不同海拔地区高原鼠兔探究性和静止代谢率的差异

环境的差异影响动物种群生活史对策的进化。对地理分布范围广的物种而言,栖息地环境差异大,不同种群的生活史对策亦存在显著差异。个性特征作为生活史的一部分,反映了动物对环境的适应模式。前期研究表明,不同海拔区域的高原鼠兔的生活史对策存在显著差异,然而,其个性特征及与能量代谢的关联性是否也存在差异,目前尚不清楚。2018年9-10月,分别在海拔3268 m的贵南县和3980 m的玛沁县测定当地高原鼠兔的探究性与静止代谢率。结果发现,高海拔雄性高原鼠兔的探究性显著低于低海拔雄性个体;高海拔雌性高原鼠兔体重矫正静止代谢率显著高于低海拔雌性个体。高海拔地区,雌性高原鼠兔的探究性和体重矫正静止代谢率呈显著正相关,雄性高原鼠兔的探究性和体重呈显著负相关;低海拔地区,高原鼠兔的探究性和体重矫正静止代谢率或体重之间均无显著相关性。该结果 表明,调整个性特征和能量代谢及其两者的关联性也是高原鼠兔适应不同海拔栖息地环境差异的生活史对策之一。     

广东罗坑自然保护区鳄蜥的体温调节及静止代谢率的热依赖性

探讨鳄蜥（Shinisaurus crocodilurus）的体温调节和静止代谢率及其热依赖性特征,测定了在自然和实验室条件下的环境温度、鳄蜥体温以及静止代谢率（RMR）等热生物学指标。结果显示：在自然条件下,鳄蜥的野外活动体温（Th）稍高于基质温度（Tc）和空气温度（Td）并与后二者呈正相关关系（Tb=11．65＋0．47Tc,r^2=0．34,F1.75=39．11,P〈0．0001;Tb=11．61＋0．46Td,r^2=0．56,F1.75=96．56,P〈0．0001）。鳄蜥在野外的活动体温存在明显的月份间差异,但无性别及年龄上的差异。环境温度为15℃-30℃的实验条件下,鳄蜥的静止体温（Tb）与环境温度（Ta）呈正相关关系：Tb=12．450＋0．5641Ta（F1.110=11．34,r^2=0．997,P〈0．001）;在缺乏温度梯度的环境中,尽管鳄蜥的体温、空气温度和基质温度都有显著的昼夜差异,但体温、空气温度和基质温度的日平均温度之间无显著差异。鳄蜥的RMR不存在雌雄个体间的差异,并与环境温度呈正相关关系。分析显示鳄蜥的体温既有行为调节也有生理调节,其体温调节及RMR符合变温动物的热生物学特征,但是相对于其他活动较多的蜥蜴而言,鳄蜥的生理调节能力较强,这可能与其活动时间分配中静栖占绝大部分的行为特点是相适应的[动物学报54（6）：964-971,2008]。     

Variations in resting metabolic rates of men in Antarctica

The resting metabolic rates (RMR) of 6 men was determined monthly for 12 consecutive months, at Rothera Base, Antarctica (67 degrees 34'S, 68 degrees 07'W). Body weight and body composition were also recorded. Metabolic rates were within the range of those found in past polar studies, and of young men in the UK, but varied considerably from month to month. The RMR had a mean range of 30% (p less than 0.01), with individual ranges of up to 38%. Mean RMR was high in spring, summer and autumn, and low in winter. While these patterns appeared to be associated with a well defined annual cycle of activity, variations could not be correlated with periods of intense activity, individually or for the group.     

An evolutionary life-history framework for understanding sex differences in human mortality rates

Sex differences in mortality rates stem from genetic, physiological, behavioral, and social causes that are best understood when integrated in an evolutionary life history framework. This paper investigates the Male-to-Female Mortality Ratio (M:F MR) from external and internal causes and across contexts to illustrate how sex differences shaped by sexual selection interact with the environment to yield a pattern with some consistency, but also with expected variations due to socioeconomic and other factors. Daniel J. Kruger earned his Ph.D. in Social Psychology at Loyola University Chicago and is currently an Assistant Research Scientist at the University of Michigan. His evolutionary research interests include altruism, cooperation, competition, risk, life history, mortality patterns, mating strategies, and applications for social and ecological sustainability. Randolph M. Nesse is Professor of Psychiatry, Professor of Psychology, and Research Professor at the Institute for Social Research at the University of Michigan, where he directs the Evolution and Human Adaptation Program. His research interests are focused on Darwinian medicine, especially the origins of depression and other forms of psychopathology.     

Accuracy of predicted resting metabolic rate and relationship between resting metabolic rate and cardiorespiratory fitness in obese men

[Purpose]

The purpose of this study is to examine that not only the relationship of the resting metabolic rate (RMR) and cardiorespiratory fitness(VO2peak), but also the comparison between measured and predicted results of RMR in obese men.

[Methods]

60 obese men (body fat>32%) were recruited for this study. They did not participate in regular exercising programs at least 6 months. The RMR was measured with indirect calorimetry and predicted RMR using Herris-Benedicte equation. The cardiorespiratory fitness was determined by directly measuring the oxygen consumption (VO2peak) during the exercise on the treadmill.

[Results]

The significance for the difference between the measured results and predicted result of RMR were tested by paired t-test. Correlation of measured date was obtained by Pearson correlation coefficient. The value of predicted RMR and measured RMR were significantly different in these obese subjects. (p < 0.001). The difference between RMR cardiorespiratory fitness and cardiorespiratory fitness showed significant correlation (r=0.67, p < 0.05).

[Conclusion]

The current formulas of predicted RMR have limited the evaluation of measured RMR for Korean obese men. Therefore, this study suggests that new formula should be designed for Korean in order to obtain more accurate results in obese.     

Heritability of flight and resting metabolic rates in the Glanville fritillary butterfly

Dispersal capacity is a key life‐history trait especially in species inhabiting fragmented landscapes. Evolutionary models predict that, given sufficient heritable variation, dispersal rate responds to natural selection imposed by habitat loss and fragmentation. Here, we estimate phenotypic variance components and heritability of flight and resting metabolic rates (RMRs) in an ecological model species, the Glanville fritillary butterfly, in which flight metabolic rate (FMR) is known to correlate strongly with dispersal rate. We modelled a two‐generation pedigree with the animal model to distinguish additive genetic variance from maternal and common environmental effects. The results show that FMR is significantly heritable, with additive genetic variance accounting for about 40% of total phenotypic variance; thus, FMR has the potential to respond to selection on dispersal capacity. Maternal influences on flight metabolism were negligible. Heritability of flight metabolism was context dependent, as in stressful thermal conditions, environmentally induced variation dominated over additive genetic effects. There was no heritability in RMR, which was instead strongly influenced by maternal effects. This study contributes to a mechanistic understanding of the evolution of dispersal‐related traits, a pressing question in view of the challenges posed to many species by changing climate and fragmentation of natural habitats.     

Defects in resting metabolic rates and mitochondrial respiration in Kwashiorkor and dietary obese rats

Summary Resting metabolic rates have been measured and compared with hepatic mitochondrial respiration in Kwashiorkor and diet-induced obese weaned rats. In Kwashiorkor, resting metabolic rate was 21% lower than the value of controls, while that of the obese rats was 14% higher than in control animals. The resting metabolic rate for Kwashiorkor animals was 50% of the predicted basal metabolic rate (BMR), whereas that of the obese rats was 23% higher than the predicted BMR. The mitochondrial oxygen consumption patterns, using malate plus glutamate or succinate as respiratory substrates, revealed that the resting respiration (state 4) was 23.9% higher in Kwashiorkor and 29.1% higher in obese animals, while the active (state 3) respiration was 34.8% lower in Kwashiorkor and 43.3% lower in obese rats compared to controls. The respiratory control ratios (RCR) were 51.1% and 43.8% in Kwashiorkor and obese rats, respectively, relative to the values in control rats. It is concluded from these studies that Kwashiorkor disease and diet-induced obesity appear to interfere with oxygen utilization at the level of state 3 mitochondrial respiration, which is markedly decreased when compared to the values for control animals.Abbreviations BMR basal metabolic rate - CPD commercially produced diet - KWD low protein, high carbohydrate diet - OBD high fat diet - PEM protein-energy malnutrition - RCR respiratory control ratios Present address: Department of Biochemistry, University of Nairobi, P.O. Box 30197, Nairobi, Kenya     

A meta-analysis of the effects of exercise and/or dietary restriction on resting metabolic rate

A meta-analysis was used to examine the independent and interactive effects of dietary restriction, endurance exercise training and gender on resting metabolic rate (RMR). Sixty different group means (covering 650 subjects) were identified from the scientific literature and subjected to meta-analysis techniques. Collectively (i.e., all groups combined), body weight loss was greater (P < 0.05) for men ( 18 kg) than for women ( 12 kg). There were no statistically significant exercise training or gender effects on RMR during weight loss. Collectively (i.e., all groups combined), dietary restriction resulted in a – 0.59 kJ min^–1 ( – 12%) decrease in RMR (P < 0.05). When normalized to body weight, RMR was reduced by less than 2% (P < 0.05). These data suggest that exercise training does not differentially affect RMR during diet-induced weight loss. In addition, decreases in resting metabolism appear to be proportional to the loss of the metabolically active tissue.     

Seasonal variations in the metabolic rates of zooplankton populations in a Thames Valley reservoir

Measurements of metabolic rates of natural populations of zooplankton were made using a closed bottle technique in situ. Results showed a marked seasonality inexplicable in terms of simple temperature functions. For this cladoceran dominated zooplankton, seasonal variations in metabolic response are attributed to a degree of temperature acclimation, to changes in the size structure and species composition of the populations and seasonal variations in food sources.     

Mating system in the tarantula spider Eupalaestrus weijenberghi (Thorell, 1894): evidences of monandry and polygyny

The road tarantula Eupalaestrus weijenberghi shows a strongly female-biased sex ratio since adult females live several years while adult males live only for 2 months. In this scenario selective males could be expected. However, several factors such as the rates of reproduction of each sex, degree of sexual selectivity and synchronicity of female receptiveness determine the operational sexual ratio and mating system of the species. Our objective was to determine the mating rates and mating tactics for females and males of E. weijenberghi and their variation throughout the reproductive period. Four hundred sexual encounters among 20 females and 20 males in all possible pair-wise combinations were carried out during 29 days, a brief but intense experimental period, as it also occurs in the field. Mating success differed strongly between sexes. Females mated once: five females mated at the first attempt, eight initially rejected males and copulated in subsequent attempts. Half of the males did not copulate and the others copulated 1-3 times. Mated females actively rejected males. Results indicate a mating system with monogamous females and polygamous males. Not all the females were receptive in every reproductive season. We suggest that female monogamy drastically affects the operational sex ratio, since several females were unreceptive after a single copulation, directly diminishing the male potential reproductive rate. This is the first experimental approach to estimate tarantula mating systems, their determinants and the consequences of the strategies shown by each sex.     

Sex differences in metabolic rates in field crickets and their dipteran parasitoids

Sex differences in metabolic rate (MR) can result from dimorphism in the performance of energetically demanding activities. Male crickets (Teleogryllus oceanicus) engage in costly calling and aggressive activity not performed by females. Consistent with this difference, we found higher maximal MR, factorial scope, and fat content in males than females. T. oceanicus song is also costly because it attracts the parasitoid fly Ormia ochracea. Parasitized crickets had reduced maximal MR consistent with a metabolic cost to harboring larvae. This cost was greater for females, either because females invest more heavily into reproduction at the expense of metabolic capacity, or because males are under stronger selection to respond to infection. Little is known about O. ochracea outside of its auditory system and parasitic lifestyle. We observed greater resting MR in male flies, possibly reflecting a sex difference in the requirement for metabolic power output, because male flies perform potentially costly mating behavior not seen in females. We found a positive relationship between larval density within a cricket and pupal resting MR, suggesting that crickets in good condition are able to both harbor more larvae and produce larvae with higher resting MR. These results reveal a complex interplay between the metabolism of crickets and their fly parasitoids.Communicated by G. Heldmaier     

Immunocompetence and high metabolic rates enhance overwinter survival in the root vole,Microtus oeconomus

Despite its presumed significance, the association between immune defence, energy expenditures and overwinter survival is rarely studied. We analysed individual variation in immunocompetence quantified as neutrophil-to-lymphocyte ratio (N/L), total white blood cells (WBC) and natural antibody levels, along with resting (RMR) and peak metabolic rates (PMR) and mortality during three consecutive winter seasons in a natural population of the root vole, Microtus oeconomus. In early winter, WBC count was negatively correlated with RMR, whereas N/L ratio was negatively correlated with swim-elicited PMR. We suggest that while the first correlation reflected the trade-off between energy allocation in immunocompetence and other metabolically demanding processes, the latter correlation stemmed from stress-induced immunosuppression elicited by the necessity to cope with swimming in frequently flooded habitat. In addition, the analysis carried out during the first year of study characterized by a high population density and prevalence of infestation with a blood parasite—Babesia spp., showed that its intensity was inversely correlated with the N/L ratio. In summary, our results suggest that elevated N/L ratio increases the winter survival of free-ranging rodents by increasing their ability to cope with parasitic infections.     

The postabsorptive and postprandial metabolic rates of praying mantises: Comparisons across species,body masses,and meal sizes

The metabolic rate of an animal affects the amount of energy available for its growth, activity and reproduction and, ultimately, shapes how energy and nutrients flow through ecosystems. Standard metabolic rate (SMR; when animals are post-absorptive and at rest) and specific dynamic action (SDA; the cost of digesting and processing food) are two major components of animal metabolism. SMR has been studied in hundreds of species of insects, but very little is known about the SMR of praying mantises. We measured the rates of CO₂ production as a proxy for metabolic rate and tested the prediction that the SMR of mantises more closely resembles the low SMR of spiders – a characteristic generally believed to be related to their sit-and-wait foraging strategy. Although few studies have examined SDA in insects we also tested the prediction that mantises would exhibit comparatively large SDA responses characteristic of other types of predators (e.g., snakes) known to consume enormous, protein-rich meals. The SMR of the mantises was positively correlated with body mass and did not differ among the four species we examined. Their SMR was best described by the equation μW = 1526 * g^0.745 and was not significantly different from that predicted by the standard ‘insect-curve’; but it was significantly higher than that of spiders to which mantises are ecologically more similar than other insects. Mantises consumed meals as large as 138% of their body mass and within 6–12 h of feeding and their metabolic rates doubled before gradually returning to prefeeding rates over the subsequent four days. We found that the SDA responses were isometrically correlated with meal size and the relative cost of digestion was 38% of the energy in each meal. We conclude that mantises provide a promising model to investigate nutritional physiology of insect predators as well as nutrient cycling within their ecological communities.     

Compensation in resting metabolism for experimentally increased activity

To study zebra finch allocation of energy to day and night at two different workloads, we assessed the daily energy turnover from: (1) metabolizable energy of the food, and (2) doubly-labeled water. In both experiments we imposed two levels of activity on captive zebra finches (Taeniopygia guttata), by applying different computer-controlled workload schedules. A low workload required 20 hops, and a high workload 40 hops to obtain 10 s access to food. In experiment 1, we further measured nocturnal energy expenditure by overnight oxygen consumption. From experiment 2 we derived an estimate of the costs of hopping activity, from inter-individual association of daily amount of hopping and daily energy expenditure. Surprisingly, the daily energy budget was, on average, reduced slightly when birds were subjected to a high workload. Since hopping activity was 50% higher during the high workload than during the low workload, the birds apparently compensated, even over-compensated, for the increased energetic demands of activity. Nocturnal energy expenditure was indeed reduced for the high workload, which was largely due to a reduction in resting metabolic rate. Economizing on energy was more than could have been accomplished by a reduction in mass alone, and we discuss the occurrence and potential mechanisms of physiological compensation. The amount of energy saved during the night did account for part of the total amount of energy saved. We surmise that the strategy of energetic compensation observed during the night was extended into the inactive hours of the day. Accepted: 10 July 1998     

Sex differences in political leadership in an egalitarian society

We test the contribution of sex differences in physical formidability, education, and cooperation to the acquisition of political leadership in a small-scale society. Among forager-farmers from the Bolivian Amazon, we find that men are more likely to exercise different forms of political leadership, including verbal influence during community meetings, coordination of community projects, and dispute resolution. We show that these differences in leadership are not due to gender per se but are associated with men's greater number of cooperation partners, greater access to schooling, and greater body size and physical strength. Men's advantage in cooperation partner number is tied to their participation in larger groups and to the opportunity costs of women's intrahousehold labor. We argue these results highlight the mutual influence of sexual selection and the sexual division of labor in shaping how women and men acquire leadership.     

Predation promotes survival of beetles with lower resting metabolic rates

The energetic definition of fitness predicts that natural selection will maximize the residual energy available for growth and reproduction suggesting that energy metabolism might be a target of selection. In this experimental study, we investigated whether female and male yellow mealworm beetles, Tenebrio molitor L. (Coleoptera: Tenebrionidae), differ in their hiding behaviour, individual response latency time, and duration of immobility to treatments mimicking an approaching predation threat. We experimentally tested whether consistently repeatable anti‐predatory responses and resting metabolic rates (RMR) correlated with survival rates of individuals exposed to a nocturnal predator, the brown rat, Rattus norvegicus (Berkenhout) (Rodentia: Muridae). Resting metabolic rate was part of a syndrome involving anti‐predator behaviour. Individuals with lower RMR concealed themselves against predators in substrate more successfully than individuals with higher RMR, and hiding was associated with longer periods of immobility. Ultimately, mortality was higher in the high‐RMR beetles compared to the low‐RMR beetles. Our results provide direct evidence of natural selection against mobility, i.e., for reduced RMR in T. molitor beetles.     

A comparison of methods for fitting allometric equations to field metabolic rates of animals

We re-examined data for field metabolic rates of varanid lizards and marsupial mammals to illustrate how different procedures for fitting the allometric equation can lead to very different estimates for the allometric coefficient and exponent. A two-parameter power function was obtained in each case by the traditional method of back-transformation from a straight line fitted to logarithms of the data. Another two-parameter power function was then generated for each data-set by non-linear regression on values in the original arithmetic scale. Allometric equations obtained by non-linear regression described the metabolic rates of all animals in the samples. Equations estimated by back-transformation from logarithms, on the other hand, described the metabolic rates of small species but not large ones. Thus, allometric equations estimated in the traditional way for field metabolic rates of varanids and marsupials do not have general importance because they do not characterize rates for species spanning the full range in body size. Logarithmic transformation of predictor and response variables creates new distributions that may enable investigators to perform statistical analyses in compliance with assumptions underlying the tests. However, statistical models fitted to transformations should not be used to estimate parameters of equations in the arithmetic domain because such equations may be seriously biased and misleading. Allometric analyses should be performed on values expressed in the original scale, if possible, because this is the scale of interest.     

Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae,Mygalomorphae, Theraphosidae) within the United States

This systematic study documents the taxonomy, diversity, and distribution of the tarantula spider genus Aphonopelma Pocock, 1901 within the United States. By employing phylogenomic, morphological, and geospatial data, we evaluated all 55 nominal species in the United States to examine the evolutionary history of Aphonopelma and the group’s taxonomy by implementing an integrative approach to species delimitation. Based on our analyses, we now recognize only 29 distinct species in the United States. We propose 33 new synonymies (Aphonopelma apacheum, Aphonopelma minchi, Aphonopelma rothi, Aphonopelma schmidti, Aphonopelma stahnkei = Aphonopelma chalcodes; Aphonopelma arnoldi = Aphonopelma armada; Aphonopelma behlei, Aphonopelma vogelae = Aphonopelma marxi; Aphonopelma breenei = Aphonopelma anax; Aphonopelma chambersi, Aphonopelma clarum, Aphonopelma cryptethum, Aphonopelma sandersoni, Aphonopelma sullivani = Aphonopelma eutylenum; Aphonopelma clarki, Aphonopelma coloradanum, Aphonopelma echinum, Aphonopelma gurleyi, Aphonopelma harlingenum, Aphonopelma odelli, Aphonopelma waconum, Aphonopelma wichitanum = Aphonopelma hentzi; Aphonopelma heterops = Aphonopelma moderatum; Aphonopelma jungi, Aphonopelma punzoi = Aphonopelma vorhiesi; Aphonopelma brunnius, Aphonopelma chamberlini, Aphonopelma iviei, Aphonopelma lithodomum, Aphonopelma smithi, Aphonopelma zionis = Aphonopelma iodius; Aphonopelma phanum, Aphonopelma reversum = Aphonopelma steindachneri), 14 new species (Aphonopelma atomicum sp. n., Aphonopelma catalina sp. n., Aphonopelma chiricahua sp. n., Aphonopelma icenoglei sp. n., Aphonopelma johnnycashi sp. n., Aphonopelma madera sp. n., Aphonopelma mareki sp. n., Aphonopelma moellendorfi sp. n., Aphonopelma parvum sp. n., Aphonopelma peloncillo sp. n., Aphonopelma prenticei sp. n., Aphonopelma saguaro sp. n., Aphonopelma superstitionense sp. n., and Aphonopelma xwalxwal sp. n.), and seven nomina dubia (Aphonopelma baergi, Aphonopelma cratium, Aphonopelma hollyi, Aphonopelma mordax, Aphonopelma radinum, Aphonopelma rusticum, Aphonopelma texense). Our proposed species tree based on Anchored Enrichment data delimits five major lineages: a monotypic group confined to California, a western group, an eastern group, a group primarily distributed in high-elevation areas, and a group that comprises several miniaturized species. Multiple species are distributed throughout two biodiversity hotspots in the United States (i.e., California Floristic Province and Madrean Pine-Oak Woodlands). Keys are provided for identification of both males and females. By conducting the most comprehensive sampling of a single theraphosid genus to date, this research significantly broadens the scope of prior molecular and morphological investigations, finally bringing a modern understanding of species delimitation in this dynamic and charismatic group of spiders.     

Production and energy flow in the benthic community of a Texas pond

Energy flow (A = R + P; assimilation = respiration + production) and life-history/density-biomass cycles were followed for 1 year in a mayfly (Brachycercus sp.) population and two chironomid (Procladius sp. and Tendipes decorus) populations in a 0.94 ha pond located in north-central Texas. Temperature (5, 10, 15, 20, 25 and 30°C) effects on R and patterns of metabolic compensation/acclimatization were determined for the mayfly and chironomids. Chironomid and mayfly populations dominated the nine benthic macroinvertebrates identified in the pond, with greatest abundances in winter and winter-spring respectively. Annual energy flow was 51 kcal m^–2 (R = 40 kcal, P = 11 kcal or 1.9 g) in Brachycercus sp., 23 kcal m^–2 (R = 5 kcal, P = 18 kcal or 2.4 g) in Procladius sp. and 74 kcal m^–2 (R = 17 kcal, P = 57 kcal or 6.0 g) in T. decorus. Each species metabolically compensated partially to temperatures en countered during their life histories.     

Survival,fidelity, and recovery rates of white-winged doves in Texas

Management of migratory birds at the national level has historically relied on regulatory boundaries for definition of harvest restrictions and estimation of demographic parameters. Most species of migratory game birds are not expanding their ranges, so migratory corridors are approximately fixed. White-winged doves (Zenaida asiatica), however, have undergone significant variation in population structure with marked range expansion occurring in Texas, and range contraction in Arizona, during the last 30 years. Because >85% of white-winged dove harvest in the United States (approx. 1.3 million annually) now occurs in Texas, information on vital rates of expanding white-winged dove populations is necessary for informed management. We used band recovery and mark–recapture data to investigate variation in survival and harvest across 3 geographic strata for white-winged doves banded in the pre-hunting season in Texas during 2007–2010. We banded 60,742 white-winged doves, recovered 2,458 bands via harvest reporting, and recaptured 455 known-age birds between 2007 and 2010. The best supporting model found some evidence for geographic differences in survival rates among strata (A–C) in both hatch-year (juvenile; A = 0.205 [SE = 0.0476], B = 0.213 [SE = 0.0278], C = 0.364 [SE = 0.0254]) and after-hatch year (adult; A = 0.483 [SE = 0.0775], B = 0.465 [SE = 0.0366], C = 0.538 [SE = 0.251]) birds. White-winged doves had a low probability of moving among strata (0.009) or being recaptured (0.002) across all strata. Harvest recovery rates were concordant with estimates for other dove species, but were variable across geographic strata. Based on our results, harvest management strategies for white-winged doves in Texas and elsewhere should consider differences in population vital rates among geographic strata. © 2012 The Wildlife Society.