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Bats (order Chiroptera) are emerging as instructive animal models for aging studies. Unlike some common laboratory species, they meet a central criterion for aging studies: they live for a long time in the wild or in captivity, for 20, 30, and even >40 years. Healthy aging (i.e., healthspan) in bats has drawn attention to their potential to improve the lives of aging humans due to bat imperviousness to viral infections, apparent low rate of tumorigenesis, and unique ability to repair DNA. At the same time, bat longevity also permits the accumulation of age‐associated systemic pathologies that can be examined in detail and manipulated, especially in captive animals. Research has uncovered additional and critical advantages of bats. In multiple ways, bats are better analogs to humans than are rodents. In this review, we highlight eight diverse areas of bat research with relevance to aging: genome sequencing, telomeres, and DNA repair; immunity and inflammation; hearing; menstruation and menopause; skeletal system and fragility; neurobiology and neurodegeneration; stem cells; and senescence and mortality. These examples demonstrate the broad relevance of the bat as an animal model and point to directions that are particularly important for human aging studies. [ABSTRACT FROM AUTHOR]

Exceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity. We demonstrate that DNAm accurately predicts chronological age. Across species, longevity is negatively associated with the rate of DNAm change at age-associated sites. Furthermore, analysis of several bat genomes reveals that hypermethylated age- and longevity-associated sites are disproportionately located in promoter regions of key transcription factors (TF) and enriched for histone and chromatin features associated with transcriptional regulation. Predicted TF binding site motifs and enrichment analyses indicate that age-related methylation change is influenced by developmental processes, while longevity-related DNAm change is associated with innate immunity or tumorigenesis genes, suggesting that bat longevity results from augmented immune response and cancer suppression. DNA methylation profiles from 26 bat species accurately predicts chronological age, while longevity-related methylation patterns across the genome suggest that bat longevity results from augmented immune response and cancer suppression. [ABSTRACT FROM AUTHOR]

Comparative analyses of bats indicate that hibernation is associated with increased longevity among species. However, it is not yet known if hibernation affects biological ageing of individuals. Here, we use DNA methylation (DNAm) as an epigenetic biomarker of ageing to determine the effect of hibernation on the big brown bat, Eptesicus fuscus. First, we compare epigenetic age, as predicted by a multi-species epigenetic clock, between hibernating and non-hibernating animals and find that hibernation is associated with epigenetic age. Second, we identify genomic sites that exhibit hibernation-associated change in DNAm, independent of age, by comparing samples taken from the same individual in hibernating and active seasons. This paired comparison identified over 3000 differentially methylated positions (DMPs) in the genome. Genome-wide association comparisons to tissue-specific functional elements reveals that DMPs with elevated DNAm during winter occur at sites enriched for quiescent chromatin states, whereas DMPs with reduced DNAm during winter occur at sites enriched for transcription enhancers. Furthermore, genes nearest DMPs are involved in regulation of metabolic processes and innate immunity. Finally, significant overlap exists between genes nearest hibernation DMPs and genes nearest previously identified longevity DMPs. Taken together, these results are consistent with hibernation influencing ageing and longevity in bats. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2006.09.003 Byline: Kirsten M. Bohn, Gerald S. Wilkinson, Cynthia F. Moss Abstract: In colonial species, recognition of offspring should be under strong selection. For accurate identification to occur, offspring must produce individually distinctive signals and parents must be able to discriminate between signals. Female greater spear-nosed bats roost in stable social groups and use infant vocalizations, termed isolation calls, to locate and identify their young. In this study, we investigated both the production and perception of isolation calls in P. hastatus. First, we measured acoustic features of calls and found that, after controlling for ontogenetic effects, sufficient variation exists between pups for isolation calls to function as individual signatures. Moreover, calls of pups from the same social group were more similar in spectral and spectrotemporal features than were calls of pups from different social groups, indicating that these features are probably heritable. We used psychoacoustic experiments in the laboratory to determine whether adult females could discriminate between calls from pups in the same or different social group. Females discriminated between pups when faced with a template-matching task and their performance was correlated with the salience of spectral and spectrotemporal features. We found no difference in performance when females had to discriminate between pups from the same and different social groups. These results indicate that females should be able to accurately identify their young using isolation calls. Author Affiliation: (a) Department of Biology, University of Maryland, U.S.A. (a ) Department of Psychology, University of Maryland, U.S.A. Article History: Received 22 March 2006; Revised 18 May 2006; Accepted 5 September 2006 Article Note: (miscellaneous) MS. number: A10399

The social calls emitted by the greater spear-nosed bats, Phyllostomus hastatus are contact calls that coordinate foraging activities in this species. This is the conclusion drawn from seasonal observations and playback investigations undertaken in colonies in Trinidad, West Indies. The evidences that proved these screeches to be social calls in the greater spear-nosed bats are presented.

Exceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity. We demonstrate that DNAm accurately predicts chronological age. Across species, longevity is negatively associated with the rate of DNAm change at age-associated sites. Furthermore, analysis of several bat genomes reveals that hypermethylated age- and longevity-associated sites are disproportionately located in promoter regions of key transcription factors (TF) and enriched for histone and chromatin features associated with transcriptional regulation. Predicted TF binding site motifs and enrichment analyses indicate that age-related methylation change is influenced by developmental processes, while longevity-related DNAm change is associated with innate immunity or tumorigenesis genes, suggesting that bat longevity results from augmented immune response and cancer suppression. DNA methylation profiles from 26 bat species accurately predicts chronological age, while longevity-related methylation patterns across the genome suggest that bat longevity results from augmented immune response and cancer suppression. [ABSTRACT FROM AUTHOR]

Group-living animals can potentially enhance their foraging performance and efficiency by obtaining information from others. Using PIT-tag data to study foraging behaviour in individual bats, we tested short-tailed fruit bats, Carollia perspicillata (Linnaeus), for evidence of local enhancement or social facilitation. To discriminate between these phenomena, we manipulated the presence of conspecifics while individuals searched for food. We quantified the time to find food and the order and sex of bats accessing the food, and any consistent associations between bats. Presence of conspecifics decreased the time needed to find food. We found no evidence that pairs of individuals consistently fed together; however, bats of the same sex tended to feed closer in time with one another. The same individuals consistently accessed the food first, and males found food more quickly than females. Our results provide evidence of social facilitation, with bats finding food more quickly in a group than alone. [ABSTRACT FROM AUTHOR]

The comparative approach can provide insight into the evolution of human speech, language and social communication by studying relevant traits in animal systems. Bats are emerging as a model system with great potential to shed light on these processes given their learned vocalizations, close social interactions, and mammalian brains and physiology. A recent framework outlined the multiple levels of investigation needed to understand vocal learning across a broad range of non-human species, including cetaceans, pinnipeds, elephants, birds and bats. Here, we apply this framework to the current state-of-the-art in bat research. This encompasses our understanding of the abilities bats have displayed for vocal learning, what is known about the timing and social structure needed for such learning, and current knowledge about the prevalence of the trait across the order. It also addresses the biology (vocal tract morphology, neurobiology and genetics) and evolution of this trait. We conclude by highlighting some key questions that should be answered to advance our understanding of the biological encoding and evolution of speech and spoken communication. This article is part of the theme issue 'What can animal communication teach us about human language?' [ABSTRACT FROM AUTHOR]

For echolocating bats, hearing is essential for survival. Specializations for detecting and processing high frequency sounds are apparent throughout their auditory systems. Recent studies on echolocating mammals have reported evidence of parallel evolution in some hearing-related genes in which distantly related groups of echolocating animals (bats and toothed whales), cluster together in gene trees due to apparent amino acid convergence. However, molecular adaptations can occur not only in coding sequences, but also in the regulation of gene expression. The aim of this study was to examine the expression of hearing-related genes in the inner ear of developing big brown bats, Eptesicus fuscus, during the period in which echolocation vocalizations increase dramatically in frequency. We found that seven genes were significantly upregulated in juveniles relative to adults, and that the expression of four genes through development correlated with estimated age. Compared to available data for mice, it appears that expression of some hearing genes is extended in juvenile bats. These results are consistent with a prolonged growth period required to develop larger cochlea relative to body size, a later maturation of high frequency hearing, and a greater dependence on high frequency hearing in echolocating bats. [ABSTRACT FROM AUTHOR]

These authors contributed equally: Gerald S. Wilkinson, Steve Horvath. Correction to: I Nature Communications i https://doi.org/10.1038/s41467-021-21900-2, published online 12 March 2021 The previous version of the Supplementary Information associated with this Article omitted Supplementary Figures 1-6. [Extracted from the article]

These authors contributed equally: Gerald S. Wilkinson, Steve Horvath. The original version of this Article contained an error in the email address of the corresponding author Steve Horvath, which was missing the terminal edu and should be shorvath@mednet.ucla.edu These have been corrected in both the PDF and HTML versions of the Article. [Extracted from the article]

Abstract: Bats and birds live substantially longer on average than non-flying mammals of similar body size. The combination of small body size, high metabolic rates, and long lifespan in bats and birds would not seem to support oxidative theories of ageing that view senescence as the gradual accumulation of damage from metabolic byproducts. However, large-scale comparative analyses and laboratory studies on a few emerging model species have identified multiple mechanisms for resisting oxidative damage to mitochondrial DNA and cellular structures in both bats and birds. Here we review these recent findings, and suggest areas in which additional progress on ageing mechanisms can be made using bats and birds as novel systems. New techniques for determining the age of free-living, wild individuals, and robustly supported molecular phylogenies, are under development and will improve the efforts of comparative biologists to identify ecological and evolutionary factors promoting long lifespan. In the laboratory, greater development of emerging laboratory models and comparative functional genomic approaches will be needed to identify the molecular pathways of longevity extension in birds and bats. [Copyright &y& Elsevier]

The use of vocalizations by males to attract mates and defend territories is widespread in birds but uncommon in mammals. In the greater white-lined bat, males defend small territories in tree buttresses and produce complex audible vocalizations. During the day, females roost within these territories, and males with females in their territories have higher reproductive success than males without females. To determine call function, we recorded male vocalizations on the island of Trinidad and made behavioural observations of the focal male and nearby bats at the time the calls were given. Noisy broadband calls were directed mainly at other males whereas tonal calls were used primarily in interactions with females. Two other types of calls were given independently of any observable context and may be involved in territorial defence or conspecific notification. Poisson regression showed that males with song repertoires that contained more unique types of composite syllables had more females in their territories. In addition, several acoustic features of one common call type significantly correlated with the number of females on a territory. Male vocalizations may, therefore, transfer information to colony members about male quality or fighting ability. [Copyright &y& Elsevier]

Focuses on the evolution of repeated sequence arrays in the D-loop region of bat mitochondrial deoxyribonucleic acid (DNA). Information on animal mitochondria; Details on the function of the D-loop.

Gerald Wilkinson introduces the blood-drinking vampire bats. [ABSTRACT FROM AUTHOR]

Summary Observations of animals feeding in aggregations are often interpreted as events of social foraging, but it can be difficult to determine whether the animals arrived at the foraging sites after collective search [ 1–4 ] or whether they found the sites by following a leader [ 5, 6 ] or even independently, aggregating as an artifact of food availability [ 7, 8 ]. Distinguishing between these explanations is important, because functionally, they might have very different consequences. In the first case, the animals could benefit from the presence of conspecifics, whereas in the second and third, they often suffer from increased competition [ 3, 9–13 ]. Using novel miniature sensors, we recorded GPS tracks and audio of five species of bats, monitoring their movement and interactions with conspecifics, which could be inferred from the audio recordings. We examined the hypothesis that food distribution plays a key role in determining social foraging patterns [ 14–16 ]. Specifically, this hypothesis predicts that searching for an ephemeral resource (whose distribution in time or space is hard to predict) is more likely to favor social foraging [ 10, 13–15 ] than searching for a predictable resource. The movement and social interactions differed between bats foraging on ephemeral versus predictable resources. Ephemeral species changed foraging sites and showed large temporal variation nightly. They aggregated with conspecifics as was supported by playback experiments and computer simulations. In contrast, predictable species were never observed near conspecifics and showed high spatial fidelity to the same foraging sites over multiple nights. Our results suggest that resource (un)predictability influences the costs and benefits of social foraging. Highlights • Miniature GPS-microphone tags allow monitoring wild bats' movement and interactions • Bats foraging on ephemeral resources move in groups in variable movement patterns • Bats foraging on predictable resources move alone and in fixed movement patterns • Results support the hypothesis that resource predictability shapes group foraging Using miniature tags, Egert-Berg et al. record bats' movement and social interactions. Whereas species foraging on ephemeral resources search in groups, switching foraging sites, species foraging on predictable resources search alone, returning to the same sites. The results suggest a connection between resource predictability and group foraging. [ABSTRACT FROM AUTHOR]