Bat tracking across Europe.

New technology answers questions about the seasonal migration of bats.

Echoes through time: amazing inferences from a fossil bat.

Sister to the Chiroptera crown-clade, the 50 million year old Vielasia sigei is suggested to have used laryngeal echolocation based on morphometric analyses. We discuss how Vielasia's discovery influences our understanding of the evolution of echolocation in bats and the insights fossils provide to the lives of extinct species.

Heterothermic Migration Strategies in Flying Vertebrates.

Migration is a widespread and highly variable trait among animals. Population-level patterns arise from individual-level decisions, including physiological and energetic constraints. Many aspects of migration are influenced by behaviors and strategies employed during periods of stopover, where migrants may encounter variable or unpredictable conditions.

Lean Mass Dynamics in Hibernating Bats and Implications for Energy and Water Budgets.

AbstractHibernation requires balancing energy and water demands over several months. Many studies have noted the importance of fat for hibernation energy budgets, but protein catabolism in hibernation has received less attention, and whole-animal changes in lean mass have not previously been considered. We used quantitative magnetic resonance body composition analysis to measure deposition of fat and lean mass of cave myotis () during the prehibernation period and decreases in fat and lean mass of Townsend's big-eared bats () during hibernation.

Experimental inoculation trial to determine the effects of temperature and humidity on White-nose Syndrome in hibernating bats.

Disease results from interactions among the host, pathogen, and environment. Inoculation trials can quantify interactions among these players and explain aspects of disease ecology to inform management in variable and dynamic natural environments. White-nose Syndrome, a disease caused by the fungal pathogen, Pseudogymnoascus destructans (Pd), has caused severe population declines of several bat species in North America.

Interspecific variation in evaporative water loss and temperature response, but not metabolic rate, among hibernating bats.

Hibernation is widespread among mammals in a variety of environmental contexts. However, few experimental studies consider interspecific comparisons, which may provide insight into general patterns of hibernation strategies. We studied 13 species of free-living bats, including populations spread over thousands of kilometers and diverse habitats.

Similar hibernation physiology in bats across broad geographic ranges.

Species with broad geographic ranges may experience varied environmental conditions throughout their range leading to local adaptation. Variation among populations reflects potential adaptability or plasticity, with implications for populations impacted by disease, climate change, and other anthropogenic influences. However, behavior may counteract divergent selection among populations.

Temperature alone is insufficient to understand hibernation energetics.

Energy conservation has long been a focal point in hibernation research. A long-standing assumption is that ambient temperature (Ta) largely defines the rate of energy expenditure because of well-known relationships between Ta, metabolic rate and frequency of arousal from torpor. Body condition and humidity also affect energy expenditure but are usually considered secondary factors.

Exploiting common senses: sensory ecology meets wildlife conservation and management.

Multidisciplinary approaches to conservation and wildlife management are often effective in addressing complex, multi-factor problems. Emerging fields such as conservation physiology and conservation behaviour can provide innovative solutions and management strategies for target species and systems. Sensory ecology combines the study of 'how animals acquire' and process sensory stimuli from their environments, and the ecological and evolutionary significance of 'how animals respond' to this information.

Disease recovery in bats affected by white-nose syndrome.

Processes associated with recovery of survivors are understudied components of wildlife infectious diseases. White-nose syndrome (WNS) in bats provides an opportunity to study recovery of disease survivors, understand implications of recovery for individual energetics, and assess the role of survivors in pathogen transmission. We documented temporal patterns of recovery from WNS in little brown bats () following hibernation to test the hypotheses that: (1) recovery of wing structure from WNS matches a rapid time scale (i.

Incorporating evaporative water loss into bioenergetic models of hibernation to test for relative influence of host and pathogen traits on white-nose syndrome.

Hibernation consists of extended durations of torpor interrupted by periodic arousals. The 'dehydration hypothesis' proposes that hibernating mammals arouse to replenish water lost through evaporation during torpor. Arousals are energetically expensive, and increased arousal frequency can alter survival throughout hibernation.

Migration and reproduction are associated with similar degrees of phenotypic flexibility in an insectivorous bat.

As organisms face variation in energetic challenges and physiological demands, they often respond with reversible changes in behavior, physiology, and morphology, described as phenotypic flexibility. From the magnitude of phenotypic change, we can infer the energetic challenges of different life stages. We studied phenotypic flexibility in a population of reproductive and pre-migratory female insectivorous bats (Tadarida brasiliensis).

Seasonal Dynamics of Lipid Metabolism and Energy Storage in the Brazilian Free-Tailed Bat.

As small, flying, mammalian endotherms, insectivorous bats are adapted to operate at high levels of energy expenditure. In response to seasonally variable challenges, we predicted that bats should balance energy budgets by flexibly adjusting aspects of their physiology or behavior in ways that elevate metabolic capacity. We examined variation in energy storage and pathways for oxidative metabolism in Brazilian free-tailed bats () related to estimated costs associated with reproduction and migration.

Testing the "Fasting While Foraging" Hypothesis: Effects of Recent Feeding on Plasma Metabolite Concentrations in Little Brown Bats ().

Plasma metabolite concentrations can be used to understand nutritional status and foraging behavior across ecological contexts including prehibernation fattening, migration refueling, and variation in foraging habitat quality. Generally, high plasma concentrations of the ketone β-hydroxybutyrate, a product of fat catabolism, indicate fasting, while triglycerides indicate recent feeding and fat accumulation. In recent studies of insectivorous bats, triglyceride concentration increased after feeding as expected, but β-hydroxybutyrate also unexpectedly increased rather than decreased.

Bats are not squirrels: Revisiting the cost of cooling in hibernating mammals.

Many species use stored energy to hibernate through periods of resource limitation. Hibernation, a physiological state characterized by depressed metabolism and body temperature, is critical to winter survival and reproduction, and therefore has been extensively quantified and modeled. Hibernation consists of alternating phases of extended periods of torpor (low body temperature, low metabolic rate), and energetically costly periodic arousals to normal body temperature.

An experimental test of energy and electrolyte supplementation as a mitigation strategy for white-nose syndrome.

Fungi are increasingly recognised as harmful pathogens of wildlife. White-nose syndrome (WNS) is a fungal disease that has killed millions of hibernating bats in North America. High mortality has driven research to identify management strategies for the disease.

Environmentally persistent pathogens present unique challenges for studies of host-pathogen interactions: Reply to Field (2018).

: https://doi.org/10.1002/ece3.

The other white-nose syndrome transcriptome: Tolerant and susceptible hosts respond differently to the pathogen .

Mitigation of emerging infectious diseases that threaten global biodiversity requires an understanding of critical host and pathogen responses to infection. For multihost pathogens where pathogen virulence or host susceptibility is variable, host-pathogen interactions in tolerant species may identify potential avenues for adaptive evolution in recently exposed, susceptible hosts. For example, the fungus causes white-nose syndrome (WNS) in hibernating bats and is responsible for catastrophic declines in some species in North America, where it was recently introduced.

White-nose syndrome increases torpid metabolic rate and evaporative water loss in hibernating bats.

Fungal diseases of wildlife typically manifest as superficial skin infections but can have devastating consequences for host physiology and survival. White-nose syndrome (WNS) is a fungal skin disease that has killed millions of hibernating bats in North America since 2007. Infection with the fungus causes bats to rewarm too often during hibernation, but the cause of increased arousal rates remains unknown.

Tectal corticotropin-releasing factor (CRF) neurons respond to fasting and a reactive stressor in the African Clawed Frog, Xenopus laevis.

It is well established that hypothalamic neurons producing the peptide corticotropin-releasing factor (CRF) play a key role in stress adaptation, including reduction of food intake when a threat or stressor is present. We have previously reported on the presence of an intrinsic CRF signaling system within the optic tectum (OT), a brain area that plays a key role in visually guided prey capture/predator avoidance decisions. To better understand the potential role of tectal CRF neurons in regulating adaptive behavior and energy balance during stress we examined evidence for modulation of tectal CRF neuronal activity after stressor exposure and food deprivation in the African clawed frog Xenopus laevis.

Body temperatures of hibernating little brown bats reveal pronounced behavioural activity during deep torpor and suggest a fever response during white-nose syndrome.

Hibernating animals use torpor [reduced body temperature (T ) and metabolic rate] to reduce energy expenditure during winter. Periodic arousals to normal T are energetically expensive, so hibernators trade off arousal benefits against energetic costs. This is especially important for bats with white-nose syndrome (WNS), a fungal disease causing increased arousal frequency.

Physiological and behavioral adaptations in bats living at high latitudes.

Widespread animals at the extremes of the species' distribution experience ecological constraints different than individuals in the core of the distribution. For example, small endotherms at very high latitudes face short summers with cool temperatures and a lack of true darkness. In particular, insectivorous bats at high latitudes may experience constraints because of their unique life history traits, and may have different energy requirements than bats at lower latitudes.

Metabolic rate, latitude and thermal stability of roosts, but not phylogeny, affect rewarming rates of bats.

Torpor is an adaptation that allows many endotherms to save energy by abandoning the energetic cost of maintaining elevated body temperatures. Although torpor reduces energy consumption, the metabolic heat production required to arouse from torpor is energetically expensive and can impact the overall cost of torpor. The rate at which rewarming occurs can impact the cost of arousal, therefore, factors influencing rewarming rates of heterothermic endotherms could have influenced the evolution of rewarming rates and overall energetic costs of arousal from torpor.

White-Nose Syndrome Disease Severity and a Comparison of Diagnostic Methods.

White-nose syndrome is caused by the fungus Pseudogymnoascus destructans and has killed millions of hibernating bats in North America but the pathophysiology of the disease remains poorly understood. Our objectives were to (1) assess non-destructive diagnostic methods for P. destructans infection compared to histopathology, the current gold-standard, and (2) to evaluate potential metrics of disease severity.