ABSTRACT
Cross-species transmission of viruses from wildlife animal reservoirs poses a marked threat to human and animal health 1 . Bats have been recognized as one of the most important reservoirs for emerging viruses and the transmission of a coronavirus that originated in bats to humans via intermediate hosts was responsible for the high-impact emerging zoonosis, severe acute respiratory syndrome (SARS) 2-10 . Here we provide virological, epidemiological, evolutionary and experimental evidence that a novel HKU2-related bat coronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), is the aetiological agent that was responsible for a large-scale outbreak of fatal disease in pigs in China that has caused the death of 24,693 piglets across four farms. Notably, the outbreak began in Guangdong province in the vicinity of the origin of the SARS pandemic. Furthermore, we identified SADS-related CoVs with 96-98% sequence identity in 9.8% (58 out of 591) of anal swabs collected from bats in Guangdong province during 2013-2016, predominantly in horseshoe bats (Rhinolophus spp.) that are known reservoirs of SARS-related CoVs. We found that there were striking similarities between the SADS and SARS outbreaks in geographical, temporal, ecological and aetiological settings. This study highlights the importance of identifying coronavirus diversity and distribution in bats to mitigate future outbreaks that could threaten livestock, public health and economic growth.
Subject(s)
Alphacoronavirus/isolation & purification , Alphacoronavirus/pathogenicity , Animal Diseases/epidemiology , Animal Diseases/virology , Chiroptera/virology , Coronavirus Infections/veterinary , Diarrhea/veterinary , Swine/virology , Alphacoronavirus/classification , Alphacoronavirus/genetics , Animal Diseases/transmission , Animals , Biodiversity , China/epidemiology , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Diarrhea/pathology , Diarrhea/virology , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Genome, Viral/genetics , Humans , Jejunum/pathology , Jejunum/virology , Phylogeny , Severe Acute Respiratory Syndrome/epidemiology , Severe Acute Respiratory Syndrome/veterinary , Severe Acute Respiratory Syndrome/virology , Spatio-Temporal Analysis , Zoonoses/epidemiology , Zoonoses/transmission , Zoonoses/virologyABSTRACT
The flight of bats is comparatively less documented and understood than birds and insects and may provide novel inspiration for the design of flapping flight robots. This study captured the natural flight of short-nosed fruit bats (Cynopterus sphinx) by an optical motion capture system, "OptiTrack", with pasted markers on the wings and body to reconstruct the flight parameters. Due to the self-occlusion at some moments, points on the membrane wings cannot be captured by any cameras. To draw a smooth trajectory, it is desired to reconstruct all missing data. Therefore, an algorithm is proposed by using numerical techniques, accompanied by modern mathematical and computational tools, to envisage the missing data from the captured flight. The least-square fitted polynomial engendered the parameter equations for x-, y-, and z-coordinates of marked points which were used to reconstruct the trajectory of the flight. The parameter equations of position coordinates were also used to compute the morphological and aerodynamic characteristics of the flight. The most outstanding contribution of the work is that not only the trajectory, velocity, and velocity field but also the morphing areas of the membrane wings were recreated using the reconstructed data. These data and reconstructed curves of trajectory and velocity field will be used for the further aerodynamic analysis and mechanism design of the flapping robot. This method can also be generalized to reconstruct the performance parameters of any other animals for bionic design.
Subject(s)
Chiroptera , Robotics , Animals , Biomechanical Phenomena , Flight, Animal , Models, Biological , Wings, Animal/anatomy & histologyABSTRACT
Bat is the only mammal in the nature that can fly. Compared with birds and insects, bats are quite special in that their wings are formed by an elastic membrane, which renders that the airfoil deforms greatly during downstroke and upstroke. Due to the compliant skin of a bat, the movements of its wings are three-dimensionally complex during diverse flight behaviors. To understand the maneuverability and flight performance, three-dimensional reconstruction of the flight kinematics is essential. This study focuses on the reconstruction of the wing kinematics of the bat and identifies the primary relationship of parameters of aerodynamics in straight flight. With markers pasted on the wings and body of a bat, the motions of these points are recorded by a computerized optical motion capture system. The kinematic analysis shows that the motion of wings is very intricate. The digits of the wing display the sign of coupled motion. A novel approach was developed to measure the angle of attack and flapping angle of the wing. The angle of attack of leading edge differs with the overall angle of attack of the wing. The kinematics of the bat's wing is helpful to interpret the secret of the bat's flight.
Subject(s)
Chiroptera , AnimalsABSTRACT
Bats have been reported to carry diverse adenoviruses. However, most bat adenoviruses have been identified on the basis of partial genome sequences, and knowledge on the evolution of bat adenoviruses remains limited. In this study, we isolated and characterized four novel adenoviruses from two distinct bat species, and their full-length genomes were sequenced. Sequence analysis revealed that these isolates represented three distinct species of the genus Mastadenovirus. However, all isolates had an exceptionally low G+C content and relatively short genomes compared with other known mastadenoviruses. We further analysed the relationships among the G+C content, 5'-C-phosphate-G-3' (CpG) representation and genome size in the family Adenoviridae. Our results revealed that the CpG representation in adenoviral genomes depends primarily on the level of methylation, and the genome size displayed significant positive correlations with both G+C content and CpG representation. Since ancestral adenoviruses are believed to have contained short genomes, those probably had a low G+C content, similar to the genomes of these bat strains. Our results suggest that bats are important natural reservoirs for adenoviruses and play important roles in the evolution of adenoviruses.
Subject(s)
Adenoviridae/genetics , Chiroptera/virology , Evolution, Molecular , Adenoviridae/classification , Adenoviridae/isolation & purification , Animals , Base Composition , Base Sequence , Genome Size , Genome, Viral , Molecular Sequence Data , PhylogenyABSTRACT
BACKGROUND: In recent years, novel hepadnaviruses, hepeviruses, hepatoviruses, and hepaciviruses have been discovered in various species of bat around the world, indicating that bats may act as natural reservoirs for these hepatitis viruses. In order to further assess the distribution of hepatitis viruses in bat populations in China, we tested the presence of these hepatitis viruses in our archived bat liver samples that originated from several bat species and various geographical regions in China. METHODS: A total of 78 bat liver samples (involving two families, five genera, and 17 species of bat) were examined using nested or heminested reverse transcription PCR (RT-PCR) with degenerate primers. Full-length genomic sequences of two virus strains were sequenced followed by phylogenetic analyses. RESULTS: Four samples were positive for hepadnavirus, only one was positive for hepevirus, and none of the samples were positive for hepatovirus or hepacivirus. The hepadnaviruses were discovered in the horseshoe bats, Rhinolophus sinicus and Rhinolophus affinis, and the hepevirus was found in the whiskered bat Myotis davidii. The full-length genomic sequences were determined for one of the two hepadnaviruses identified in R. sinicus (designated BtHBVRs3364) and the hepevirus (designated BtHEVMd2350). A sequence identity analysis indicated that BtHBVRs3364 had the highest degree of identity with a previously reported hepadnavirus from the roundleaf bat, Hipposideros pomona, from China, and BtHEVMd2350 had the highest degree of identity with a hepevirus found in the serotine bat, Eptesicus serotinus, from Germany, but it exhibited high levels of divergence at both the nucleotide and the amino acid levels. CONCLUSIONS: This is the first study to report that the Chinese horseshoe bat and the Chinese whiskered bat have been found to carry novel hepadnaviruses and a novel hepevirus, respectively. The discovery of BtHBVRs3364 further supports the significance of host switches evolution while opposing the co-evolutionary theory associated with hepadnaviruses. According to the latest criterion of the International Committee on Taxonomy of Viruses (ICTV), we hypothesize that BtHEVMd2350 represents an independent genotype within the species Orthohepevirus D of the family Hepeviridae.
Subject(s)
Chiroptera/virology , Hepadnaviridae/classification , Hepadnaviridae/isolation & purification , Hepevirus/classification , Hepevirus/isolation & purification , Liver/virology , Phylogeny , Animals , China , Cluster Analysis , Genome, Viral , Hepadnaviridae/genetics , Hepevirus/genetics , Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNAABSTRACT
Bats carry diverse RNA viruses, some of which are responsible for human diseases. Compared to bat-borne RNA viruses, relatively little information is known regarding bat-borne DNA viruses. In this study, we isolated and characterized three novel bat adenoviruses (BtAdV WIV9-11) from Rhinolophus sinicus. Their genomes, which are highly similar to each other but distinct from those of previously sequenced adenoviruses (AdVs), are 37 545, 37 566 and 38 073 bp in size, respectively. An unusually large E3 gene was identified in their genomes. Phylogenetic and taxonomic analyses suggested that these isolates represent a distinct species of the genus Mastadenovirus. Cell susceptibility assays revealed a broad cell tropism for these isolates, indicating that they have a potentially wide host range. Our results expand the understanding of genetic diversity of bat AdVs.
Subject(s)
Adenovirus E3 Proteins/genetics , Chiroptera/virology , Genome, Viral/genetics , Mastadenovirus/classification , Mastadenovirus/genetics , Animals , Base Sequence , Capsid Proteins/genetics , Chlorocebus aethiops , Cricetinae , DNA, Viral/genetics , Genetic Variation/genetics , Host Specificity , Humans , Macaca mulatta , Phylogeny , Sequence Analysis, DNA , Swine , Viral TropismABSTRACT
Bats have been identified as natural reservoirs of many viruses, including reoviruses. Recent studies have demonstrated the interspecies transmission of bat reoviruses to humans. In this study, we report the isolation and molecular characterization of six strains of mammalian orthoreovirus (MRV) from Hipposideros and Myotis spp. These isolates were grouped into MRV serotype 1, 2 or 3 based on the sequences of the S1 gene, which encodes the outer coat protein s1. Importantly, we found that three of six bat MRV strains shared high similarity with MRVs isolated from diseased minks, piglets or humans based on the S1 segment, suggesting that interspecies transmission has occurred between bats and humans or animals. Phylogenetic analyses based on the 10 segments showed that the genomic segments of these bat MRVs had different evolution lineages, suggesting that these bat MRVs may have arisen through reassortment of MRVs of different origins.
Subject(s)
Chiroptera/virology , Mink/virology , Orthoreovirus, Mammalian/classification , Orthoreovirus, Mammalian/isolation & purification , Reoviridae Infections/veterinary , Swine/virology , Animals , China/epidemiology , Disease Reservoirs/virology , Humans , Orthoreovirus, Mammalian/genetics , Phylogeny , Reoviridae Infections/epidemiology , Reoviridae Infections/transmission , Reoviridae Infections/virology , SerogroupABSTRACT
The ability to sense temperature changes is crucial for mammalian survival. Mammalian thermal sensing is primarily carried out by thermosensitive transient receptor potential channels (Thermo-TRPs). Some mammals hibernate to survive cold winter conditions, during which time their body temperature fluctuates dramatically. However, the underlying mechanisms by which these mammals regulate thermal responses remain unclear. Using quantitative real-time polymerase chain reaction (qRT-PCR) and the Western blotting, we found that Myotis ricketti bats had high levels of heat-activated TRPs (e.g., TRPV1 and TRPV4) during torpor in winter and cold-activated TRPs (e.g., TRPM8 and TRPC5) during active states in summer. We also found that laboratory mice had high mRNA levels of cold-activated TRPs (e.g., Trpm8 and Trpc5) under relatively hot conditions (i.e., 40 °C). These data suggest that small mammals up-regulate the expression of cold-activated TRPs even under warm or hot conditions. Binding site analysis showed that some homeobox (HOX) transcription factors (TFs) regulate the expression of hot- and cold-activated TRP genes and that some TFs of the Pit-Oct-Unc (POU) family regulate warm-sensitive and cold-activated TRP genes. The dual-luciferase reporter assay results demonstrated that TFs HOXA9, POU3F1, and POU5F1 regulate TRPC5 expression, suggesting that Thermo-TRP genes are regulated by multiple TFs of the HOX and POU families at different levels. This study provides insights into the adaptive mechanisms underlying thermal sensing used by bats to survive hibernation.
Subject(s)
Chiroptera , Hot Temperature , Seasons , TRPC Cation Channels , Animals , Chiroptera/genetics , Female , Hibernation/genetics , Male , Mice , TRPC Cation Channels/genetics , TRPV Cation Channels/geneticsABSTRACT
Bats are reservoirs of various viruses. The widely distributed cave nectar bat ( Eonycteris spelaea) is known to carry both filoviruses and coronaviruses. However, the potential transmission of theses bat viruses to humans is not fully understood. In this study, we tracked 16 E. spelaea bats in Mengla County, Yunnan Province, China, using miniaturized GPS devices to investigate their movements and potential contact with humans. Furthermore, to determine the prevalence of coronavirus and filovirus infections, we screened for the nucleic acids of the Menglà virus (MLAV) and two coronaviruses (GCCDC1-CoV and HKU9-CoV) in anal swab samples taken from bats and for antibodies against these viruses in human serum samples. None of the serum samples were found to contain antibodies against the bat viruses. The GPS tracking results showed that the bats did not fly during the daytime and rarely flew to residential areas. The foraging range of individual bats also varied, with a mean cumulative nightly flight distance of 25.50 km and flight speed of up to 57.4 km/h. Taken together, these results suggest that the risk of direct transmission of GCCDC1-CoV, HKU9-CoV, and MLAV from E. spelaea bats to humans is very low under natural conditions.
Subject(s)
Chiroptera , Coronavirus Infections , Viruses , Animals , China/epidemiology , Coronavirus Infections/veterinary , Humans , Phylogeny , Plant NectarABSTRACT
Exposure to intense noise can damage cochlear hair cells, leading to hearing loss in mammals. To avoid this constraint, most mammals have evolved in relatively quiet environments. Echolocating bats, however, are naturally exposed to continuous intense sounds from their own and neighboring sonar emissions for maintaining sonar directionality and range. Here, we propose the presence of intense noise resistance in cochlear hair cells of echolocating bats against noise-induced hearing loss (NIHL). To test this hypothesis, we performed noise exposure experiments for laboratory mice, one nonecholocating bat species, and five echolocating bat species. Contrary to nonecholocating fruit bats and mice, the hearing and the cochlear hair cells of echolocating bats remained unimpaired after continuous intense noise exposure. The comparative analyses of cochleae transcriptomic data showed that several genes protecting cochlear hair cells from intense sounds were overexpressed in echolocating bats. Particularly, the experimental examinations revealed that ISL1 overexpression significantly improved the survival of cochlear hair cells. Our findings support the existence of protective effects in cochlear hair cells of echolocating bats against intense noises, which provides new insight into understanding the relationship between cochlear hair cells and intense noises, and preventing or ameliorating NIHL in mammals.
Subject(s)
Chiroptera/physiology , Hair Cells, Auditory/physiology , Hearing , Noise , Animals , Auditory Threshold , Chiroptera/classification , Computational Biology/methods , Echolocation , Fluorescent Antibody Technique , Gene Expression Profiling , Gene Expression Regulation , Phylogeny , TranscriptomeABSTRACT
Bats have been identified as natural reservoirs of a variety of coronaviruses. They harbor at least 19 of the 33 defined species of alpha- and betacoronaviruses. Previously, the bat coronavirus HKU10 was found in two bat species of different suborders, Rousettus leschenaultia and Hipposideros pomona, in south China. However, its geographic distribution and evolution history are not fully investigated. Here, we screened this viral species by a nested reverse transcriptase PCR in our archived samples collected over 10 years from 25 provinces of China and one province of Laos. From 8004 bat fecal samples, 26 were found to be positive for bat coronavirus HKU10 (BtCoV HKU10). New habitats of BtCoV HKU10 were found in the Yunnan, Guangxi, and Hainan Provinces of China, and Louang Namtha Province in Laos. In addition to H. pomona, BtCoV HKU10 variants were found circulating in Aselliscus stoliczkanus and Hipposideros larvatus. We sequenced full-length genomes of 17 newly discovered BtCoV HKU10 strains and compared them with previously published sequences. Our results revealed a much higher genetic diversity of BtCoV HKU10, particularly in spike genes and accessory genes. Besides the two previously reported lineages, we found six novel lineages in their new habitats, three of which were located in Yunnan province. The genotypes of these viruses are closely related to sampling locations based on polyproteins, and correlated to bat species based on spike genes. Combining phylogenetic analysis, selective pressure, and molecular-clock calculation, we demonstrated that Yunnan bats harbor a gene pool of BtCoV HKU10, with H. pomona as a natural reservoir. The cell tropism test using spike-pseudotyped lentivirus system showed that BtCoV HKU10 could enter cells from human and bat, suggesting a potential interspecies spillover. Continuous studies on these bat coronaviruses will expand our understanding of the evolution and genetic diversity of coronaviruses, and provide a prewarning of potential zoonotic diseases from bats.
Subject(s)
Alphacoronavirus/genetics , Chiroptera/virology , Alphacoronavirus/pathogenicity , Animals , Base Sequence/genetics , Biological Evolution , China , Chiroptera/genetics , Coronavirus/genetics , Coronavirus/pathogenicity , Coronavirus Infections/virology , Evolution, Molecular , Genetic Variation/genetics , Genome, Viral/genetics , Genotype , Phylogeny , Sequence Analysis, DNA/methods , Viral Proteins/geneticsABSTRACT
BACKGROUND: Strategies are urgently needed to mitigate the risk of zoonotic disease emergence in southern China, where pathogens with zoonotic potential are known to circulate in wild animal populations. However, the risk factors leading to emergence are poorly understood, which presents a challenge in developing appropriate mitigation strategies for local communities. METHODS: Residents in rural communities of Yunnan, Guangxi and Guangdong provinces were recruited and enrolled in this study. Data were collected through ethnographic interviews and field observations, and thematically coded and analysed to identify both risk and protective factors for zoonotic disease emergence at the individual, community and policy levels. RESULTS: Eighty-eight ethnographic interviews and 55 field observations were conducted at nine selected sites. Frequent human-animal interactions and low levels of environmental biosecurity in local communities were identified as risks for zoonotic disease emergence. Policies and programmes existing in the communities provide opportunities for zoonotic risk mitigation. CONCLUSIONS: This study explored the relationship among zoonotic risk and human behaviour, environment and policies in rural communities in southern China. It identifies key behavioural risk factors that can be targeted for development of tailored risk-mitigation strategies to reduce the threat of novel zoonoses.
Subject(s)
Animals, Wild/virology , Communicable Diseases, Emerging/transmission , Coronavirus Infections/transmission , Disease Outbreaks/prevention & control , Pneumonia, Viral/transmission , Rural Population , Virus Diseases/transmission , Zoonoses/transmission , Adolescent , Adult , Animals , Betacoronavirus , COVID-19 , China/epidemiology , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Female , Health Knowledge, Attitudes, Practice , Humans , Interviews as Topic , Male , Middle Aged , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Qualitative Research , Risk Factors , SARS-CoV-2 , Severe Acute Respiratory Syndrome , Virus Diseases/epidemiology , Young Adult , Zoonoses/epidemiology , Zoonoses/virologyABSTRACT
BACKGROUND: Cynomolgus disease models that are similar to the preclinical stage of human type 2 diabetes mellitus (T2DM) were established by feeding middle-aged cynomolgus monkeys different high energy diets to study the differential expression of diabetes-related genes. METHODS: A total of 36 male monkeys were randomly divided into four groups and fed human diets with high sugar, high fat, double high sugar and fat, and a normal diet. The preclinical diabetes phase was determined by monitoring the metabolic characteristic indices and the results of oral glucose tolerance tests (OGTT). The mRNA expression of 45 diabetes-related genes in peripheral blood leukocytes was analyzed using real-time PCR. RESULTS: A total of 22, 25, and 21 genes were significantly up-regulated (P < 0.05) and 5, 7, and 5 genes were significantly down-regulated (P < 0.05) in the above three induced groups, respectively, compared with the control group. Of the 45 tested genes, the expression profiles of 21 genes were consistent. Most of the expression levels in the double high sugar-and-fat individuals were slightly lower than those in the high glucose and high fat groups, although the expression patterns of the three groups were essentially similar. CONCLUSION: The different high energy diets all induced diabetes and shared some phenotypic properties with human T2DM. Most of the expression patterns of the related genes were identical. The gene expression profiles could be used as references for the study of early diagnostic indicators and T2DM pathogenesis.
ABSTRACT
BACKGROUND: Histone deacetylases (HDACs) are promising therapeutic targets for the treatment of cancer, diabetes and other human diseases. HDAC inhibitors, as a new class of potential therapeutic agents, have attracted a great deal of interest for both research and clinical applications. Increasing efforts have been focused on the discovery of HDAC inhibitors and some HDAC inhibitors have been approved for use in cancer therapy. However, most HDAC inhibitors, including the clinically approved agents, do not selectively inhibit the deacetylase activity of class I and II HDAC isforms, and many suffer from metabolic instability. This study aims to identify new HDAC inhibitors by using a high-throughput virtual screening approach. METHODS: An integration of in silico virtual screening and in vitro experimental validation was used to identify novel HDAC inhibitors from a chemical database. RESULTS: A virtual screening workflow for HDAC inhibitors were created by integrating ligand- and receptor- based virtual screening methods. Using the virtual screening workflow, 22 hit compounds were selected and further tested via in vitro assays. Enzyme inhibition assays showed that three of the 22 compounds had HDAC inhibitory properties. Among these three compounds, ZINC12555961 significantly inhibited HDAC activity. Further in vitro experiments indicated that ZINC12555961 can selectively inhibit proliferation and promote apoptosis of cancer cells. CONCLUSIONS: In summary, our study presents three new and potent HDAC inhibitors and one of these HDAC inhibitors shows anti-proliferative and apoptosis-inducing activity against various cancer cell lines. These results suggest that the developed virtual screening workflow can provide a useful source of information for the screening and validation of new HDAC inhibitors. The new-found HDAC inhibitors are worthy to further and more comprehensive investigations.
Subject(s)
Drug Design , Histone Deacetylase Inhibitors/chemistry , Histone Deacetylase Inhibitors/pharmacology , User-Computer Interface , Apoptosis/drug effects , Apoptosis/physiology , Drug Evaluation, Preclinical/methods , Drug Evaluation, Preclinical/standards , Hep G2 Cells , Humans , Reproducibility of ResultsABSTRACT
Chinese chiropterologists have made significant improvements into research on bat taxonomy and distribution. Overall, scholars recorded 6 new species of bats, alongside 11 species recorded species in the Chinese Mainland and 4 new bat species of Murina in Taiwan. Chinese chiropterologists intensively cooperated with the international experts on bats, and adopted several new, multidisciplinary methods to carry out their studies. Likewise, in China, an increased awareness of bat conservation has been growing. While publications on Chiroptera are continuing to increase increased in China, the methodology of these studies remains to be further developed in hopes of revealing the new and cryptic bat species. Considering the vast territory of China and the migrational habit of bats, we expect that with more refined methodology, more new species of bats and their distributions may be uncovered in the near future. Concurrently, it is important to reexamine the known species by the new taxonomic methods and fauna analysis through which the distribution and subdivision of bats can be updated. Additionally, an international platform for exchanging information of bats needs to be established to enhance the academic cooperation for bat researches. It is highly possible that China will soon become an important research center on taxonomy, distribution, phylogenetics and diversity evolution of Chiroptera, especially as Chinese researchers continues create new knowledge for bats at the α, ß and γ taxonomic levels.
Subject(s)
Chiroptera/classification , Achievement , Animals , ChinaABSTRACT
Grooming behavior is evolved in animals in response to the costs associated with ectoparasites. In this study, ecotparasite densities and grooming behavior-including licking and scratching-of wild-caught lesser bamboo bat (Tylonycteris pachypus) and greater bamboo bat (T. robustula) were analyzed. The results indicated that both the frequencies and durations of licking were higher than those of scratching in both bat species, though T. pachypus licked more but scratched less than T. robustula. There were no difference in the durations of licking and scratching between the two bat species, and the durations and frequencies of grooming behavior of the two bat species were irrelevant with ectoparasite densities. These findings suggest that the grooming behavior of T. pachypus and T. robustula might be modulated by both the central control (programmed grooming) model and the peripheral stimulation (stimulus driven) model.
Subject(s)
Chiroptera/physiology , Chiroptera/parasitology , Host-Parasite Interactions , Parasites/physiology , Animals , GroomingABSTRACT
Here, we present our findings of free-flying echolocation calls of Himalayan swiftlets (Aerodramus brevirostris), which were recorded in Shenjing Cave, Hupingshan National Reserve, Shimen County, Hunan Province in June 2012, using Avisoft-UltraSoundGate 116(e). We noted that after foraging at dusk, the Himalayan swiftlets flew fast into the cave without clicks, and then slowed down in dark area in the cave, but with sounds. The echolocation sounds of Himalayan swiftlets are broadband, double noise burst clicks, separated by a short pause. The inter-pulse intervals between double clicks (99.3±3.86 ms)were longer than those within double clicks (6.6±0.42 ms) (P<0.01). With the exception of peak frequency, between 6.2±0.08 kHz and 6.2±0.10 kHz, (P>0.05) and pulse duration 2.9±0.12 ms, 3.2±0.17 ms, (P>0.05) between the first and second, other factors-maximum frequency, minimum frequency, frequency bandwidth, and power-were significantly different between the clicks. The maximum frequency of the first pulse (20.1±1.10 kHz) was higher than that of second (15.4±0.98 kHz) (P<0.01), while the minimum frequency of the first pulse (3.7±0.12 kHz) was lower than that of second (4.0±0.09 kHz) (P<0.05); resulting in the frequency bandwidth of the first pulse (16.5±1.17 kHz) longer than that of second (11.4±1.01 kHz) (P<0.01). The power of the first pulse (-32.5±0.60 dB) was higher than that of second (-35.2±0.94 dB) (P<0.05). More importantly, we found that Himalayan swiftlets emitted echolocation pulses including ultrasonic sound, with a maximum frequency reaching 33.2 kHz.
Subject(s)
Birds/physiology , Echolocation/physiology , Flight, Animal/physiology , Vocalization, Animal/physiology , Animals , Sound , Sound Spectrography/methodsABSTRACT
Correlations of two species of gamasid mites (Macronyssus pararadovskyi and M. radovskyi) and their bat hosts (Tylonycteris pachypus and T. robustula) were studied by field surveys and indoor behavioral experiments. The wild data indicated that mite load was positively correlated with body condition index of female T. pachypus hosts (Spearman: r (s)=0.55, P<0.01, n=24). Whereas, mite loads had no correlation with body condition indexes of male T. pachypus and all T. robustula hosts (P>0.05). Indoor original host infection showed that mites preferred male T. pachypus and T. robustula hosts. The infection percentages on male hosts were significantly higher than those on female hosts [T. pachypus: male (58±12)%, female (42±12)%, (t=-3.6, df=31, P<0.01); T. robustula: male (63±11)%, female (37±11)%, (t=-6.1, df=26, P<0.001)]. Using M. pararadovskyi (original host T. pachypus) to across infect T. pachypus and T. robustula, we found that mites significantly preferred the original host (t=9.1, df=29, P<0.001). The infection percentages of T. pachypus, and T. robustula were (71±13)% and (29±13)%, respectively. Our results indicated that mite loads of the two bat species were not correlated with body condition indexes of hosts. However, these mites presented different host sexual preferences, and the mites of T. pachypus presented specific host species preferences.
Subject(s)
Chiroptera/parasitology , Host Specificity , Mites/physiology , Animals , Chiroptera/classification , Female , Male , Sex Factors , Species Specificity , Time FactorsABSTRACT
The morphology and diet characteristics of three Myotis species roosting in the same cave were studied in Anlong County, Guizhou from September to November 2005. The three mouse-eared bats were the Chinese water myotis (Myotis laniger) "body mass: (4.46±0.53) g, forearm: (34.63±1.45 mm)", fringed long-footed myotis (Myotis fimbriatus) "body mass: (5.15±1.76) g, forearm: (35.20±1.07) mm" and szechwan myotis (Myotis altarium) "body mass: (10.94±0.87) g, forearm: (45.21±1.15) mm". There were significant differences in the body masses of the three species. The forearm length of M. altarium was significantly longer than the other two species. M. laniger preyed mostly on dipsters and their larvae (79.7% in volume and 100% in frequency, Diptera). M. fimbriatus preyed mostly on dipsters and small beetles (59.6% and 91.3%, Diptera; 28.8% and 80.1%, Coleoptera). The prey of M. altarium was mostly ground-dwelling beetles (80.8% and 100%, Carabidae and Silphidae, Coleoptera). These dietary examinations indicate that the three species are highly adapted to different foraging habitats. Our work suggests that the spatial differences in foraging niches and trophic resource partitioning represent the major mechanism behind the levels of co-existence seen in this particular bat community.
Subject(s)
Chiroptera/physiology , Predatory Behavior/physiology , Animals , Coleoptera , EcosystemABSTRACT
We investigated food (insect) availability in foraging areas utilized by the long-fingered bat Miniopterus fuliginosus using light traps, fish netting and fecal analysis. The dominant preys of M. fuliginosus were Lepidoptera (55%, by volume percent) and Coleoptera (38%) of a relatively large body size. M. fuliginosus has relatively long, narrow wings and a wing span of 6.58+/-0.12 and high wing loading of 9.85+/-0.83 N/m2. The echolocation calls of free flying M. fuliginosus were FM signals, with a pulse duration of 1.45+/-0.06 ms, interpulse interval of 63.08+/-21.55 ms, and low dominant frequency of 44.50+/-2.26 kHz. This study shows that the morphological characteristics and echolocation calls of long-fingered bats are closely linked to their predatory behavior.