1
|
Wen T, Koonin EV, Cheong KH. An alternating active-dormitive strategy enables disadvantaged prey to outcompete the perennially active prey through Parrondo's paradox. BMC Biol 2021; 19:168. [PMID: 34425802 PMCID: PMC8383410 DOI: 10.1186/s12915-021-01097-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/14/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Dormancy is widespread in nature, but while it can be an effective adaptive strategy in fluctuating environments, the dormant forms are costly due to the inability to breed and the relatively high energy consumption. We explore mathematical models of predator-prey systems, in order to assess whether dormancy can be an effective adaptive strategy to outcompete perennially active (PA) prey, even when both forms of the dormitive prey (active and dormant) are individually disadvantaged. RESULTS We develop a dynamic population model by introducing an additional dormitive prey population to the existing predator-prey model which can be active (active form) and enter dormancy (dormant form). In this model, both forms of the dormitive prey are individually at a disadvantage compared to the PA prey and thus would go extinct due to their low growth rate, energy waste on the production of dormant prey, and the inability of the latter to grow autonomously. However, the dormitive prey can paradoxically outcompete the PA prey with superior traits and even cause its extinction by alternating between the two losing strategies. We observed higher fitness of the dormitive prey in rich environments because a large predator population in a rich environment cannot be supported by the prey without adopting an evasive strategy, that is, dormancy. In such environments, populations experience large-scale fluctuations, which can be survived by dormitive but not by PA prey. CONCLUSION We show that dormancy can be an effective adaptive strategy to outcompete superior prey, recapitulating the game-theoretic Parrondo's paradox, where two losing strategies combine to achieve a winning outcome. We suggest that the species with the ability to switch between the active and dormant forms can dominate communities via competitive exclusion.
Collapse
Affiliation(s)
- Tao Wen
- Science, Mathematics and Technology Cluster, Singapore University of Technology and Design (SUTD), 8 Somapah Road, S487372, Singapore, Singapore
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA
| | - Kang Hao Cheong
- Science, Mathematics and Technology Cluster, Singapore University of Technology and Design (SUTD), 8 Somapah Road, S487372, Singapore, Singapore.
| |
Collapse
|
2
|
Dausmann KH, Levesque DL, Wein J, Nowack J. Ambient Temperature Cycles Affect Daily Torpor and Hibernation Patterns in Malagasy Tenrecs. Front Physiol 2020; 11:522. [PMID: 32547412 PMCID: PMC7270353 DOI: 10.3389/fphys.2020.00522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/28/2020] [Indexed: 11/30/2022] Open
Abstract
Hibernation and daily torpor (heterothermy) allow endotherms to cope with demanding environmental conditions. The depth and duration of torpor bouts vary considerably between tropical and temperate climates, and tropical hibernators manage to cope with a wider spectrum of ambient temperature (Ta) regimes during heterothermy. As cycles in Ta can have profound effects on activity and torpor patterns as well as energy expenditure, we examined how these characteristics are affected by daily fluctuating versus constant Ta in a tropical hibernator, the lesser hedgehog tenrec (Echinops telfairi). Throughout the study, regardless of season, the tenrecs became torpid every day. In summer, E. telfairi used daily fluctuations in Ta to passively rewarm from daily torpor, which led to synchrony in the activity phases and torpor bouts between individuals and generally decreased energy expenditure. In contrast, animals housed at constant Ta showed considerable variation in timing and they had to invest more energy through endogenous heat production. During the hibernation season (winter) E. telfairi hibernated for several months in constant, as well as in fluctuating Ta and, as in summer, under fluctuating Ta arousals were much more uniform and showed less variation in timing compared to constant temperature regimes. The timing of torpor is not only important for its effective use, but synchronization of activity patterns could also be essential for social interactions, and successful foraging bouts. Our results highlight that Ta cycles can be an effective zeitgeber for activity and thermoregulatory rhythms throughout the year and that consideration should be given to the choice of temperature regime when studying heterothermy under laboratory conditions.
Collapse
Affiliation(s)
- Kathrin H Dausmann
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Danielle L Levesque
- School of Biology and Ecology, University of Maine, Orono, ME, United States
| | - Jens Wein
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| |
Collapse
|
3
|
Nowack J, Levesque DL, Reher S, Dausmann KH. Variable Climates Lead to Varying Phenotypes: “Weird” Mammalian Torpor and Lessons From Non-Holarctic Species. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00060] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Andrews MT. Molecular interactions underpinning the phenotype of hibernation in mammals. J Exp Biol 2019; 222:222/2/jeb160606. [DOI: 10.1242/jeb.160606] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT
Mammals maintain a constant warm body temperature, facilitating a wide variety of metabolic reactions. Mammals that hibernate have the ability to slow their metabolism, which in turn reduces their body temperature and leads to a state of hypothermic torpor. For this metabolic rate reduction to occur on a whole-body scale, molecular interactions that change the physiology of cells, tissues and organs are required, resulting in a major departure from normal mammalian homeostasis. The aim of this Review is to cover recent advances in the molecular biology of mammalian hibernation, including the role of small molecules, seasonal changes in gene expression, cold-inducible RNA-binding proteins, the somatosensory system and emerging information on hibernating primates. To underscore the importance of differential gene expression across the hibernation cycle, mRNA levels for 14,261 ground squirrel genes during periods of activity and torpor are made available for several tissues via an interactive transcriptome browser. This Review also addresses recent findings on molecular interactions responsible for multi-day survival of near-freezing body temperatures, single-digit heart rates and a slowed metabolism that greatly reduces oxygen consumption. A better understanding of how natural hibernators survive these physiological extremes is beginning to lead to innovations in human medicine.
Collapse
Affiliation(s)
- Matthew T. Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| |
Collapse
|
6
|
Hadj‐Moussa H, Storey KB. Bringing nature back: using hibernation to reboot organ preservation. FEBS J 2018; 286:1094-1100. [DOI: 10.1111/febs.14683] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/14/2018] [Accepted: 10/17/2018] [Indexed: 12/19/2022]
|
7
|
Blanco MB, Dausmann KH, Faherty SL, Yoder AD. Tropical heterothermy is “cool”: The expression of daily torpor and hibernation in primates. Evol Anthropol 2018; 27:147-161. [DOI: 10.1002/evan.21588] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Anne D. Yoder
- Duke Lemur Center; Durham North Carolina
- Department of Biology; Duke University; Durham North Carolina
| |
Collapse
|
8
|
Faherty SL, Villanueva‐Cañas JL, Blanco MB, Albà MM, Yoder AD. Transcriptomics in the wild: Hibernation physiology in free‐ranging dwarf lemurs. Mol Ecol 2018; 27:709-722. [DOI: 10.1111/mec.14483] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 12/30/2022]
Affiliation(s)
| | - José Luis Villanueva‐Cañas
- Institute of Evolutionary Biology (CSIC‐Universitat Pompeu Fabra) Barcelona Spain
- Evolutionary Genomics Group Research Programme on Biomedical Informatics (GRIB) Hospital del Mar Research Institute (IMIM) Universitat Pompeu Fabra (UPF) Barcelona Spain
| | | | - M. Mar Albà
- Evolutionary Genomics Group Research Programme on Biomedical Informatics (GRIB) Hospital del Mar Research Institute (IMIM) Universitat Pompeu Fabra (UPF) Barcelona Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
| | - Anne D. Yoder
- Department of Biology Duke University Durham NC USA
- Duke Lemur Center Durham NC USA
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Steffens KJE, Jacques Rakotondranary S, Ratovonamana YR, Ganzhorn JU. Vegetation Thresholds for the Occurrence and Dispersal of Microcebus griseorufus in Southwestern Madagascar. INT J PRIMATOL 2017. [DOI: 10.1007/s10764-017-0003-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
11
|
Welman S, Tuen AA, Lovegrove BG. Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers. Front Physiol 2017; 8:745. [PMID: 29018365 PMCID: PMC5623056 DOI: 10.3389/fphys.2017.00745] [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: 04/30/2017] [Accepted: 09/12/2017] [Indexed: 01/26/2023] Open
Abstract
The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size and habitat stability since the Late Eocene, we selected western tarsiers (Cephalopachus bancanus) from the island of Borneo. Being the sister clade to Strepsirrhini and basal in Haplorrhini (monkeys and apes), we hypothesized that C. bancanus might have retained the heterothermic capacity observed in several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss and the percentage of heat dissipated through evaporation, at ambient temperatures between 22 and 35°C in fresh-caught wild animals (126.1 ± 2.4 g). We also measured core body temperatures in free-ranging animals. The thermoneutral zone was 25-30°C and the basal metabolic rate was 3.52 ± 0.06 W.kg-1 (0.65 ± 0.01 ml O2.g-1.h-1). There was no evidence of adaptive heterothermy in either the laboratory data or the free-ranging data. Instead, animals appeared to be cold sensitive (Tb ~ 31°C) at the lowest temperatures. We discuss possible reasons for the apparent lack of heterothermy in tarsiers, and identify putative heterotherms within Platyrrhini. We also document our concern for the vulnerability of C. bancanus to future temperature increases associated with global warming.
Collapse
Affiliation(s)
- Shaun Welman
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Andrew A. Tuen
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - Barry G. Lovegrove
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| |
Collapse
|
12
|
Bethge J, Wist B, Stalenberg E, Dausmann K. Seasonal adaptations in energy budgeting in the primate Lepilemur leucopus. J Comp Physiol B 2017; 187:827-834. [PMID: 28314947 DOI: 10.1007/s00360-017-1082-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 12/03/2016] [Accepted: 02/26/2017] [Indexed: 11/25/2022]
Abstract
The spiny forest of South Madagascar is one of the driest and most unpredictable habitats in Africa. The small-bodied, nocturnal primate Lepilemur leucopus lives in this harsh habitat with high diurnal and seasonal changes in ambient temperature. In this study, we investigated seasonal adaptions in energy budgeting of L. leucopus, which allow it to live under these conditions by measuring resting metabolic rate using open-flow respirometry. No signs of heterothermy were detected, and resting metabolic rate was significantly lower in the warmer wet season than in the colder dry season. In fact, L. leucopus possesses one of the lowest mass-specific metabolic rates measured so far for an endotherm, probably the result of adaptations to its habitat and folivorous and potentially toxic diet. Surprisingly, we identified a shift of the thermoneutral zone from between 25 and 30 °C in the wet season to between 29 and 32 °C in the cool dry season. L. leucopus seems to be more affected by the hot daytime temperatures during the dry season and thermoregulation seems to be more costly during this time, which makes this shift of the thermoneutral zone advantageous. Our findings suggest that L. leucopus has a very small scope to unfavorable conditions, making it highly vulnerable, e.g., to changing conditions due to climate change.
Collapse
Affiliation(s)
- Janina Bethge
- Zoological Institute, Functional Ecology, Biocenter Grindel, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany.
| | - Bianca Wist
- Zoological Institute, Functional Ecology, Biocenter Grindel, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
| | - Eleanor Stalenberg
- Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Kathrin Dausmann
- Zoological Institute, Functional Ecology, Biocenter Grindel, University Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
| |
Collapse
|
13
|
Dausmann KH, Warnecke L. Primate Torpor Expression: Ghost of the Climatic Past. Physiology (Bethesda) 2016; 31:398-408. [DOI: 10.1152/physiol.00050.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Torpor, the controlled depression of virtually all bodily function during scarce periods, was verified in primates under free-ranging conditions less than two decades ago. The large variety of different torpor patterns found both within and among closely related species is particularly remarkable. To help unravel the cause of these variable patterns, our review investigates primate torpor use within an evolutionary framework. First, we provide an overview of heterothermic primate species, focusing on the Malagasy lemurs, and discuss their use of daily torpor or hibernation in relation to habitat type and climatic conditions. Second, we investigate environmental characteristics that may have been involved in shaping the high variability of torpor expression found in lemurs today. Third, we examine potential triggers for torpor use in lemurs. We propose the “torpor refugia hypothesis” to illustrate how disparate primate torpor patterns possibly evolved in response to environmental cues during glacial periods, when animals were restricted to different refuge habitats along riverine corridors. For example, individuals enduring harsher conditions at higher altitudes likely developed seasonal hibernation, whereas those inhabiting lower elevation river catchments might have coped with unfavorable conditions by employing daily torpor. The ultimate stimuli triggering torpor use today likely differ between the different habitats of Madagascar. The broad diversity of torpor patterns in lemurs among closely related species, both within the same and in distinctly different habitat types, provides an ideal base for research into the stimuli for torpor use in endotherms in general. Our hypothesis highlights the importance of considering the environmental conditions under which ecosystems and species evolved when trying to explain physiological adaptations seen today.
Collapse
Affiliation(s)
- Kathrin H. Dausmann
- Zoological Institute, Functional Ecology, University Hamburg, Hamburg, Germany
| | - Lisa Warnecke
- Zoological Institute, Functional Ecology, University Hamburg, Hamburg, Germany
| |
Collapse
|
14
|
Population- and Individual-Level Dynamics of the Intestinal Microbiota of a Small Primate. Appl Environ Microbiol 2016; 82:3537-3545. [PMID: 27060114 PMCID: PMC4959157 DOI: 10.1128/aem.00559-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 03/31/2016] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Longitudinal sampling for intestinal microbiota in wild animals is difficult, leading to a lack of information on bacterial dynamics occurring in nature. We studied how the composition of microbiota communities changed temporally in free-ranging small primates, rufous mouse lemurs (Microcebus rufus). We marked and recaptured mouse lemurs during their mating season in Ranomafana National Park in southeastern mountainous rainforests of Madagascar for 2 years and determined the fecal microbiota compositions of these mouse lemurs with MiSeq sequencing. We collected 160 fecal samples from 71 animals and had two or more samples from 39 individuals. We found small, but statistically significant, effects of site and age on microbiota richness and diversity and effects of sex, year, and site on microbiota composition, while the within-year temporal trends were less clear. Within-host microbiota showed pervasive variation in intestinal bacterial community composition, especially during the second study year. We hypothesize that the biological properties of mouse lemurs, including their small body size and fast metabolism, may contribute to the temporal intraindividual-level variation, something that should be testable with more-extensive sampling regimes. IMPORTANCE While microbiome research has blossomed in recent years, there is a lack of longitudinal studies on microbiome dynamics on free-ranging hosts. To fill this gap, we followed mouse lemurs, which are small heterothermic primates, for 2 years. Most studied animals have shown microbiota to be stable over the life span of host individuals, but some previous research also found ample within-host variation in microbiota composition. Our study used a larger sample size than previous studies and a study setting well suited to track within-host variation in free-ranging mammals. Despite the overall microbiota stability at the population level, the microbiota of individual mouse lemurs can show large-scale changes in composition in time periods as short as 2 days, suggesting caution in inferring individual-level patterns from population-level data.
Collapse
|
15
|
Hibernation in the pygmy slow loris (Nycticebus pygmaeus): multiday torpor in primates is not restricted to Madagascar. Sci Rep 2015; 5:17392. [PMID: 26633602 PMCID: PMC4668838 DOI: 10.1038/srep17392] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/29/2015] [Indexed: 01/20/2023] Open
Abstract
Hibernation and short daily torpor are states of energy conservation with reduced metabolism and body temperature. Both hibernation, also called multiday torpor, and daily torpor are common among mammals and occur in at least 11 orders. Within the primates, there is a peculiar situation, because to date torpor has been almost exclusively reported for Malagasy lemurs. The single exception is the African lesser bushbaby, which is capable of daily torpor, but uses it only under extremely adverse conditions. For true hibernation, the geographical restriction was absolute. No primate outside of Madagascar was previously known to hibernate. Since hibernation is commonly viewed as an ancient, plesiomorphic trait, theoretically this could mean that hibernation as an overwintering strategy was lost in all other primates in mainland Africa, Asia, and the Americas. However, we hypothesized that a good candidate species for the use of hibernation, outside of Madagascar should be the pygmy slow loris (Nycticebus pygmaeus), a small primate inhabiting tropical forests. Here, we show that pygmy slow lorises exposed to natural climatic conditions in northern Vietnam during winter indeed undergo torpor lasting up to 63 h, that is, hibernation. Thus, hibernation has been retained in at least one primate outside of Madagascar.
Collapse
|
16
|
Seldin MM, Byerly MS, Petersen PS, Swanson R, Balkema-Buschmann A, Groschup MH, Wong GW. Seasonal oscillation of liver-derived hibernation protein complex in the central nervous system of non-hibernating mammals. ACTA ACUST UNITED AC 2015; 217:2667-79. [PMID: 25079892 DOI: 10.1242/jeb.095976] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mammalian hibernation elicits profound changes in whole-body physiology. The liver-derived hibernation protein (HP) complex, consisting of HP-20, HP-25 and HP-27, was shown to oscillate circannually, and this oscillation in the central nervous system (CNS) was suggested to play a role in hibernation. The HP complex has been found in hibernating chipmunks but not in related non-hibernating tree squirrels, leading to the suggestion that hibernation-specific genes may underlie the origin of hibernation. Here, we show that non-hibernating mammals express and regulate the conserved homologous HP complex in a seasonal manner, independent of hibernation. Comparative analyses of cow and chipmunk HPs revealed extensive biochemical and structural conservations. These include liver-specific expression, assembly of distinct heteromeric complexes that circulate in the blood and cerebrospinal fluid, and the striking seasonal oscillation of the HP levels in the blood and CNS. Central administration of recombinant HPs affected food intake in mice, without altering body temperature, physical activity levels or energy expenditure. Our results demonstrate that HP complex is not unique to the hibernators and suggest that the HP-regulated liver-brain circuit may couple seasonal changes in the environment to alterations in physiology.
Collapse
Affiliation(s)
- Marcus M Seldin
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mardi S Byerly
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pia S Petersen
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Roy Swanson
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anne Balkema-Buschmann
- Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany
| | - Martin H Groschup
- Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany
| | - G William Wong
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
17
|
Karanewsky CJ, Wright PC. A preliminary investigation of sleeping site selection and sharing by the brown mouse lemurMicrocebus rufusduring the dry season. J Mammal 2015. [DOI: 10.1093/jmammal/gyv143] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
18
|
van Breukelen F, Martin SL. The Hibernation Continuum: Physiological and Molecular Aspects of Metabolic Plasticity in Mammals. Physiology (Bethesda) 2015; 30:273-81. [DOI: 10.1152/physiol.00010.2015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mammals are often considered to be masters of homeostasis, with the ability to maintain a constant internal milieu, despite marked changes in the environment; however, many species exhibit striking physiological and biochemical plasticity in the face of environmental fluctuations. Here, we review metabolic depression and body temperature fluctuation in mammals, with a focus on the extreme example of hibernation in small-bodied eutherian species. Careful exploitation of the phenotypic plasticity of mammals with metabolic flexibility may provide the key to unlocking the molecular secrets of orchestrating and surviving reversible metabolic depression in less plastic species, including humans.
Collapse
Affiliation(s)
| | - Sandra L. Martin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| |
Collapse
|
19
|
Biggar KK, Wu CW, Tessier SN, Zhang J, Pifferi F, Perret M, Storey KB. Modulation of Gene Expression in Key Survival Pathways During Daily Torpor in the Gray Mouse Lemur, Microcebus murinus. GENOMICS PROTEOMICS & BIOINFORMATICS 2015; 13:111-8. [PMID: 26093281 PMCID: PMC4511780 DOI: 10.1016/j.gpb.2015.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/20/2015] [Indexed: 12/18/2022]
Abstract
A variety of mammals employ torpor as an energy-saving strategy in environments of marginal or severe stress either on a daily basis during their inactive period or on a seasonal basis during prolonged multi-day hibernation. Recently, a few Madagascar lemur species have been identified as the only primates that exhibit torpor; one of these is the gray mouse lemur (Microcebus murinus). To explore the regulatory mechanisms that underlie daily torpor in a primate, we analyzed the expression of 28 selected genes that represent crucial survival pathways known to be involved in squirrel and bat hibernation. Array-based real-time PCR was used to compare gene expression in control (aroused) versus torpid lemurs in five tissues including the liver, kidney, skeletal muscle, heart, and brown adipose tissue. Significant differences in gene expression during torpor were revealed among genes involved in glycolysis, fatty acid metabolism, antioxidant defense, apoptosis, hypoxia signaling, and protein protection. The results showed upregulation of select genes primarily in liver and brown adipose tissue. For instance, both tissues showed elevated gene expression of peroxisome proliferator activated receptor gamma (ppargc), ferritin (fth1), and protein chaperones during torpor. Overall, the data show that the expression of only a few genes changed during lemur daily torpor, as compared with the broader expression changes reported for hibernation in ground squirrels. These results provide an indication that the alterations in gene expression required for torpor in lemurs are not as extensive as those needed for winter hibernation in squirrel models. However, identification of crucial genes with altered expression that support lemur torpor provides key targets to be explored and manipulated toward a goal of translational applications of inducible torpor as a treatment option in human biomedicine.
Collapse
Affiliation(s)
- Kyle K Biggar
- Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Biochemistry Department, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Cheng-Wei Wu
- Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Department of Biology, Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Shannon N Tessier
- Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Department of Surgery & Center for Engineering in Medicine, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA
| | - Jing Zhang
- Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada
| | - Fabien Pifferi
- UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, 91800 Brunoy, France
| | - Martine Perret
- UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, 91800 Brunoy, France
| | - Kenneth B Storey
- Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada.
| |
Collapse
|
20
|
Blanco MB, Rasoazanabary E, Godfrey LR. Unpredictable environments, opportunistic responses: Reproduction and population turnover in two wild mouse lemur species (Microcebus rufus and M. griseorufus) from eastern and western Madagascar. Am J Primatol 2015; 77:936-947. [PMID: 26031477 DOI: 10.1002/ajp.22423] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Revised: 04/14/2015] [Accepted: 04/19/2015] [Indexed: 11/12/2022]
Abstract
Small-bodied, nocturnal mouse lemurs (Microcebus) are widespread across diverse forest habitats in Madagascar. They are strict seasonal breeders and can, depending on the habitat and species, undergo daily or prolonged torpor to minimize energy expenditure during periods of food and water scarcity. Duration of reproduction, number of litters per season and timing of births vary across individuals and species. The "polyestry-seasonality" hypothesis proposes that the duration of reproduction and number of litters per year are positively correlated with rainfall but negatively correlated with longevity, whereas the "hypervariability" hypothesis suggests that the duration of reproduction is negatively correlated with the degree of predictability of food resources. We test these hypotheses in two mouse lemur species inhabiting contrasting habitats, the brown mouse lemurs, Microcebus rufus, from Ranomafana (a less seasonal and more climatically predictable habitat) and the gray-brown mouse lemurs, M. griseorufus, from Beza Mahafaly (a more seasonal and less climatically predictable environment). We use capture/mark/recapture techniques and records of female reproductive status. We found evidence of polyestry at both study sites but faster population turnover and longer duration of the reproductive season at Beza Mahafaly. The "polyestry-seasonality" hypothesis is not supported but the "hypervariability" hypothesis could not be rejected. We conclude that reproductive output cannot be tied to climatic factors in a simple manner. Paradoxically, polyestry can be expressed in contrasting habitats: less seasonal forests where females can sustain multiple reproductive events, but also highly seasonal environments where females may not fatten sufficiently to sustain prolonged torpor but instead remain active throughout the year by relying on fallback resources. Am. J. Primatol. 77:936-947, 2015. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | | | - Laurie R Godfrey
- Department of Anthropology, University of Massachusetts, Amherst, Massachusetts
| |
Collapse
|
21
|
LeTallec T, Théry M, Perret M. Effects of light pollution on seasonal estrus and daily rhythms in a nocturnal primate. J Mammal 2015. [DOI: 10.1093/jmammal/gyv047] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
22
|
Affiliation(s)
- M. B. Blanco
- Duke Lemur Center; Durham NC USA
- Department of Animal Ecology and Conservation; University of Hamburg; Hamburg Germany
| | | |
Collapse
|
23
|
Affiliation(s)
- Julia Nowack
- Department of Animal Ecology and Conservation; Biocentre Grindel; University of Hamburg; Martin-Luther-King Platz 3 20146 Hamburg Germany
- Centre for Behavioural and Physiological Ecology, Zoology; University of New England; Armidale NSW 2351 Australia
| | - Kathrin H. Dausmann
- Department of Animal Ecology and Conservation; Biocentre Grindel; University of Hamburg; Martin-Luther-King Platz 3 20146 Hamburg Germany
| |
Collapse
|
24
|
Sommer S, Rakotondranary SJ, Ganzhorn JU. Maintaining microendemic primate species along an environmental gradient - parasites as drivers for species differentiation. Ecol Evol 2014; 4:4751-65. [PMID: 25558366 PMCID: PMC4278824 DOI: 10.1002/ece3.1311] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/10/2014] [Accepted: 10/10/2014] [Indexed: 11/07/2022] Open
Abstract
Understanding the drivers of species adaptations to changing environments on the one hand and the limits for hybridization on the other hand is among the hottest questions in evolutionary biology. Parasites represent one of the major selective forces driving host evolution and at least those with free-living stages are at the same time dependent on the ecological conditions of their host's habitat. Local immunological adaptations of host species to varying parasite pressure are therefore expected and might represent the genetic basis for ecological speciation and the maintenance of recently diverged species. Madagascar provides one of the rare examples where two partially sympatric primate species (Microcebus griseorufus, M. murinus) and their hybrids, as well as an allopatric species (M. cf rufus) live in close proximity along a very steep environmental gradient ranging from southern dry spiny bush to gallery forest to evergreen eastern humid rain forest, thus mimicking the situation encountered during extensions and retreats of vegetation formations under changing climatic conditions. This system was used to study parasite infection and immune gene (MHC) adaptations to varying parasite pressure that might provide selective advantages to pure species over hybrids. Parasite burdens increased with increasing humidity. M. griseorufus, M. murinus, and their hybrids but not M. rufus shared the same MHC alleles, indicating either retention of ancestral polymorphism or recent gene flow. The hybrids had much higher prevalence of intestinal parasites than either of the parent species living under identical environmental conditions. The different representation of parasites can indicate a handicap for hybrids that maintains species identities.
Collapse
Affiliation(s)
- Simone Sommer
- Evolutionary Genetics, Leibniz-Institute for Zoo- and Wildlife ResearchAlfred-Kowalke-Strasse 10, Berlin, 10315, Germany
- Institute for Experimental Ecology, University of UlmAlbert-Einstein Allee 11, Ulm, 89069, Germany
| | - Solofomalla Jacques Rakotondranary
- Department of Animal Ecology and Conservation, University of Hamburg, Biozentrum GrindelMartin-Luther-King Platz 3, Hamburg, 20146, Germany
| | - Jörg U Ganzhorn
- Department of Animal Ecology and Conservation, University of Hamburg, Biozentrum GrindelMartin-Luther-King Platz 3, Hamburg, 20146, Germany
| |
Collapse
|
25
|
Affiliation(s)
- Kathrin H. Dausmann
- Animal Ecology & Conservation Biocenter Grindel University Hamburg Hamburg Germany
| | - Julian Glos
- Animal Ecology & Conservation Biocenter Grindel University Hamburg Hamburg Germany
| |
Collapse
|
26
|
Lobban KD, Lovegrove BG, Rakotondravony D. The energetics of a Malagasy rodent, Macrotarsomys ingens (Nesomyinae): a test of island and zoogeographical effects on metabolism. J Comp Physiol B 2014; 184:1077-89. [DOI: 10.1007/s00360-014-0853-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/22/2014] [Accepted: 08/05/2014] [Indexed: 11/24/2022]
|
27
|
Torpor is not the only option: seasonal variations of the thermoneutral zone in a small primate. J Comp Physiol B 2014; 184:789-97. [PMID: 24942312 DOI: 10.1007/s00360-014-0834-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 04/30/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
The reddish-gray mouse lemur (Microcebus griseorufus) is one of only a few small mammals inhabiting the spiny forest of southwestern Madagascar. In this study we investigated the physiological adjustments which allow these small primates to persist under the challenging climatic conditions of their habitat. To this end we measured energy expenditure (metabolic rate) and body temperature of 24 naturally acclimatized mouse lemurs, kept in outdoor enclosures, during different seasons (summer, winter, and the transition period between the two seasons). Mouse lemurs displayed two main physiological strategies to compensate seasonal and diurnal fluctuations of ambient temperature. On the one hand, individuals entered hypometabolism with decreasing ambient temperature (T a) during the transition period and winter, enabling them to save up to 21 % energy per day (92 % per hour) compared with the normal resting metabolic rate at comparable T a. On the other hand, euthermic mouse lemurs also showed physiological adjustments to seasonality when resting: the lower critical temperature of the thermoneutral zone decreased from summer to winter by 7.5 °C, which allowed mouse lemurs to keep energy demands constant despite colder T as during winter. In addition, the basal metabolic rate was substantially lowered prior to the winter period, which facilitated accumulation of fat reserves. The combination of physiological modifications during euthermia in addition to hypometabolism, which can be individually adjusted according to external parameters and respective body condition, is important as it allows M. griseorufus to cope with the environmental variability of an energetically challenging habitat.
Collapse
|
28
|
Crowley BE, Rasoazanabary E, Godfrey LR. Stable isotopes complement focal individual observations and confirm dietary variability in reddish-gray mouse lemurs (Microcebusgriseorufus) from southwestern Madagascar. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 155:77-90. [DOI: 10.1002/ajpa.22555] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 05/08/2014] [Accepted: 05/24/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Brooke E. Crowley
- Department of Geology; University of Cincinnati; Cincinnati OH 45221
- Department of Anthropology; University of Cincinnati; Cincinnati OH 45221
| | | | - Laurie R. Godfrey
- Department of Anthropology; University of Massachusetts; Amherst MA 01003
| |
Collapse
|
29
|
Thompson CL, Williams SH, Glander KE, Teaford MF, Vinyard CJ. Body temperature and thermal environment in a generalized arboreal anthropoid, wild mantled howling monkeys (Alouatta palliata). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 154:1-10. [PMID: 24610247 DOI: 10.1002/ajpa.22505] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 02/23/2014] [Indexed: 11/08/2022]
Abstract
Free-ranging primates are confronted with the challenge of maintaining an optimal range of body temperatures within a thermally dynamic environment that changes daily, seasonally, and annually. While many laboratory studies have been conducted on primate thermoregulation, we know comparatively little about the thermal pressures primates face in their natural, evolutionarily relevant environment. Such knowledge is critical to understanding the evolution of thermal adaptations in primates and for comparative evaluation of humans' unique thermal adaptations. We examined temperature and thermal environment in free-ranging, mantled howling monkeys (Alouatta palliata) in a tropical dry forest in Guanacaste, Costa Rica. We recorded subcutaneous (Tsc ) and near-animal ambient temperatures (Ta ) from 11 animals over 1586.5 sample hours during wet and dry seasons. Howlers displayed considerable variation in Tsc , which was largely attributable to circadian effects. Despite significant seasonal changes in the ambient thermal environment, howlers showed relatively little evidence for seasonal changes in Tsc . Howlers experienced warm thermal conditions which led to body cooling relative to the environment, and plateaus in Tsc at increasingly warm Ta . They also frequently faced cool thermal conditions (Ta < Tsc ) in which Tsc was markedly elevated compared with Ta . These data add to a growing body of evidence that non-human primates have more labile body temperatures than humans. Our data additionally support a hypothesis that, despite inhabiting a dry tropical environment, howling monkeys experience both warm and cool thermal pressures. This suggests that thermal challenges may be more prevalent for primates than previously thought, even for species living in nonextreme thermal environments.
Collapse
Affiliation(s)
- Cynthia L Thompson
- Department of Biomedical Sciences, Grand Valley State University, Allendale, MI
| | | | | | | | | |
Collapse
|
30
|
Affiliation(s)
- K. H. Dausmann
- Department of Animal Ecology and Conservation, Biocentre Grindel; University of Hamburg; Hamburg Germany
| |
Collapse
|
31
|
Lovegrove BG, Canale C, Levesque D, Fluch G, Reháková-Petrů M, Ruf T. Are tropical small mammals physiologically vulnerable to Arrhenius effects and climate change? Physiol Biochem Zool 2013; 87:30-45. [PMID: 24457919 DOI: 10.1086/673313] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
There is some urgency in the necessity to incorporate physiological data into mechanistic, trait-based, demographic climate change models. Physiological responses at the individual level provide the mechanistic link between environmental changes and individual performances and hence population dynamics. Here we consider the causal relationship between ambient temperature (Ta) and metabolic rate (MR), namely, the Arrhenius effect, which is directly affected by global warming through increases in average global air temperatures and the increase in the frequency and intensity of extreme climate events. We measured and collated data for several small, free-ranging tropical arboreal mammals and evaluated their vulnerability to Arrhenius effects and putative heat stress associated with climate change. Skin temperatures (Tskin) were obtained from free-ranging tarsiers (Tarsius syrichta) on Bohol Island, Philippines. Core body temperature (Tb) was obtained from the greater hedgehog tenrec (Setifer setosus) and the gray brown mouse lemur (Microcebus ravelobensis) from Ankarafantsika, Madagascar. Tskin for another mouse lemur, Microcebus griseorufus, was obtained from the literature. All four species showed evidence of hyperthermia during the daytime rest phase in the form of either Tskin or Tb that was higher than the normothermic Tb during the nighttime active phase. Potentially, tropical arboreal mammals with the lowest MRs and Tb, such as tarsiers, are the most vulnerable to sustained heat stress because their Tb is already close to Ta. Climate change may involve increases in MRs due to Arrhenius effects, especially during the rest phase or during torpor and hibernation. The most likely outcome of increased Arrhenius effects with climate change will be an increase in energy expenditure at the expense of other critical functions such as reproduction or growth and will thus affect fitness. However, we propose that these hypothetical Arrhenius costs can be, and in some species probably are, offset by the use of hyperthermic daily torpor, that is, hypometabolism at high Ta.
Collapse
Affiliation(s)
- Barry G Lovegrove
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa; 2Department of Integrative Biology and Evolution, Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna 1160, Austria; 3Zoo Decin, Pastýřská stěna, Žižkova 15, Děčín 405 02, Czech Republic; and Tarsius, o.s., Na Pěšině 256, Děčín 405 05, Czech Republic
| | | | | | | | | | | |
Collapse
|
32
|
Crowley BE, Blanco MB, Arrigo-Nelson SJ, Irwin MT. Stable isotopes document resource partitioning and effects of forest disturbance on sympatric cheirogaleid lemurs. Naturwissenschaften 2013; 100:943-56. [DOI: 10.1007/s00114-013-1094-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 08/19/2013] [Accepted: 08/21/2013] [Indexed: 12/25/2022]
|
33
|
Dausmann KH, Wein J, Turner JM, Glos J. Absence of heterothermy in the European red squirrel (Sciurus vulgaris). Mamm Biol 2013. [DOI: 10.1016/j.mambio.2013.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
34
|
|
35
|
Nowack J, Mzilikazi N, Dausmann KH. Torpor as an emergency solution in Galago moholi: heterothermy is triggered by different constraints. J Comp Physiol B 2012; 183:547-56. [DOI: 10.1007/s00360-012-0725-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/17/2012] [Accepted: 11/22/2012] [Indexed: 10/27/2022]
|
36
|
Klopfer PH. Lessons From an Unusual Critter: What Can Unusual Animals Teach Us? Ethology 2012. [DOI: 10.1111/eth.12010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
37
|
Kamilar JM, Muldoon KM, Lehman SM, Herrera JP. Testing Bergmann's rule and the resource seasonality hypothesis in Malagasy primates using GIS-based climate data. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 147:401-8. [PMID: 22271559 DOI: 10.1002/ajpa.22002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 11/22/2011] [Indexed: 11/06/2022]
Abstract
We tested four major hypotheses on the ecological aspects of body mass variation in extant Malagasy strepsirrhines: thermoregulation, resource seasonality/scarcity, resource quality, and primary productivity. These biogeographic hypotheses focus on the ecological aspects of body mass variation, largely ignoring the role of phylogeny for explaining body mass variation within lineages. We tested the independent effects of climate and resource-related variables on variation in body mass among Malagasy primates using recently developed comparative methods that account for phylogenetic history and spatial autocorrelation. We extracted data on lemur body mass and climate variables for a total of 43 species from 39 sites. Climatic data were obtained from the WorldClim database, which is based on climate data from weather stations compiled around the world. Using generalized linear models that incorporate parameters to account for phylogenetic and spatial autocorrelation, we found that diet and climate variables were weak predictors of lemur body mass. Moreover, there was a strong phylogenetic effect relative to the effects of space on lemur body mass in all models. Thus, we failed to find support for any of the four hypotheses on patterns of geography and body mass in extant strepsirrhines. Our results indicate that body mass has been conserved since early in the evolutionary history of each genus, while species diversified into different environmental niches. Our findings are in contrast to some previous studies that have suggested resource and climate related effects on body mass, though these studies have examined this question at different taxonomic and/or geographic scales.
Collapse
Affiliation(s)
- Jason M Kamilar
- Department of Anthropology, Yale University, New Haven, CT; Department of Anatomy, Midwestern University, Glendale, AZ, USA.
| | | | | | | |
Collapse
|
38
|
Rakotondranary SJ, Ganzhorn JU. Habitat separation of sympatric Microcebus spp. in the dry spiny forest of south-eastern Madagascar. ACTA ACUST UNITED AC 2012; 82:212-23. [PMID: 22236872 DOI: 10.1159/000334816] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 10/26/2011] [Indexed: 01/16/2023]
Abstract
We investigated whether or not habitat structure contributes to the separation of two sister species of lemurs and their hybrids. For this, we studied Microcebus murinus and M. griseorufus along a continuous vegetation gradient where populations of the two species occur in sympatry or in allopatry. In allopatry, the two species are generalists without any sign of microhabitat selectivity. In sympatry, both species differed significantly and discriminated against certain habitat structures: M. murinus was found in microhabitats with larger trees than average while M. griseorufus utilized microhabitats with smaller trees. Hybrids between the two species did not show any significant discrimination for or against microhabitat structure and did not differ in their habitat utilization from either parent species. Both species can go into torpor and hibernation. M. griseorufus is seen more frequently during the cool dry season than M. murinus. We assume that M. murinus goes into extended torpor or hibernation more frequently than M. griseorufus. We interpret the different occurrence of large-sized trees in microhabitats of M. murinus as a prerequisite for M. murinus to be able to spend extended periods of time in tree holes that are isolated and allow hibernation at reduced temperature levels.
Collapse
Affiliation(s)
- S Jacques Rakotondranary
- Department of Animal Ecology and Conservation, University of Hamburg, Biozentrum Grindel, Hamburg, Germany.
| | | |
Collapse
|
39
|
Turner JM, Warnecke L, Körtner G, Geiser F. Opportunistic hibernation by a free-ranging marsupial. J Zool (1987) 2011. [DOI: 10.1111/j.1469-7998.2011.00877.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. M. Turner
- Department of Zoology; Centre for Behavioural and Physiological Ecology; University of New England; Armidale; NSW; Australia
| | - L. Warnecke
- Department of Zoology; Centre for Behavioural and Physiological Ecology; University of New England; Armidale; NSW; Australia
| | - G. Körtner
- Department of Zoology; Centre for Behavioural and Physiological Ecology; University of New England; Armidale; NSW; Australia
| | - F. Geiser
- Department of Zoology; Centre for Behavioural and Physiological Ecology; University of New England; Armidale; NSW; Australia
| |
Collapse
|
40
|
Rakotondranary SJ, Struck U, Knoblauch C, Ganzhorn JU. Regional, seasonal and interspecific variation in 15N and 13C in sympatric mouse lemurs. Naturwissenschaften 2011; 98:909-17. [PMID: 21881908 DOI: 10.1007/s00114-011-0840-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 08/17/2011] [Accepted: 08/19/2011] [Indexed: 11/30/2022]
Abstract
Madagascar provides some of the rare examples where two or more primate species of the same genus and with seemingly identical niche requirements occur in sympatry. If congeneric primate species co-occur in other parts of the world, they differ in size in a way that is consistent with Hutchinson's rule for coexisting species, or they occupy different ecological niches. In some areas of Madagascar, mouse lemurs do not follow these "rules" and thus seem to violate one of the principles of community ecology. In order to understand the mechanisms that allow coexistence of sympatric congeneric species without obvious niche differentiation, we studied food composition of two identical sized omnivorous mouse lemur species, Microcebus griseorufus and M. murinus with the help of stable isotope analyses (δ(15)N and δ(13)C). The two species are closely related sister species. During the rich season, when food seems abundant, the two species do not differ in their nitrogen isotope composition, indicating that the two species occupy the same trophic level. But they differ in their δ(13)C values, indicating that M. griseorufus feeds more on C(4) and CAM (Crassulacean-acid-metabolism) plants than M. murinus. During the lean season, M. murinus has lower δ(15)N values, indicating that the two species feed at different trophic levels during times of food shortage. Hybrids between the two species showed intermediate food composition. The results reflect subtle differences in foraging or metabolic adaptations that are difficult to quantify by traditional observations but that represent possibilities to allow coexistence of species.
Collapse
Affiliation(s)
- S Jacques Rakotondranary
- Department of Animal Ecology and Conservation, University of Hamburg, Biozentrum Grindel, Martin-Luther-King Platz 3, 20146, Hamburg, Germany.
| | | | | | | |
Collapse
|
41
|
Seasonal Changes in Feeding Ecology and Activity Patterns of Two Sympatric Mouse Lemur Species, the Gray Mouse Lemur (Microcebus murinus) and the Golden-brown Mouse Lemur (M. ravelobensis), in Northwestern Madagascar. INT J PRIMATOL 2011. [DOI: 10.1007/s10764-010-9488-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
42
|
Blanco MB, Rahalinarivo V. First direct evidence of hibernation in an eastern dwarf lemur species (Cheirogaleus crossleyi) from the high-altitude forest of Tsinjoarivo, central-eastern Madagascar. Naturwissenschaften 2010; 97:945-50. [PMID: 20835697 DOI: 10.1007/s00114-010-0707-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/02/2010] [Accepted: 08/04/2010] [Indexed: 12/26/2022]
Abstract
The nocturnal dwarf lemurs of Madagascar (genus Cheirogaleus) are the only primates known to be obligate hibernators. Although the physiology of hibernation has been studied widely in the western, small-bodied species, Cheirogaleus medius, no direct evidence of hibernation, i.e., body temperature recordings, has been reported for any of the three recognized eastern dwarf lemur species. We present skin temperature data collected by external collar transmitters from two eastern dwarf lemur individuals (Cheirogaleus crossleyi) captured in the high-altitude forest of Tsinjoarivo, central-eastern Madagascar. Our study species is larger in body size than western dwarf lemurs and inhabits much colder environments. We present the first evidence of hibernation in an eastern dwarf lemur species, and we compare the results with data available for the western species. Although the hibernation period is shorter in dwarf lemurs from Tsinjoarivo, minimum body temperatures are lower than those reported for C. medius. Both individuals at Tsinjoarivo showed limited passive and extended deep hibernation during which they did not track ambient temperature as observed in most western dwarf lemurs. Because ambient temperatures at Tsinjoarivo never exceed 30°C, dwarf lemurs have to experience arousals to maintain homeostasis during periods of hibernation. We show that large dwarf lemurs (>400 g) are capable of undergoing deep hibernation and suggest that cold, high-altitude forests may render hibernation highly advantageous during periods of food scarcity. This study has implications for understanding the physiology of hibernation in small-bodied lemurs.
Collapse
Affiliation(s)
- Marina B Blanco
- Department of Anthropology, University of Massachusetts, 240 Hicks Way, Amherst, MA 01003, USA.
| | | |
Collapse
|
43
|
Kobbe S, Ganzhorn JU, Dausmann KH. Extreme individual flexibility of heterothermy in free-ranging Malagasy mouse lemurs (Microcebus griseorufus). J Comp Physiol B 2010; 181:165-73. [PMID: 20717683 DOI: 10.1007/s00360-010-0507-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 06/23/2010] [Accepted: 07/29/2010] [Indexed: 11/30/2022]
Abstract
Flexibility in physiological processes is essential to adequately respond to changes in environmental conditions. Madagascar is a particularly challenging environment because climatic conditions seem less predictable than in comparative ecosystems in other parts of the world. We used the reddish-gray mouse lemur (Microcebus griseorufus) from the most unpredictable environment in Madagascar as a model to investigate the flexibility of energy saving strategies to cope with the unpredictability of their habitat. For this we measured T (sk) of free-ranging mouse lemurs throughout the year using temperature data loggers. M. griseorufus showed a very strong seasonal as well as an individual flexibility in thermoregulation. During the rainy season all M. griseorufus remained normothermic. At the beginning of the dry season individuals started to exhibit different energy saving strategies: irregular short torpor bouts, regular daily torpor, prolonged torpor of a few days, and hibernation over several weeks. The accumulation of sufficient seasonal body fat was the crucial factor determining the thermal behavior of individuals. The observed intraspecific and sex independent variation in thermoregulatory patterns within one population inhabiting the same small geographical area is exceptional and gives M. griseorufus the ability to respond to current environmental as well as individual conditions. This thermal plasticity might be seen as a key to success and survival for M. griseorufus in an extremely unpredictable environment.
Collapse
Affiliation(s)
- Susanne Kobbe
- Department of Animal Ecology and Conservation, Hamburg University, Biozentrum Grindel, Martin-Luther-King Platz 3, 20146 Hamburg, Germany.
| | | | | |
Collapse
|
44
|
Génin F. Who sleeps with whom? Sleeping association and socio-territoriality inMicrocebus griseorufus. J Mammal 2010. [DOI: 10.1644/09-mamm-a-239.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
45
|
Nowack J, Mzilikazi N, Dausmann KH. Torpor on demand: heterothermy in the non-lemur primate Galago moholi. PLoS One 2010; 5:e10797. [PMID: 20520735 PMCID: PMC2875402 DOI: 10.1371/journal.pone.0010797] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 05/03/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hibernation and daily torpor are energy- and water-saving adaptations employed to survive unfavourable periods mostly in temperate and arctic environments, but also in tropical and arid climates. Heterothermy has been found in a number of mammalian orders, but within the primates so far it seems to be restricted to one family of Malagasy lemurs. As currently there is no evidence of heterothermy of a primate outside of Madagascar, the aim of our study was to investigate whether small primates from mainland Africa are indeed always homeothermic despite pronounced seasonal changes in weather and food availability. METHODOLOGY/PRINCIPAL FINDINGS One of the nearest relatives of Malagasy lemurs, the African lesser bushbaby, Galago moholi, which inhabits a highly seasonal habitat with a hot wet-season and a cold dry-season with lower food abundance, was investigated to determine whether it is capable of heterothermy. We measured skin temperature of free-ranging individuals throughout the cool dry season using temperature-sensitive collars as well as metabolic rate in captured individuals. Torpor was employed by 15% of 20 animals. Only one of these animals displayed heterothermy in response to natural availability of food and water, whereas the other animals became torpid without access to food and water. CONCLUSIONS/SIGNIFICANCE Our results show that G. moholi are physiologically capable of employing torpor. However they do not use it as a routine behaviour, but only under adverse conditions. This reluctance is presumably a result of conflicting selective pressures for energy savings versus other ecological and evolutionary forces, such as reproduction or territory defence. Our results support the view that heterothermy in primates evolved before the division of African and Malagasy Strepsirhini, with the possible implication that more primate species than previously thought might still have the potential to call upon this possibility, if the situation necessitates it.
Collapse
Affiliation(s)
- Julia Nowack
- Department of Animal Ecology and Conservation, Biocentre Grindel, University of Hamburg, Hamburg, Germany.
| | | | | |
Collapse
|
46
|
|