Reporting guidelines for terrestrial respirometry: Building openness, transparency of metabolic rate and evaporative water loss data.

Respirometry is an important tool for understanding whole-animal energy and water balance in relation to the environment. Consequently, the growing number of studies using respirometry over the last decade warrants reliable reporting and data sharing for effective dissemination and research synthesis. We provide a checklist guideline on five key sections to facilitate the transparency, reproducibility, and replicability of respirometry studies: 1) materials, set up, plumbing, 2) subject conditions/maintenance, 3) measurement conditions, 4) data processing, and 5) data reporting and statistics, each with explanations and example studies.

A haplotype-resolved reference genome of a long-distance migratory bat, Pipistrellus nathusii (Keyserling & Blasius, 1839).

We present a complete, chromosome-scale reference genome for the long-distance migratory bat Pipistrellus nathusii. The genome encompasses both haplotypic sets of autosomes and the separation of both sex chromosomes by utilizing highly accurate long-reads and preserving long-range phasing information through the use of three-dimensional chromatin conformation capture sequencing (Hi-C). This genome, accompanied by a comprehensive protein-coding sequence annotation, provides a valuable genomic resource for future investigations into the genomic bases of long-distance migratory flight in bats as well as uncovering the genetic architecture, population structure and evolutionary history of Pipistrellus nathusii.

Effects of tag mass on the physiology and behaviour of common noctule bats.

Background: External tags, such as transmitters and loggers, are often used to study bat movements. However, physiological and behavioural effects on bats carrying tags have rarely been investigated, and recommendations on the maximum acceptable tag mass are rather based on rules of thumb than on rigorous scientific assessment.

Methods: We conducted a comprehensive three-step assessment of the potential physiological and behavioural effects of tagging bats, using common noctules Nyctalus noctula as a model.

Conversion efficiency of flight power is low, but increases with flight speed in the migratory bat .

The efficiency with which flying animals convert metabolic power to mechanical power dictates an individual's flight behaviour and energy requirements. Despite the significance of this parameter, we lack empirical data on conversion efficiency for most species as measurements are notoriously difficult to obtain. Furthermore, conversion efficiency is often assumed to be constant across flight speeds, even though the components driving flight power are speed-dependent.

Flexible Employment of Torpor in Squirrel Gliders (): An Adaptation to Unpredictable Climate?

AbstractTorpor is a highly effective response to counter various ecological and physiological bottlenecks in endotherms. In this study, we examined interrelations between thermoregulatory responses and key environmental variables in free-living squirrel gliders () in a habitat with drastic climatic and ecological changes across seasons. To this end, we measured body temperature () and heart rate () simultaneously throughout the year using implanted data loggers.

Pronounced differences in heart rate and metabolism distinguish daily torpor and short-term hibernation in two bat species.

Torpor, and its differential expression, is essential to the survival of many mammals and birds. Physiological characteristics of torpor appear to vary between those species that express strict daily heterothermy and those capable of multiday hibernation, but comparisons are complicated by the temperature-dependence of variables. Previous reviews have compared these different torpor strategies by measuring the depth and duration of torpor in multiple species.

Accelerometer informed time-energy budgets reveal the importance of temperature to the activity of a wild, arid zone canid.

Background: Globally, arid regions are expanding and becoming hotter and drier with climate change. For medium and large bodied endotherms in the arid zone, the necessity to dissipate heat drives a range of adaptations, from behaviour to anatomy and physiology. Understanding how apex predators negotiate these landscapes and how they balance their energy is important as it may have broad impacts on ecosystem function.

Echolocation at high intensity imposes metabolic costs on flying bats.

Vocalizations are of pivotal importance for many animals, yet sound propagation in air is severely limited. To expand their vocalization range, animals can produce high-intensity sounds, which can come at high energetic costs. High-intensity echolocation is thought to have evolved in bats because the costs of calling are reported to be negligible during flight.

Responding to the weather: energy budgeting by a small mammal in the wild.

Energy conservation is paramount for small mammals because of their small size, large surface area to volume ratio, and the resultant high heat loss to the environment. To survive on limited food resources and to fuel their expensive metabolism during activity, many small mammals employ daily torpor to reduce energy expenditure during the rest phase. We hypothesized that a small terrestrial semelparous marsupial, the brown antechinus , would maximize activity when foraging conditions were favorable to gain fat reserves before their intense breeding period, but would increase torpor use when conditions were poor to conserve these fat reserves.

Fatty acid profiles of the European migratory common noctule bat (Nyctalus noctula).

In animals, fatty acids (FA) are essential as structural components in membranes and for energy storage in adipocytes. Here, we studied the relative proportions of FA in a mammal with extreme changes in metabolic rates. Common noctule bats (Nyctalus noctula) switch from energetically demanding long-distance migration at high metabolic rates to regular torpor with extremely low metabolic rates.

Valuable carcasses: postmortem preservation of fatty acid composition in heart tissue.

In order to effectively conserve species, we must understand the structure and function of integral mechanisms at all levels of organismal organisation, from intracellular biochemistry to whole animal ecophysiology. The accuracy of biochemical analyses depend on the quality and integrity of the samples analysed. It is believed that tissue samples collected immediately postmortem provide the most reliable depiction of the living animal.

The electrocardiogram of vertebrates: Evolutionary changes from ectothermy to endothermy.

The electrocardiogram (ECG) reveals that heart chamber activation and repolarization are much faster in mammals and birds compared to ectothermic vertebrates of similar size. Temperature, however, affects electrophysiology of the heart and most data from ectotherms are determined at body temperatures lower than those of mammals and birds. The present manuscript is a review of the effects of temperature on intervals in the ECG of ectothermic and endothermic vertebrates rather than a hypothesis-testing original research article.

No effect of season on the electrocardiogram of long-eared bats (Nyctophilus gouldi) during torpor.

Heterothermic animals regularly undergo profound alterations of cardiac function associated with torpor. These animals have specialised tissues capable of withstanding fluctuations in body temperature > 30 °C without adverse effects. In particular, the hearts of heterotherms are able to resist fibrillation and discontinuity of the cardiac conduction system common in homeotherms during hypothermia.

Can bats sense smoke during deep torpor?

While torpor is a beneficial energy-saving strategy, it may incur costs if an animal is unable to respond appropriately to external stimuli, which is particularly true when it is necessary to escape from threats such as fire. We aimed to determine whether torpid bats, which are potentially threatened because they must fly to escape, can sense smoke and whether respiration rate (RR), heart rate (HR) and reaction time of torpid bats prior to and following smoke introduction is temperature-dependent. To test this we quantified RR and HR of captive Australian tree-roosting bats, Nyctophilus gouldi (n=5, ~10g), in steady-state torpor in response to short-term exposure to smoke from Eucalyptus spp.

Cold-hearted bats: uncoupling of heart rate and metabolism during torpor at sub-zero temperatures.

Many hibernating animals thermoregulate during torpor and defend their body temperature () near 0°C by an increase in metabolic rate. Above a critical temperature (), animals usually thermoconform. We investigated the physiological responses above and below for a small tree-dwelling bat (, ∼14 g) that is often exposed to sub-zero temperatures during winter.

Post-fire recovery of torpor and activity patterns of a small mammal.

To cope with the post-fire challenges of decreased availability of food and shelter, brown antechinus (), a small marsupial mammal, increase the use of energy-conserving torpor and reduce activity. However, it is not known how long it takes for animals to resume pre-fire torpor and activity patterns during the recovery of burnt habitat. Therefore, we tested the hypothesis that antechinus will adjust torpor use and activity after a fire depending on vegetation recovery.

Black or white? Physiological implications of roost colour and choice in a microbat.

Although roost choice in bats has been studied previously, little is known about how opposing roost colours affect the expression of torpor quantitatively. We quantified roost selection and thermoregulation in a captive Australian insectivorous bat, Nyctophilus gouldi (n=12) in winter when roosting in black and white coloured boxes using temperature-telemetry. We quantified how roost choice influences torpor expression when food was provided ad libitum or restricted in bats housed together in an outdoor aviary exposed to natural fluctuations of ambient temperature.

Measuring subcutaneous temperature and differential rates of rewarming from hibernation and daily torpor in two species of bats.

Prolonged and remote measurement of body temperature (Tb) in undisturbed small hibernators was not possible in the past because of technological limitations. Although passive integrated transponders (PITs) have been used previously to measure subcutaneous temperature (Tsub) during daily torpor in a small marsupial, no study has attempted to use these devices at Tbs below 10°C. Therefore, we investigated whether subcutaneous interscapular PITs can be used as a viable tool for measuring Tb in a small hibernating bat (Nyctophilus gouldi; Ng) and compared it with measurements of Tb during daily torpor in a heterothermic bat (Syconycteris australis; Sa).

Passive rewarming from torpor in hibernating bats: minimizing metabolic costs and cardiac demands.

Endothermic arousal from torpor is an energetically costly process and imposes enormous demands on the cardiovascular system, particularly during early stage arousal from low body temperature (Tb). To minimize these costs many bats and other heterothermic endotherms rewarm passively from torpor using solar radiation or fluctuating ambient temperature (Ta). Because the heart plays a critical role in the arousal process in terms of blood distribution and as a source of heat production, it is desirable to understand how the function of this organ responds to passive rewarming and how this relates to changes in metabolism and Tb.

Torpor and hypothermia: reversed hysteresis of metabolic rate and body temperature.

Regulated torpor and unregulated hypothermia are both characterized by substantially reduced body temperature (Tb) and metabolic rate (MR), but they differ physiologically. Although the remarkable, medically interesting adaptations accompanying torpor (e.g.

Heart rate as a predictor of metabolic rate in heterothermic bats.

While heart rate (fH) has been used as an indicator of energy expenditure, quantitative data showing the relationship between these variables are only available for normothermic animals. To determine whether fH also predicts oxygen consumption ( ) during torpor, we simultaneously measured , fH and subcutaneous body temperature (Tsub) of a hibernator, Gould's long-eared bats (Nyctophilus gouldi, 9 g, N=18), at ambient temperatures (Ta) between 0 and 25°C. At rest, fH of normothermic resting bats was negatively correlated with Ta, with maximum fH of 803 beats min(-1) (Ta=5°C).

Bringing the troops back home: Modeling the postdeployment reintegration experience.

Using a sample of Canadian Forces personnel (N = 490) returning from deployment in Afghanistan, we tested a model of reintegration experiences, with a focus on affective organizational commitment, support factors, posttraumatic stress symptoms, changes in alcohol use, and turnover intentions. The model provided an excellent fit to the data, although homecoming experiences were not associated with commitment as predicted. No differences emerged between novice (single tour) and experienced (multiple tours) personnel, although the number of tours was associated with increased affective commitment as expected.

Examining unusual digit span performance in a population of postsecondary students assessed for academic difficulties.

Methods of identifying poor test-related motivation using the Wechsler Adult Intelligence Scale Digit Span subtest are based on identification of performance patterns that are implausible if the test taker is investing full effort. No studies to date, however, have examined the specificity of such measures, particularly when evaluating persons with either known or suspected learning or attention disorders. This study investigated performance of academically challenged students on three measures embedded in the Wechsler Adult Intelligence Scale-III, namely, low Digit Span, high Vocabulary-Digit span (Voc-DS), and low Reliable Digit Span scores.