ABSTRACT Many birds and mammals drastically reduce their energy expenditure during times of cold exposure, food shortage, or drought, by temporarily abandoning euthermia, i.e. the maintenance high body temperatures. Traditionally, two different types heterothermy, hypometabolic states associated with low temperature (torpor), have been distinguished: daily torpor, which lasts less than 24 h is accompanied continued foraging, versus hibernation, torpor bouts lasting consecutive days to...

Hibernation and daily torpor are usually considered to be two distinct patterns of heterothermia. In the present comparison we evaluated (1) whether physiological variables from 104 avian mammalian species warrant distinction between hibernation as different states (2), if so, this is best based on maximum bout duration, minimum body temperature (Tb), metabolic rate during torpor, or reduction expressed percentage basal metabolism (BMR). Initially, animals were grouped into displaying either...

Summary In terrestrial ecosystems many species show large population fluctuations caused by pulsed resources, such as mast seeding. A prime example of a mammal strongly affected seeding trees is the wild boar Sus scrofa , that has become pest in parts world. We investigated dynamics to assist development effective management strategies for this and possibly other resource consumers. analysed published vital rates using Leslie matrix projection models elasticity analysis. Models were based on...

Survival probability is predicted to underlie the evolution of life histories along a slow–fast continuum. Hibernation allows diverse range small mammals exhibit seasonal dormancy, which might increase survival and consequently be associated with relatively slow histories. We used phylogenetically informed GLS models test for an effect hibernation on annual survival, key attributes among mammals. Monthly was in most cases higher during compared active season, probably because inactivity...

Abstract This paper investigates the utility of Lomb–Scargle periodogram for analysis biological rhythms. method is particularly suited to detect periodic components in unequally sampled time-series and data sets with missing values, but restricts all calculations actually measured values. The Lomb-Scargle was tested on both real simulated even uneven sampling, compared a standard biomedical rhythm research, Chi-square periodogram. Results indicate that algorithm shows clearly better...

Evidence has recently begun to accumulate that photoperiodic responses of mammals and birds may affect the control energy balance thermoregulation. Exposure short photoperiod can lower set point for body temperature regulation in mammals, as well voluntarily selected ectothermic lizards. This decrease is accompanied by a reorganization circadian or ultradian rhythms temperature, particularly an increase periods spent at rest with minimum temperatures. Short also used environmental cue...

Summary Hibernation is the most effective means for energy conservation during winter in mammals. The drawbacks of deep and prolonged torpor include reduced immunocompetence, consequently, hibernators should be selected to minimize expression when climatic conditions or availability (e.g. food fat stores) permit. Therefore, it seems surprising that some employ extraordinary long hibernation seasons, lasting well beyond periods with unfavourable conditions. Because their extended use torpor,...

Abstract This study addresses the correlation of retinal topography with factors such as visual environment, life style, and behavior for a major mammalian group, artiodactyls. To provide broader basis semiquantitative comparison, short‐wavelength‐sensitive (S)‐ middle‐to‐long‐wavelength‐sensitive (M)‐opsin cone receptor populations from 25 species five artiodactyl families African elephant were labeled sampled. The resulting topographic maps analyzed respect to position extension...

Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, possibly population-specific responses still sparse. We investigated large-scale long-term effects climate local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that increases across Europe are strongly associated with increasingly mild winters, yet region-specific threshold temperatures for onset exponential growth....

1. The extent to which free-ranging large north-temperate mammals seasonally adjust thermoregulation and their energy expenditure under fully natural conditions are unknown. 2. Therefore, using telemetry we measured the heart rate (as a proxy for metabolic rate), rumen temperature (Tr) locomotor activity (LA) over 2 years 20 Alpine ibex (Capra ibex) living at high altitudes in Alps. 3. Ibex showed strong seasonal changes mean daily with winter nadir of about 60% below summer peak. Only 40%...

We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species rodents hibernating either 3 or 14°C. Our data show that hibernators kept warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals colder temperature. suggest high-energy demand frequent arousals is counteracted a lower differential between torpid and euthermic body length restored during when returned to normothermic values. Taken...

Herbivores of temperate and arctic zones are confronted during winter with harsh climatic conditions nutritional shortness. It is still not fully understood how large ungulates cope this twofold challenge. We found that red deer, similar to many other northern ungulates, show seasonal fluctuations metabolic rate, as indicated by heart a 60% reduction at the nadir compared summer peak. A previously unknown mechanism energy conservation, i.e., nocturnal hypometabolism associated peripheral...

Many large mammals show pronounced seasonal fluctuations of metabolic rate (MR). It has been argued, based on studies in ruminants, that this variation merely results from different levels locomotor activity (LA), and heat increment feeding (HI). However, a recent study red deer (Cervus elaphus) identified previously unknown mechanism ungulates--nocturnal hypometabolism--that contributed significantly to reduced energy expenditure, mainly during late winter. The relative contribution these...

Abstract We investigated the influence of ambient temperature (T a ) and food availability on seasonal timing extent physiological responses to short photoperiod (SP), in particular daily torpor, Djungarian hamsters ( Phodopus sungorus ). Exposure cold = 5°C), relative warm T (23°C), resulted in:(1)a significant advance P < 0.05) first occurrence torpor among cold‐exposed (days 52–97 vs. days 83–99 SP); (2) higher 0.01) incidence (48% 20% torpid animals/day);(3) degree molt into winter...

Edible dormice (Glis glis) reproduce in years with beech mast seeding, but entire populations may skip reproduction when tree seeds, a major food resource of this small hibernator, are absent. We tested the hypothesis that year-to-year variability reproductive effort caused by breeding strategy should lead to detectable differences yearly survival rates. Therefore, we analyzed capture–recapture data from animals occupying nest boxes, collected over nine at two study sites Germany. Among...

Red deer, Cervus elaphus, like other temperate-zone animals, show a large seasonal fluctuation in energy intake and expenditure. Many phenotypic adjustments are coordinated by endogenous signals entrained to the photoperiod. The cues determining variation resting metabolism of ungulates remain equivocal, however, largely because confounding effects food thus heat increment feeding. To distinguish environmental on metabolism, we subjected 15 female red deer two feeding treatments, 80%...

Polyunsaturated fatty acids (PUFA) have a multitude of health effects. Their incorporation into membrane phospholipids (PL) is generally believed to depend directly on dietary influx. PL influence transmembrane protein activity and thus can compensate temperature effects; e.g. n-6 PUFA are thought stabilize heart function at low body (Tb), whereas long chain (>C18) n-3 may boost oxidative capacity. We found substantial remodeling membranes in free-living alpine marmots which was largely...

Small hibernating rodents have greater maximum lifespans and hence appear to age more slowly than similar-sized non-hibernators. We tested for a direct effect of hibernation on somatic maintenance ageing by measuring seasonal changes in relative telomere length (RTL) the edible dormouse Glis glis. Average RTL our population did not change significantly over season, regression model explaining individual variation post-hibernation suggested significant negative reduction body mass inactive...