macronycteris commersoni is thus physiologically capable of (1) entering torpor at high ambient temperature and Tskin and (2) rapidly alternating between torpid and normothermic MR resulting in very short bouts. This suggests that the scope of hypometabolism amongst heterothermic animals is broader than previously assumed and underlines the importance of further investigation into the torpor continuum.
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Affiliation(s)
- Stephanie Reher
- Functional Ecology, Institute for Zoology, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany.
| | - Julian Ehlers
- Animal Ecology and Conservation, Institute for Zoology, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
| | - Hajatiana Rabarison
- Mention Zoologie et Biodiversité Animale, Faculté des Sciences, Université d'Antananarivo, BP 906, Antananarivo 101, Madagascar
| | - Kathrin H Dausmann
- Functional Ecology, Institute for Zoology, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
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125
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Field KA, Sewall BJ, Prokkola JM, Turner GG, Gagnon MF, Lilley TM, Paul White J, Johnson JS, Hauer CL, Reeder DM. Effect of torpor on host transcriptomic responses to a fungal pathogen in hibernating bats. Mol Ecol 2018; 27:3727-3743. [PMID: 30080945 DOI: 10.1111/mec.14827] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 07/25/2018] [Accepted: 07/28/2018] [Indexed: 01/07/2023]
Abstract
Hibernation, the use of prolonged torpor to depress metabolism, is employed by mammals to conserve resources during extended periods of extreme temperatures and/or resource limitation. Mammalian hibernators arouse to euthermy periodically during torpor for reasons that are not well understood, and these arousals may facilitate immune processes. To determine whether arousals enable host responses to pathogens, we used dual RNA-Seq and a paired sampling approach to examine gene expression in a hibernating bat, the little brown myotis (Myotis lucifugus). During torpor, transcript levels differed in only a few genes between uninfected wing tissue and adjacent tissue infected with Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome. Within 70-80 min after emergence from torpor, large changes in gene expression were observed due to local infection, particularly in genes involved in pro-inflammatory host responses to fungal pathogens, but also in many genes involved in immune responses and metabolism. These results support the hypothesis that torpor is a period of relative immune dormancy and arousals allow for local immune responses in infected tissues during hibernation. Host-pathogen interactions were also found to regulate gene expression in the pathogen differently depending on the torpor state of the host. Hibernating species must balance the benefits of energy and water conservation achieved during torpor with the costs of decreased immune competence. Interbout arousals allow hibernators to optimize these, and other, trade-offs during prolonged hibernation by enabling host responses to pathogens within brief, periodic episodes of euthermy.
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Affiliation(s)
- Kenneth A Field
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - Brent J Sewall
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Jenni M Prokkola
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - Gregory G Turner
- Wildlife Diversity Division, Pennsylvania Game Commission, Harrisburg, Pennsylvania
| | - Marianne F Gagnon
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Thomas M Lilley
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - J Paul White
- Wisconsin Department of Natural Resources, Madison, Wisconsin
| | - Joseph S Johnson
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | | | - DeeAnn M Reeder
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
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Weitten M, Tissier ML, Robin JP, Habold C. Dietary proteins improve hibernation and subsequent reproduction in the European hamster, Cricetus cricetus. Am J Physiol Regul Integr Comp Physiol 2018; 315:R848-R855. [PMID: 30024776 DOI: 10.1152/ajpregu.00146.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The reproductive success of hibernators depends not only on food quality during reproduction but also on their body condition when emerging after hibernation, which, in turn, is highly dependent on the hibernation pattern. To date, no studies, to our knowledge, have fully investigated the role of macronutrients throughout the annual lifecycle of hibernators and the strong interdependency between its different phases. This study tested the effects of two diets with different lipid and protein composition on the prehibernation body condition, hibernation pattern, and reproduction of captive-reared European hamsters. Hamsters fed the high-lipid diet gained more body mass in the prehibernation period than those eating the high-protein diet, spent less time in torpor, and thus lost more body mass during hibernation. Despite similar body conditions in both groups at the start of reproduction, the group fed the high-protein diet had higher reproductive success, with more numerous and larger pups than in the high-lipid group. This study reveals that the macronutrient content of diets affects the different phases of the annual lifecycle in hamsters, each of which affects the next. Thus, a high-lipid diet induces less torpor use during hibernation because of a better prehibernation body condition and negatively impacts subsequent reproduction.
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Affiliation(s)
- Mathieu Weitten
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Unité Mixte de Recherche 7178, Strasbourg , France
| | - Mathilde Louise Tissier
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Unité Mixte de Recherche 7178, Strasbourg , France
| | - Jean-Patrice Robin
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Unité Mixte de Recherche 7178, Strasbourg , France
| | - Caroline Habold
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Unité Mixte de Recherche 7178, Strasbourg , France
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127
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Mulawa EA, Kirkwood JS, Wolfe LM, Wojda SJ, Prenni JE, Florant GL, Donahue SW. Seasonal Changes in Endocannabinoid Concentrations between Active and Hibernating Marmots (Marmota flaviventris). J Biol Rhythms 2018; 33:388-401. [DOI: 10.1177/0748730418777660] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hibernation is a naturally occurring model for studying diseases such as obesity and osteoporosis. Hibernators, marmots (Marmota flaviventris) among them, are able to nearly double their body mass by increasing fat stores prior to hibernation without the negative consequences of obesity. They are also physically inactive for extended periods of time without experiencing negative effects on the skeleton. The endocannabinoid system is involved in modulating neural signaling, circannual rhythms, behavior, appetite, thermogenesis, and bone and energy metabolism. These systems are also altered to maintain homeostasis during hibernation. This study aims to better understand the involvement of the endocannabinoid system in the regulation of physiological processes during hibernation by quantifying the seasonal variation of endocannabinoids and endocannabinoid-like ligands in both active and hibernating marmots. We hypothesized that there would be significant changes in endocannabinoid concentrations at the tissue level in marmots between active and hibernating states. Concentrations were measured in brain, serum, brown adipose tissue, white adipose tissue, bone marrow, cortical bone, and trabecular bone using microflow chromatography coupled with tandem quadrupole mass spectrometry. Significant changes were found, such as a 30-fold decrease in 2-arachidonoyl glycerol (2-AG) in cortical bone during hibernation. Many endocannabinoid and endocannabinoid-like ligands decreased in brown adipose tissue, white adipose tissue, and cortical bone, while several ligands increased in bone marrow. This result supports our hypothesis and suggests the possibility of a peripherally controlled shift in energy metabolism, reduction in bone metabolism, and suppression of the immune system during hibernation.
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128
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Sprenger RJ, Tanumihardjo SA, Kurtz CC. Developing a Model of Vitamin A Deficiency in a Hibernating Mammal, the 13-Lined Ground Squirrel ( Ictidomys tridecemlineatus). Comp Med 2018; 68:196-203. [PMID: 29801522 DOI: 10.30802/aalas-cm-17-000113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Retinoic acid, a bioactive metabolite of vitamin A, plays key roles in immune function and vision and adipose tissue development. Our goal was to study the effect of vitamin A deficiency in physiologic changes seen in hibernating 13-lined ground squirrels (Ictidomys tridecemlineatus). In this study, we first developed a model of vitamin A deficiency that was based on published mouse models; we then examined the role of RA in the circannual cycle of and adipose accumulation in this hibernating species. Gravid female ground squirrels began consuming a deficient diet during the last 2 wk of their 4-wk gestation; pups received the diet until they were 8 wk old, when severe symptoms of hypovitaminosis were observed, requiring the animals' removal from the protocol. Body size and adipose mass were significantly lower in vitamin-deficient pups than controls. To avoid these complications, we developed a second model, in which pups started on the deficient diet after weaning. The revised model produced few symptoms of deficiency, and squirrels were able to remain on the diet through spring emergence. Liver retinol analysis showed that deficient squirrels essentially had no vitamin A stores. Our data suggest that 13-lined ground squirrels maintain higher concentrations of stored retinol than other rodent species, such that their dietary needs may differ from those of traditional laboratory rodent models. Our results indicate that ground squirrels are especially susceptible to vitamin A deficiency, and ground squirrels should not be fed a deficient diet until after weaning, to avoid severe symptoms. Interestingly, vitamin A deficiency does not seem to affect this species' ability to hibernate successfully.
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Affiliation(s)
- Ryan J Sprenger
- Department of Biology, University of Wisconsin-Oshkosh, Oshkosh, Wisconsin, USA
| | | | - Courtney C Kurtz
- Department of Biology, University of Wisconsin-Oshkosh, Oshkosh, Wisconsin, USA.
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129
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BATS RECOVERING FROM WHITE-NOSE SYNDROME ELEVATE METABOLIC RATE DURING WING HEALING IN SPRING. J Wildl Dis 2018; 54:480-490. [PMID: 29617187 DOI: 10.7589/2017-08-195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Host responses to infection with novel pathogens are costly and require trade-offs among physiologic systems. One such pathogen is the fungus Pseudogymnoascus destructans (Pd) that causes white-nose syndrome (WNS) and has led to mass mortality of hibernating bats in eastern North America. Although infection with Pd does not always result in death, we hypothesized that bats that survive infection suffer significant consequences that negatively impact the ability of females to reproduce. To understand the physiologic consequences of surviving infection with Pd, we assessed differences in wing damage, mass-specific resting metabolic rate, and reproductive rate between little brown myotis ( Myotis lucifugus) that survived a winter in captivity after inoculation with Pd (WNS survivors) and comparable, uninfected bats. Survivors of WNS had significantly more damaged wing tissue and displayed elevated mass-specific metabolic rates compared with Pd-uninfected bats after emergence from hibernation. The WNS survivors and Pd-uninfected bats did not significantly differ in their reproductive capacity, at least in captivity. However, our metabolic data demonstrated greater energetic costs during spring in WNS survivors compared with uninfected bats, which may have led to other consequences for postpartum fitness. We suggest that, after surviving the energetic constraints of winter, temperate hibernating bats infected with Pd faced a second energetic bottleneck after emerging from hibernation.
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130
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Mahlert B, Gerritsmann H, Stalder G, Ruf T, Zahariev A, Blanc S, Giroud S. Implications of being born late in the active season for growth, fattening, torpor use, winter survival and fecundity. eLife 2018; 7:31225. [PMID: 29458712 PMCID: PMC5819945 DOI: 10.7554/elife.31225] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 01/10/2018] [Indexed: 12/05/2022] Open
Abstract
For hibernators, being born late in the active season may have important effects on growth and fattening, hence on winter survival and reproduction. This study investigated differences in growth, fattening, energetic responses, winter survival and fecundity between early-born (‘EB’) and late-born (‘LB’) juvenile garden dormice (Eliomys quercinus). LB juveniles grew and gained mass twice as fast as EB individuals. Torpor use was low during intensive growth, that are, first weeks of body mass gain, but increased during pre-hibernation fattening. LB juveniles showed higher torpor use, reached similar body sizes but lower fat content than EB individuals before hibernation. Finally, LB individuals showed similar patterns of hibernation, but higher proportion of breeders during the following year than EB dormice. These results suggest that torpor is incompatible with growth but promotes fattening and consolidates pre-hibernation fat depots. In garden dormice, being born late in the reproductive season is associated with a fast life history. Garden dormice are small rodents which are common in European woodlands. They were historically widespread from Portugal in the west to the Urals (Russia) in the east. However they are now largely confined to western Europe with north-eastern and eastern populations having become scattered and fragmented. During the course of a year in northern and central Europe, they make the most of the warm season to fatten up and to produce up to two litters of youngsters. When winter comes, dormice enter hibernation, sometimes for more than six months. During this time, they must rely on their fat reserves to survive. Every year, the young from the second litter have less time to prepare for the winter compared to their siblings born earlier in the season. So, how do they still manage to get ready on time for hibernation? Here, Mahlert et al. studied captive pups from first and second litters for their first year, following them as they grew up, entered and then emerged from their first hibernation. The late-born individuals developed nearly twice as fast as the ones born early in the season. In fact, both reached a similar body size, but the second-litter dormice had less fat reserves. Just before their first winter, both early- and late-born animals increasingly started to enter torpor – short and daily resting-like periods when the body slows down. Torpor rarely happens when animals are growing (because growth requires a warm body), but it is useful to help storing and consolidating fat before the cold months. Late-born dormice experienced more torpor on average than their first-litter peers. Both groups survived their first hibernation; but when they emerged, late-born individuals were more likely to reproduce that year. In other words, the dormice which grew quickly might also have sexually matured earlier. This could suggest that animals born later in the season have a faster life history: they grow rapidly, reproduce quickly but may die younger than their early-born peers. Mahlert et al. highlighted how early-life events can shape the course of animals’ existences and influence how their bodies operate. It remains to be examined how these circumstances may affect the individuals in the longer term, and perhaps even their descendants.
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Affiliation(s)
- Britta Mahlert
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Hanno Gerritsmann
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Gabrielle Stalder
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Alexandre Zahariev
- Université de Strasbourg, IPHC, Strasbourg, France.,CNRS, UMR7178, Strasbourg, France
| | - Stéphane Blanc
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.,Université de Strasbourg, IPHC, Strasbourg, France.,CNRS, UMR7178, Strasbourg, France
| | - Sylvain Giroud
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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131
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Flexibility is the key: metabolic and thermoregulatory behaviour in a small endotherm. J Comp Physiol B 2018; 188:553-563. [DOI: 10.1007/s00360-017-1140-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/30/2017] [Accepted: 12/12/2017] [Indexed: 10/18/2022]
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132
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Horii Y, Shiina T, Shimizu Y. The Mechanism Enabling Hibernation in Mammals. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1081:45-60. [PMID: 30288703 DOI: 10.1007/978-981-13-1244-1_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Some rodents including squirrels and hamsters undergo hibernation. During hibernation, body temperature drops to only a few degrees above ambient temperature. The suppression of whole-body energy expenditure is associated with regulated, but not passive, reduction of cellular metabolism. The heart retains the ability to beat constantly, although body temperature drops to less than 10 °C during hibernation. Cardiac myocytes of hibernating mammals are characterized by reduced Ca2+ entry into the cell membrane and a concomitant enhancement of Ca2+ release from and reuptake by the sarcoplasmic reticulum. These adaptive changes would help in preventing excessive Ca2+ entry and its overload and in maintaining the resting levels of intracellular Ca2+. Adaptive changes in gene expression in the heart prior to hibernation may be indispensable for acquiring cold resistance. In addition, protective effects of cold-shock proteins are thought to have an important role. We recently reported the unique expression pattern of cold-inducible RNA-binding protein (CIRP) in the hearts of hibernating hamsters. The CIRP mRNA is constitutively expressed in the heart of a nonhibernating euthermic hamster with several different forms probably due to alternative splicing. The short product contained the complete open reading frame for full-length CIRP, while the long product had inserted sequences containing a stop codon, suggesting production of a C-terminal deletion isoform of CIRP. In contrast to nonhibernating hamsters, only the short product was found in hibernating animals. Thus, these results indicate that CIRP expression in the hamster heart is regulated at the level of alternative splicing, which would permit a rapid increment of functional CIRP when entering hibernation. We will summarize the current understanding of the cold-resistant property of the heart in hibernating animals.
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Affiliation(s)
- Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.
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133
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JURCZYSZYN M, MARCHEWKA A, CZAPRACKA A, KARMIŃSKA L. Changes in body mass of postweaning juveniles of the edible dormouse,Glis glis (L.), in captivity. TURK J ZOOL 2018. [DOI: 10.3906/zoo-1704-29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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134
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Tissier ML, Kletty F, Handrich Y, Habold C. Monocultural sowing in mesocosms decreases the species richness of weeds and invertebrates and critically reduces the fitness of the endangered European hamster. Oecologia 2017; 186:589-599. [PMID: 29209843 DOI: 10.1007/s00442-017-4025-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 11/22/2017] [Indexed: 12/12/2022]
Abstract
Intensive cereal monoculture is currently the main cause of biodiversity decline in Europe. However, it is difficult to disentangle the effects of intensive monoculture (e.g. pesticide use, mechanical ploughing and reduced protective cover), let alone evaluate how far the reduction of crop diversity affects biodiversity. It remains unclear to which extent the consequent decrease in food resources affects farmland biodiversity, and particularly vertebrate species. We therefore designed this study in mesocosms to investigate the effects of monoculture crops (organic wheat or corn seeds) and mixed crops (a combination of organic wheat, corn, sunflower and alfalfa seeds) on (1) the species richness of weeds and invertebrates and (2) the reproductive success of the European hamster (Cricetus cricetus), a critically endangered umbrella species of European farmlands. We found a negative impact of organic monoculture crops on plant and invertebrate species richness, with values respectively 38% and 28% lower than those obtained for mixed organic crops. The reproductive success of hamsters was reduced by 82% in monoculture mesocosms. These results highlight that monoculture per se can be detrimental for farmland biodiversity (i.e. from plants to vertebrates), even before taking into account the use of pesticide and mechanization. We believe that future research should further consider how food reduction in agroecosystems affects farmland wildlife, including vertebrates. Moreover, we argue that conservation actions must focus on restoring plant diversity on farmland to reverse the observed trend in farmland wildlife decline.
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Affiliation(s)
- Mathilde L Tissier
- Université de Strasbourg, CNRS, IPHC, UMR 7178, 67000, Strasbourg, France.
| | - Florian Kletty
- Université de Strasbourg, CNRS, IPHC, UMR 7178, 67000, Strasbourg, France
| | - Yves Handrich
- Université de Strasbourg, CNRS, IPHC, UMR 7178, 67000, Strasbourg, France
| | - Caroline Habold
- Université de Strasbourg, CNRS, IPHC, UMR 7178, 67000, Strasbourg, France
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135
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Barros PA, Ribeiro C, CAbral JA. Winter Activity of Bats in Mediterranean Peri-Urban Deciduous Forests. ACTA CHIROPTEROLOGICA 2017. [DOI: 10.3161/15081109acc2017.19.2.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Paulo A. Barros
- Laboratory of Applied Ecology, University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
- Centre for the Research and Technology of Agro-Environment and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Cátia Ribeiro
- Laboratory of Applied Ecology, University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - João A. CAbral
- Laboratory of Applied Ecology, University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
- Centre for the Research and Technology of Agro-Environment and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
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136
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Seasonal energetics and torpor use in North American flying squirrels. J Therm Biol 2017; 70:46-53. [DOI: 10.1016/j.jtherbio.2017.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 10/04/2017] [Accepted: 10/21/2017] [Indexed: 11/18/2022]
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137
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Siutz C, Nemeth M, Wagner KH, Quint R, Ruf T, Millesi E. Effects of food store quality on hibernation performance in common hamsters. PLoS One 2017; 12:e0185913. [PMID: 29045417 PMCID: PMC5646777 DOI: 10.1371/journal.pone.0185913] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 09/21/2017] [Indexed: 11/18/2022] Open
Abstract
Hibernating animals can adjust torpor expression according to available energy reserves. Besides the quantity, the quality of energy reserves could play an important role for overwintering strategies. Common hamsters are food-storing hibernators and show high individual variation in hibernation performance, which might be related to the quality of food hoards in the hibernacula. In this study, we tested the effects of food stores high in fat content, particularly polyunsaturated fatty acids (PUFAs), on hibernation patterns under laboratory conditions. Control animals received standard rodent pellets only, while in the other group pellets were supplemented with sunflower seeds. We recorded body temperature during winter using subcutaneously implanted data loggers, documented total food consumption during winter, and analysed PUFA proportions in white adipose tissue (WAT) before and after the winter period. About half of the individuals in both groups hibernated and torpor expression did not differ between these animals. Among the high-fat group, however, individuals with high sunflower seeds intake strongly reduced the time spent in deep torpor. PUFA proportions in WAT decreased during winter in both groups and this decline was positively related to the time an individual spent in deep torpor. Sunflower seeds intake dampened the PUFA decline resulting in higher PUFA levels in animals of the high-fat group after winter. In conclusion, our results showed that common hamsters adjusted torpor expression and food intake in relation to the total energy of food reserves, underlining the importance of food hoard quality on hibernation performance.
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Affiliation(s)
- Carina Siutz
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- * E-mail:
| | - Matthias Nemeth
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
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138
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Boyles JG, Boyles E, Dunlap RK, Johnson SA, Brack V. Long-term microclimate measurements add further evidence that there is no “optimal” temperature for bat hibernation. Mamm Biol 2017. [DOI: 10.1016/j.mambio.2017.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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139
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Hoelzl F, Cornils JS, Smith S, Moodley Y, Ruf T. Telomere dynamics in free-living edible dormice (Glis glis): the impact of hibernation and food supply. ACTA ACUST UNITED AC 2017; 219:2469-74. [PMID: 27535986 PMCID: PMC5004978 DOI: 10.1242/jeb.140871] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/02/2016] [Indexed: 01/01/2023]
Abstract
We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular damage and RTL shortening. However, although mitosis is arrested in mammals at low body temperatures, recent evidence points to accelerated RTL shortening during periodic re-warming (arousal) from torpor. Therefore, we hypothesized that these arousals during hibernation should have a negative effect on RTL. Here, we show that RTL was shortened in all animals over the course of ∼1 year, during which dormice hibernated for 7.5–11.4 months. The rate of periodic arousals, rather than the time spent euthermic during the hibernation season, was the best predictor of RTL shortening. This finding points to negative effects on RTL of the transition from low torpor to high euthermic body temperature and metabolic rate during arousals, possibly because of increased oxidative stress. The animals were, however, able to elongate their telomeres during the active season, when food availability was increased by supplemental feeding in a year of low natural food abundance. We conclude that in addition to their energetic costs, periodic arousals also lead to accelerated cellular damage in terms of RTL shortening. Although dormice are able to counteract and even over-compensate for the negative effects of hibernation, restoration of RTL appears to be energetically costly. Highlighted Article: Telomeres in edible dormice shorten over the hibernation season, but these long-lived rodents are able to fully restore telomeres during summer if food supply is sufficient.
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Affiliation(s)
- Franz Hoelzl
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Jessica S Cornils
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Steve Smith
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Yoshan Moodley
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
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140
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Mayberry HW, McGuire LP, Willis CKR. Body temperatures of hibernating little brown bats reveal pronounced behavioural activity during deep torpor and suggest a fever response during white-nose syndrome. J Comp Physiol B 2017; 188:333-343. [PMID: 28766065 DOI: 10.1007/s00360-017-1119-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/18/2017] [Accepted: 07/25/2017] [Indexed: 01/06/2023]
Abstract
Hibernating animals use torpor [reduced body temperature (T b) and metabolic rate] to reduce energy expenditure during winter. Periodic arousals to normal T b are energetically expensive, so hibernators trade off arousal benefits against energetic costs. This is especially important for bats with white-nose syndrome (WNS), a fungal disease causing increased arousal frequency. Little brown bats (Myotis lucifugus) with WNS show upregulation of endogenous pyrogens and sickness behaviour. Therefore, we hypothesized that WNS should cause a fever response characterized by elevated T b. Hibernators could also accrue some benefits of arousals with minimal T b increase, thus avoiding full arousal costs. We compared skin temperature (T sk) of captive Myotis lucifugus inoculated with the WNS-causing fungus to T sk of sham-inoculated controls. Infected bats re-warmed to higher T sk during arousals which is consistent with a fever response. Torpid T sk did not differ. During what we term "cold arousals", bats exhibited movement following T sk increases of only 2.2 ± 0.3 °C, compared to >20 °C increases during normal arousals. Cold arousals occurred in both infected and control bats, suggesting they are not a pathophysiological consequence of WNS. Fever responses are energetically costly and could exacerbate energy limitation and premature fat depletion for bats with WNS. Cold arousals could represent an energy-saving mechanism for both healthy and WNS-affected bats when complete arousals are unnecessary or too costly. A few cold arousals were observed mid-hibernation, typically in response to disturbances. Cold arousals may, therefore, represent a voluntary restriction of arousal temperature instead of loss of thermoregulatory control.
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Affiliation(s)
- Heather W Mayberry
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada. .,Department of Ecology and Evolutionary Biology, University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON, L5L 1C6, Canada.
| | - Liam P McGuire
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada.,Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Craig K R Willis
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada
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141
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Czenze ZJ, Brigham RM, Hickey AJR, Parsons S. Stressful summers? Torpor expression differs between high- and low-latitude populations of bats. J Mammal 2017. [DOI: 10.1093/jmammal/gyx071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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142
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Czenze ZJ, Brigham RM, Hickey AJR, Parsons S. Winter climate affects torpor patterns and roost choice in New Zealand lesser short‐tailed bats. J Zool (1987) 2017. [DOI: 10.1111/jzo.12486] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Z. J. Czenze
- School of Biological Sciences University of Auckland Auckland New Zealand
| | - R. M. Brigham
- Department of Biology University of Regina Regina SK Canada
| | - A. J. R. Hickey
- School of Biological Sciences University of Auckland Auckland New Zealand
| | - S. Parsons
- School of Biological Sciences University of Auckland Auckland New Zealand
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143
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Czenze ZJ, Jonasson KA, Willis CKR. Thrifty Females, Frisky Males: Winter Energetics of Hibernating Bats from a Cold Climate. Physiol Biochem Zool 2017. [DOI: 10.1086/692623] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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144
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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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145
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Review: Deciphering animal robustness. A synthesis to facilitate its use in livestock breeding and management. Animal 2017; 11:2237-2251. [PMID: 28462770 DOI: 10.1017/s175173111700088x] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
As the environments in which livestock are reared become more variable, animal robustness becomes an increasingly valuable attribute. Consequently, there is increasing focus on managing and breeding for it. However, robustness is a difficult phenotype to properly characterise because it is a complex trait composed of multiple components, including dynamic elements such as the rates of response to, and recovery from, environmental perturbations. In this review, the following definition of robustness is used: the ability, in the face of environmental constraints, to carry on doing the various things that the animal needs to do to favour its future ability to reproduce. The different elements of this definition are discussed to provide a clearer understanding of the components of robustness. The implications for quantifying robustness are that there is no single measure of robustness but rather that it is the combination of multiple and interacting component mechanisms whose relative value is context dependent. This context encompasses both the prevailing environment and the prevailing selection pressure. One key issue for measuring robustness is to be clear on the use to which the robustness measurements will employed. If the purpose is to identify biomarkers that may be useful for molecular phenotyping or genotyping, the measurements should focus on the physiological mechanisms underlying robustness. However, if the purpose of measuring robustness is to quantify the extent to which animals can adapt to limiting conditions then the measurements should focus on the life functions, the trade-offs between them and the animal's capacity to increase resource acquisition. The time-related aspect of robustness also has important implications. Single time-point measurements are of limited value because they do not permit measurement of responses to (and recovery from) environmental perturbations. The exception being single measurements of the accumulated consequence of a good (or bad) adaptive capacity, such as productive longevity and lifetime efficiency. In contrast, repeated measurements over time have a high potential for quantification of the animal's ability to cope with environmental challenges. Thus, we should be able to quantify differences in adaptive capacity from the data that are increasingly becoming available with the deployment of automated monitoring technology on farm. The challenge for future management and breeding will be how to combine various proxy measures to obtain reliable estimates of robustness components in large populations. A key aspect for achieving this is to define phenotypes from consideration of their biological properties and not just from available measures.
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146
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Klüg-Baerwald BJ, Lausen CL, Willis CKR, Brigham RM. Home is where you hang your bat: winter roost selection by prairie-living big brown bats. J Mammal 2017. [DOI: 10.1093/jmammal/gyx039] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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147
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Torpor patterns in common hamsters with and without access to food stores. J Comp Physiol B 2017; 187:881-888. [PMID: 28417150 PMCID: PMC5486536 DOI: 10.1007/s00360-017-1093-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 03/14/2017] [Accepted: 04/06/2017] [Indexed: 01/15/2023]
Abstract
Hibernating species significantly reduce energy expenditure during winter by entering torpor. Nevertheless, the various benefits of hibernation might be counteracted by negative effects of torpor such as immune depression, oxidative stress, or neuronal impairment. Considering these trade-offs, adequate energy reserves could allow animals to reduce the time spent in torpor or the extent of metabolic depression. Common hamsters use food stores during hibernation and previously documented high individual variations in body temperature patterns during winter could, therefore, be related to differences in external energy reserves. In this study, we manipulated the availability of food stores under laboratory conditions to investigate potential effects on hibernation patterns. Female hamsters were kept in artificial burrows in climate chambers and subcutaneous temperature was recorded using implanted data loggers. One group had access to large food stores, whereas another group received daily food portions which were removed on the next day if not consumed. Almost all hamsters without access to food stores hibernated, while less than half of the individuals with food stores entered deep torpor. Individuals without food hoards additionally expressed more short torpor bouts and exhibited lower minimum subcutaneous temperatures during torpor than those with food stores. Thus, individuals confronted with lacking food reserves were more likely to hibernate and additionally saved energy by entering short torpor bouts more frequently and remaining at lower subcutaneous temperature both during torpor and euthermic periods. In conclusion, our results demonstrate that food store availability affects torpor expression and also highlight variation in torpor patterns and energy-saving strategies in common hamsters.
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148
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149
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Tissier ML, Handrich Y, Dallongeville O, Robin JP, Habold C. Diets derived from maize monoculture cause maternal infanticides in the endangered European hamster due to a vitamin B3 deficiency. Proc Biol Sci 2017; 284:20162168. [PMID: 28100816 PMCID: PMC5310035 DOI: 10.1098/rspb.2016.2168] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/19/2016] [Indexed: 02/03/2023] Open
Abstract
From 1735 to 1940, maize-based diets led to the death of hundreds of thousands of people from pellagra, a complex disease caused by tryptophan and vitamin B3 deficiencies. The current cereal monoculture trend restricts farmland animals to similarly monotonous diets. However, few studies have distinguished the effects of crop nutritional properties on the reproduction of these species from those of other detrimental factors such as pesticide toxicity or agricultural ploughing. This study shows that maize-based diets cause high rates of maternal infanticides in the European hamster, a farmland species on the verge of extinction in Western Europe. Vitamin B3 supplementation is shown to effectively restore reproductive success in maize-fed females. This study pinpoints how nutritional deficiencies caused by maize monoculture could affect farmland animal reproduction and hence their fitness.
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Affiliation(s)
- Mathilde L Tissier
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Yves Handrich
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | | | - Jean-Patrice Robin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Caroline Habold
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
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150
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DeGregorio BA, Tuberville TD, Kennamer RA, Harris BB, Brisbin IL. Spring emergence of Eastern Box Turtles (Terrapene carolina): influences of individual variation and scale of temperature correlates. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0149] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many organisms spend considerable time in dormancy to avoid stressful environmental conditions. Understanding the timing and triggers of dormancy behavior is critical for understanding an animal’s life history and behavior. Eastern Box Turtles (Terrapene carolina (L., 1758)) avoid winter temperatures by burrowing into the soil and remaining dormant. Identifying the proximate environmental cues that trigger emergence can improve conservation efforts by reducing potential aboveground turtle mortality. During a 17-year study, half of all variation in emergence timing was attributed to individual variation and the habitat that they occupied during dormancy. We suggest that individual variation in emergence timing is common within populations and confounds efforts to identify reliable emergence cues. Additionally, the scale of meteorological data limits the ability to identify emergence predictors. Using data from temperature loggers placed at dormancy locations, we found that surface air temperatures, averaged over the 5 days prior to emergence, were more strongly related to emergence probability than any variables derived from local weather stations. Turtles generally did not emerge from dormancy until the 5-day mean surface temperatures measured at dormancy sites reached approximately 15 °C. Our results suggest that individuals respond differently to environmental thresholds for emergence and individuals may be characterized as risk-taking or risk-aversive.
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Affiliation(s)
- Brett A. DeGregorio
- University of Georgia’s Savannah River Ecology Laboratory, Aiken, SC 29802, USA
| | | | - Robert A. Kennamer
- University of Georgia’s Savannah River Ecology Laboratory, Aiken, SC 29802, USA
| | - Bess B. Harris
- University of Georgia’s Savannah River Ecology Laboratory, Aiken, SC 29802, USA
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, FL 32653, USA
| | - I. Lehr Brisbin
- University of Georgia’s Savannah River Ecology Laboratory, Aiken, SC 29802, USA
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