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Satoshi D Ohdachi - One of the best experts on this subject based on the ideXlab platform.
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genetic diversity and phylogeography of thottapalayam thottimvirus hantaviridae in asian house shrew suncus murinus in eurasia
Frontiers in Cellular and Infection Microbiology, 2020Co-Authors: Fuka Kikuchi, Satoshi D Ohdachi, Masaharu Motokawa, Takamichi Jogahara, Saw Bawm, Keita Aoki, Kimiyuki Tsuchiya, Nguyễn Trường Sơn, Kyaw San Lin, Thida Lay ThweAbstract:Murid and cricetid rodents were previously believed to be the principal reservoir hosts of hantaviruses. Recently, however, multiple newfound hantaviruses have been discovered in Shrews, moles, and bats, suggesting a complex evolutionary history. Little is known about the genetic diversity and geographic distribution of the prototype shrew-borne hantavirus, Thottapalayam thottimvirus (TPMV), carried by the Asian house shrew (Suncus murinus), which is widespread in Asia, Africa, and the Middle East. Comparison of TPMV genomic sequences from two Asian house Shrews captured in Myanmar and Pakistan with TPMV strains in GenBank revealed that the Myanmar TPMV strain (H2763) was closely related to the prototype TPMV strain (VRC66412) from India. In the L-segment tree, on the other hand, the Pakistan TPMV strain (PK3629) appeared to be the most divergent, followed by TPMV strains from Nepal, then the Indian-Myanmar strains, and finally TPMV strains from China. The Myanmar strain of TPMV showed sequence similarity of 79.3-96.1% at the nucleotide level, but the deduced amino acid sequences showed a high degree of conservation of more than 94% with TPMV strains from Nepal, India, Pakistan, and China. Cophylogenetic analysis of host cytochrome b and TPMV strains suggested that the Pakistan TPMV strain was mismatched. Phylogenetic trees, based on host cytochrome b and cytochrome c oxidase subunit I genes of mitochondrial DNA, and on host recombination activating gene 1 of nuclear DNA, suggested that the Asian house shrew and Asian highland shrew (Suncus montanus) comprised a species complex. Overall, the geographic-specific clustering of TPMV strains in Asian countries suggested local host-specific adaptation. Additional in-depth studies are warranted to ascertain if TPMV originated in Asian house Shrews on the Indian subcontinent.
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acoustic emissions of sorex unguiculatus mammalia soricidae assessing the echo based orientation hypothesis
Ecology and Evolution, 2019Co-Authors: Lida Sanchez, Satoshi D Ohdachi, Atsushi Kawahara, Lazaro M Echeniquediaz, Shinichiro Maruyama, Masakado KawataAbstract:Shrew species have been proposed to utilize an echo-based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when Shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long-clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short-click, noisy, and different types of tonal calls in the audible-to-ultrasonic frequency range were recorded under all experimental conditions. The results indicated that Shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, Shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, that is, plants and acrylic barriers. The vocalizations emitted at short inter-pulse intervals could not be observed when Shrews approached these obstacles. These results are consistent with the echo-based orientation hypothesis according to which Shrews use a simple echo-orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis.
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re evaluation of the phylogeny based on mitochondrial cytochrome b gene in the house shrew suncus murinus s montanus species complex with special reference to yemen and myanmar populations
Journal of Wildlife and Biodiversity, 2017Co-Authors: Satoshi D Ohdachi, Satoru Arai, Gohta Kinoshita, Abdul Karim Nasher, Takahiro Yonezawa, Fuka KikuchiAbstract:The house shrew (Suncus murinus-S. montanus species complex) is considered to have been unintentionally introduced by humans from their original range to other regions around the Indian Ocean and neighboring seas, but this has yet not fully been investigated. A phylogenetic tree and haplotype network were reconstructed based on the mitochondrial cytochrome b gene nucleotide sequences (1140 bp) of 179 individuals of house Shrews from 46 localities in southern East Asia, Southeast Asia, West Asia, and islands in the western Indian Ocean. There was small genetic variation among Shrews in Japan (Okinawa), southern China, Vietnam, and insular Southeast Asia. However, the shrew populations in Myanmar and Sri Lanka showed of a variety of different haplotypes. In the region of the western Indian Ocean, three interesting findings were obtained. First, the Shrews on Zanzibar Island (Tanzania) shared same haplotype as those in southwestern Iran, and the haplotype was close to a group in Pakistan, despite these three regions being distantly located. Second, inferring from the haplotype network, it was suggests that the Shrews in Yemen might have derived from Madagascar/Comoros populations. Third, the Shrews on Reunion Island were genetically different from other populations around the western Indian Ocean but closer to Malaysia and Myanmar populations. Thus, the present study demonstrates that there have been dynamic immigration/emigration processes in the house Shrews, especially for those around the western Indian Ocean. In addition, the house Shrews in Myanmar may include several different species.
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intraspecific phylogeny of the house Shrews suncus murinus s montanus species complex based on the mitochondrial cytochrome b gene
Mammal Study, 2016Co-Authors: Satoshi D Ohdachi, Satoru Arai, Gohta Kinoshita, Masaharu Motokawa, Takamichi Jogahara, Son Truong Nguyen, Hitoshi Suzuki, Ken Katakura, Saw Bawm, Thida Lay ThweAbstract:Abstract. A phylogenetic tree was reconstructed based on the mitochondrial cytochrome b gene nucleotide sequences of 169 individuals of house Shrews (Suncus murinus and S. montanus) from 44 localities in East Asia, Southeast Asia, West Asia, and islands in the western Indian Ocean. Shrews from China (Zhejiang), Japan (Okinawa), Vietnam, and Indonesia (Java) formed a monophyletic group with less genetic variation. Therefore, the Shrews of these regions appeared to have originated from one or a few localities. Contrary to this, Shrews from Sri Lanka, Myanmar, and Pakistan consisted of several haplogroups. This finding suggests immigration movements to these areas. Fascinating findings were also obtained concerning the islands in the western Indian Ocean. First, Shrews on Zanzibar Island (Tanzania) had almost the same haplotype as those in southwestern Iran. Therefore, the house shrew in Zanzibar may have immigrated from Iran (or vice versa). Second, Shrews from Madagascar and Grande Comore Island shared the...
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top down cascade effects of the long clawed shrew sorex unguiculatus on the soil invertebrate community in a cool temperate forest
Mammal Study, 2016Co-Authors: Tomoyuki Namba, Satoshi D OhdachiAbstract:Abstract. In a soil ecosystem, bottom-up control is generally considered more influential than topdown control, although some empirical studies have suggested that predators have a trophic cascade effect on soil animals at lower trophic levels. In the present study, the effects of the long-clawed shrew, a mammalian predator at a high trophic level, on the soil invertebrate community and litter decomposition were investigated in a field experiment using enclosures. In the presence of the shrew, the population densities of earthworms, isopods and spiders tended to decrease, whereas that of large springtails and centipedes appeared to increase. This result might have been caused by the shrew's direct predation on the former invertebrates and the release from predation by spiders on springtails. The reason of the increase of centipedes was unknown. Shrew had no effects on litter decomposition rates both by litter trap analysis and litter-bag test. The top-down effects of Shrews on litter decomposition might h...
Sophie Von Merten - One of the best experts on this subject based on the ideXlab platform.
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shrew twittering call rate is high in novel environments a lab study
Mammal Research, 2020Co-Authors: Sophie Von Merten, Björn Martin SiemersAbstract:Shrews use several different call types for communication. In previous studies, two call types have been additionally associated with a possible function for echolocation: ultrasonic click-like emissions and sonic twittering calls. There is anecdotal evidence that the rate of shrew twittering calls is high in unfamiliar environments and lower in familiar ones. Here we quantitatively tested this assumption for the first time. In a simple laboratory experiment, we confronted three different shrew species with environments of different degrees of novelty. We could show that the twittering call rate indeed decreased with increasing familiarity with the environment. In a separate experiment, we tested if Shrews would increase twittering call rate after a stressful event, which they did not. The finding of an increased call rate inside a novel environment that is not caused by stress is in line with the hypothesis of a very basic echolocation-like system in Shrews, as also bats increase their echolocation call rate in novel environments. However, it is not in full agreement with the hypothesis that twittering in Shrews mainly has a function for communication, as in territorial signalling, call rates are usually higher in familiar than in unfamiliar environments. Call rates did not change after a small structural alteration inside the familiar environment, suggesting that Shrews use their twittering calls not for a fine-tuned echolocation like bats, but rather a coarse acoustic orientation in their surroundings (‘echo-orientation’). Certainly, echo-orientation and communication might be two parallel, non-mutually exclusive functions of shrew twittering.
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acoustic species identification of Shrews twittering calls for monitoring
Ecological Informatics, 2015Co-Authors: Björn Martin Siemers, Sandor Zsebők, David Czaban, Janos Farkas, Sophie Von MertenAbstract:The acoustic signals of Shrews (Soricidae) are largely understudied. As Shrews are very vocal animals it may be feasible to use acoustic methods in field studies to assess ecological and behavioral data. In this study, we present the first detailed analysis of the twittering calls of six Central European shrew species (Sorex minutus, Sorex araneus, Neomys fodiens, Neomys anomalus, Crocidura russula and Crocidura leucodon). The analysis is based on over 6000 recorded calls from 121 individuals. Our results indicate that there is a large inter-individual variance and a large inter-specific overlap in the acoustic parameters of the calls. Each species uses a large spectral variety of calls without clear species specific call types. A species identification using the Support Vector Machine method on six species shows 66.2% accuracy; however, a pairwise comparison indicates accuracy between 68.5 and 97.3%. We propose to use acoustic monitoring of Shrews in comparative studies to estimate the overall shrew activity. Moreover we suggest using the acoustic identification method in areas with few shrew species where the accuracy of the technique can be eligible.
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Why do Shrews twitter? Communication or simple echo-based orientation
Biology Letters, 2009Co-Authors: Björn Martin Siemers, Grit Schauermann, Hendrik Turni, Sophie Von MertenAbstract:Shrews are very vocal animals. We tested behaviourally whether the high-pitched laryngeal ‘twittering’ calls of as-yet unclear function serve for communication or echo-based orientation. We used a representative species from each of the two largest phylogenetic groups of Shrews. In both species, experimental manipulation of substrate density, but not of the likelihood of conspecific presence, affected the Shrews' call rate when exploring an unknown environment. This adaptation of call rate to the degree of habitat clutter parallels bat echolocation and suggests that Shrews may use the echoes and reverberations of their calls for identifying routes through their habitat or for probing habitat type. To assess the acoustic feasibility of shrew echo orientation, we ensonified shrew habitats in the field with an ‘artificial shrew’ (small speaker mounted close to a sensitive microphone). The data showed that shrew-like calls can indeed yield echo scenes useful for habitat assessment at close range, but beyond the range of the Shrews' vibrissae.
Satoru Arai - One of the best experts on this subject based on the ideXlab platform.
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re evaluation of the phylogeny based on mitochondrial cytochrome b gene in the house shrew suncus murinus s montanus species complex with special reference to yemen and myanmar populations
Journal of Wildlife and Biodiversity, 2017Co-Authors: Satoshi D Ohdachi, Satoru Arai, Gohta Kinoshita, Abdul Karim Nasher, Takahiro Yonezawa, Fuka KikuchiAbstract:The house shrew (Suncus murinus-S. montanus species complex) is considered to have been unintentionally introduced by humans from their original range to other regions around the Indian Ocean and neighboring seas, but this has yet not fully been investigated. A phylogenetic tree and haplotype network were reconstructed based on the mitochondrial cytochrome b gene nucleotide sequences (1140 bp) of 179 individuals of house Shrews from 46 localities in southern East Asia, Southeast Asia, West Asia, and islands in the western Indian Ocean. There was small genetic variation among Shrews in Japan (Okinawa), southern China, Vietnam, and insular Southeast Asia. However, the shrew populations in Myanmar and Sri Lanka showed of a variety of different haplotypes. In the region of the western Indian Ocean, three interesting findings were obtained. First, the Shrews on Zanzibar Island (Tanzania) shared same haplotype as those in southwestern Iran, and the haplotype was close to a group in Pakistan, despite these three regions being distantly located. Second, inferring from the haplotype network, it was suggests that the Shrews in Yemen might have derived from Madagascar/Comoros populations. Third, the Shrews on Reunion Island were genetically different from other populations around the western Indian Ocean but closer to Malaysia and Myanmar populations. Thus, the present study demonstrates that there have been dynamic immigration/emigration processes in the house Shrews, especially for those around the western Indian Ocean. In addition, the house Shrews in Myanmar may include several different species.
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intraspecific phylogeny of the house Shrews suncus murinus s montanus species complex based on the mitochondrial cytochrome b gene
Mammal Study, 2016Co-Authors: Satoshi D Ohdachi, Satoru Arai, Gohta Kinoshita, Masaharu Motokawa, Takamichi Jogahara, Son Truong Nguyen, Hitoshi Suzuki, Ken Katakura, Saw Bawm, Thida Lay ThweAbstract:Abstract. A phylogenetic tree was reconstructed based on the mitochondrial cytochrome b gene nucleotide sequences of 169 individuals of house Shrews (Suncus murinus and S. montanus) from 44 localities in East Asia, Southeast Asia, West Asia, and islands in the western Indian Ocean. Shrews from China (Zhejiang), Japan (Okinawa), Vietnam, and Indonesia (Java) formed a monophyletic group with less genetic variation. Therefore, the Shrews of these regions appeared to have originated from one or a few localities. Contrary to this, Shrews from Sri Lanka, Myanmar, and Pakistan consisted of several haplogroups. This finding suggests immigration movements to these areas. Fascinating findings were also obtained concerning the islands in the western Indian Ocean. First, Shrews on Zanzibar Island (Tanzania) had almost the same haplotype as those in southwestern Iran. Therefore, the house shrew in Zanzibar may have immigrated from Iran (or vice versa). Second, Shrews from Madagascar and Grande Comore Island shared the...
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genetic diversity of artybash virus in the laxmann s shrew sorex caecutiens
Vector-borne and Zoonotic Diseases, 2016Co-Authors: Satoru Arai, Hae Ji Kang, Joseph A. Cook, Satoshi D Ohdachi, Liudmila N Yashina, Keiko Tanakataya, S A Abramov, Shigeru Morikawa, Nobuhiko Okabe, Kazunori OishiAbstract:Abstract Although based on very limited M and L segment sequences, Artybash virus (ARTV) was proposed previously as a unique hantavirus harbored by the Laxmann's shrew (Sorex caecutiens). To verify this conjecture, lung tissues from 68 Laxmann's Shrews, captured during 2006 to 2014 in eastern Siberia, Russia, and Hokkaido, Japan, were analyzed for ARTV RNA using reverse transcription polymerase chain reaction (RT-PCR). ARTV RNA was detected in six Laxmann's Shrews. Pairwise alignment and comparison of partial- and full-length S, M, and L segment sequences from these Laxmann's Shrews, as well as phylogenetic analyses, using maximum likelihood and Bayesian methods indicated that ARTV was distinct from other soricine shrew-borne hantaviruses and representative hantaviruses harbored by rodents, moles, and bats. Taxonomic identity of the ARTV-infected Laxmann's Shrews was confirmed by full-length cytochrome b mitochondrial DNA sequence analysis. Our data indicate that the hantavirus previously known as Amga vi...
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genetic diversity and phylogeography of seewis virus in the eurasian common shrew in finland and hungary
Virology Journal, 2009Co-Authors: Hae Ji Kang, Satoru Arai, Andrew G. Hope, Joseph A. Cook, Jin-won Song, Richard YanagiharaAbstract:Recent identification of a newfound hantavirus, designated Seewis virus (SWSV), in the Eurasian common shrew (Sorex araneus), captured in Switzerland, corroborates decades-old reports of hantaviral antigens in this shrew species from Russia. To ascertain the spatial or geographic variation of SWSV, archival liver tissues from 88 Eurasian common Shrews, trapped in Finland in 1982 and in Hungary during 1997, 1999 and 2000, were analyzed for hantavirus RNAs by reverse transcription-polymerase chain reaction. SWSV RNAs were detected in 12 of 22 (54.5%) and 13 of 66 (19.7%) Eurasian common Shrews from Finland and Hungary, respectively. Phylogenetic analyses of S- and L-segment sequences of SWSV strains, using maximum likelihood and Bayesian methods, revealed geographic-specific genetic variation, similar to the phylogeography of rodent-borne hantaviruses, suggesting long-standing hantavirus-host co-evolutionary adaptation.
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molecular phylogeny of a newfound hantavirus in the japanese shrew mole urotrichus talpoides
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Satoru Arai, Hae Ji Kang, Satoshi D Ohdachi, Nobuhiko Okabe, Mitsuhiko Asakawa, Gabor Mocz, Jiro Arikawa, Richard YanagiharaAbstract:Recent molecular evidence of genetically distinct hantaviruses in Shrews, captured in widely separated geographical regions, corroborates decades-old reports of hantavirus antigens in shrew tissues. Apart from challenging the conventional view that rodents are the principal reservoir hosts, the recently identified soricid-borne hantaviruses raise the possibility that other soricomorphs, notably talpids, similarly harbor hantaviruses. In analyzing RNA extracts from lung tissues of the Japanese shrew mole (Urotrichus talpoides), captured in Japan between February and April 2008, a hantavirus genome, designated Asama virus (ASAV), was detected by RT-PCR. Pairwise alignment and comparison of the S-, M-, and L-segment nucleotide and amino acid sequences indicated that ASAV was genetically more similar to hantaviruses harbored by Shrews than by rodents. However, the predicted secondary structure of the ASAV nucleocapsid protein was similar to that of rodent- and shrew-borne hantaviruses, exhibiting the same coiled-coil helix at the amino terminus. Phylogenetic analyses, using the maximum-likelihood method and other algorithms, consistently placed ASAV with recently identified soricine shrew-borne hantaviruses, suggesting a possible host-switching event in the distant past. The discovery of a mole-borne hantavirus enlarges our concepts about the complex evolutionary history of hantaviruses.
Richard Yanagihara - One of the best experts on this subject based on the ideXlab platform.
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expanded host diversity and geographic distribution of hantaviruses in sub saharan africa
Journal of Virology, 2014Co-Authors: Hae Ji Kang, William T Stanley, Jacob A Esselstyn, Richard YanagiharaAbstract:The recent discovery of hantaviruses in Shrews and bats in West Africa suggests that other genetically distinct hantaviruses exist in East Africa. Genetic and phylogenetic analyses of newfound hantaviruses, detected in archival tissues from the Geata mouse shrew (Myosorex geata) and Kilimanjaro mouse shrew ( Myosorex zinki) captured in Tanzania, expands the host diversity and geographic distribution of hantaviruses and suggests that ancestral Shrews and/or bats may have served as the original mammalian hosts of primordial hantaviruses.
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DISPATCHES
2013Co-Authors: In Northern, Joseph A. Cook, Shannon N. Bennett, Cheryl A. Parmenter, Vivek R. Nerurkar, Terry L. Yates, Richard YanagiharaAbstract:Phylogenetic analyses, based on partial medium- and large-segment sequences, support an ancient evolutionary origin of a genetically distinct hantavirus detected by reverse transcription–PCR in tissues of northern short-tailed Shrews (Blarina brevicauda) captured in Minnesota in August 1998. To our knowledge, this is the fi rst evidence of hantaviruses harbored by Shrews in the Americas. Rodents and their ectoparasites serve as reservoirs and vectors of myriad viruses and other pathogenic microbes. In contrast, the role of insectivores (or soricomorphs) in the transmission and ecology of zoonoses is largely unknown. Because some soricomorphs share habitats with rodents, Shrews might also be involved in the maintenance of the enzootic cycle and contribute to the evolutionary history and genetic diversity of hantaviruses. Hantavirus antigens have been detected in the Eurasian common shrew (Sorex araneus), alpine shrew (Sorex alpinus), Eurasian water shrew (Neomys fodiens), and common mole (Talpa europea) in Russia and the former Yugoslavia (1–3). More than 20 years ago, when Prospect Hill virus was discovered in meadow voles (Microtus pennsylvanicus) captured in Frederick, Maryland, USA, serologic evidence suggestive of hantavirus infection was found in the northern short-tailed shrew (Blarina brevicauda) (4). However, virus isolation attempts were unsuccessful, and molecular tools such as PCR were unavailable. Empowered by robust gene-amplification techniques and the complete genome of Thottapalayam virus (TPMV) isolated from the Asian house shrew (Suncus murinus) (5,6), we have identified a genetically distinct hantavirus in the northern shorttailed shrew
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genetic diversity and phylogeography of seewis virus in the eurasian common shrew in finland and hungary
Virology Journal, 2009Co-Authors: Hae Ji Kang, Satoru Arai, Andrew G. Hope, Joseph A. Cook, Jin-won Song, Richard YanagiharaAbstract:Recent identification of a newfound hantavirus, designated Seewis virus (SWSV), in the Eurasian common shrew (Sorex araneus), captured in Switzerland, corroborates decades-old reports of hantaviral antigens in this shrew species from Russia. To ascertain the spatial or geographic variation of SWSV, archival liver tissues from 88 Eurasian common Shrews, trapped in Finland in 1982 and in Hungary during 1997, 1999 and 2000, were analyzed for hantavirus RNAs by reverse transcription-polymerase chain reaction. SWSV RNAs were detected in 12 of 22 (54.5%) and 13 of 66 (19.7%) Eurasian common Shrews from Finland and Hungary, respectively. Phylogenetic analyses of S- and L-segment sequences of SWSV strains, using maximum likelihood and Bayesian methods, revealed geographic-specific genetic variation, similar to the phylogeography of rodent-borne hantaviruses, suggesting long-standing hantavirus-host co-evolutionary adaptation.
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molecular phylogeny of a newfound hantavirus in the japanese shrew mole urotrichus talpoides
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Satoru Arai, Hae Ji Kang, Satoshi D Ohdachi, Nobuhiko Okabe, Mitsuhiko Asakawa, Gabor Mocz, Jiro Arikawa, Richard YanagiharaAbstract:Recent molecular evidence of genetically distinct hantaviruses in Shrews, captured in widely separated geographical regions, corroborates decades-old reports of hantavirus antigens in shrew tissues. Apart from challenging the conventional view that rodents are the principal reservoir hosts, the recently identified soricid-borne hantaviruses raise the possibility that other soricomorphs, notably talpids, similarly harbor hantaviruses. In analyzing RNA extracts from lung tissues of the Japanese shrew mole (Urotrichus talpoides), captured in Japan between February and April 2008, a hantavirus genome, designated Asama virus (ASAV), was detected by RT-PCR. Pairwise alignment and comparison of the S-, M-, and L-segment nucleotide and amino acid sequences indicated that ASAV was genetically more similar to hantaviruses harbored by Shrews than by rodents. However, the predicted secondary structure of the ASAV nucleocapsid protein was similar to that of rodent- and shrew-borne hantaviruses, exhibiting the same coiled-coil helix at the amino terminus. Phylogenetic analyses, using the maximum-likelihood method and other algorithms, consistently placed ASAV with recently identified soricine shrew-borne hantaviruses, suggesting a possible host-switching event in the distant past. The discovery of a mole-borne hantavirus enlarges our concepts about the complex evolutionary history of hantaviruses.
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Phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) and dusky shrew (Sorex monticolus) in the United States.
The American Journal of Tropical Medicine and Hygiene, 2008Co-Authors: Satoru Arai, Andrew G. Hope, Joseph A. Cook, Jin-won Song, Shannon N. Bennett, Laarni Sumibcay, Cheryl A. Parmenter, Vivek R. Nerurkar, Terry L. Yates, Richard YanagiharaAbstract:A limited search for hantaviruses in lung and liver tissues of Sorex Shrews (family Soricidae, subfamily Soricinae) revealed phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) from New Mexico and Colorado. The discovery of these shrew-borne hantaviruses, named Ash River virus and Jemez Springs virus, respectively, challenges the long-held dogma that rodents are the sole reservoir hosts and forces a re-examination of their co-evolutionary history. Also, studies now underway are aimed at clarifying the epizootiology and pathogenicity of these new members of the genus Hantavirus.
Björn Martin Siemers - One of the best experts on this subject based on the ideXlab platform.
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shrew twittering call rate is high in novel environments a lab study
Mammal Research, 2020Co-Authors: Sophie Von Merten, Björn Martin SiemersAbstract:Shrews use several different call types for communication. In previous studies, two call types have been additionally associated with a possible function for echolocation: ultrasonic click-like emissions and sonic twittering calls. There is anecdotal evidence that the rate of shrew twittering calls is high in unfamiliar environments and lower in familiar ones. Here we quantitatively tested this assumption for the first time. In a simple laboratory experiment, we confronted three different shrew species with environments of different degrees of novelty. We could show that the twittering call rate indeed decreased with increasing familiarity with the environment. In a separate experiment, we tested if Shrews would increase twittering call rate after a stressful event, which they did not. The finding of an increased call rate inside a novel environment that is not caused by stress is in line with the hypothesis of a very basic echolocation-like system in Shrews, as also bats increase their echolocation call rate in novel environments. However, it is not in full agreement with the hypothesis that twittering in Shrews mainly has a function for communication, as in territorial signalling, call rates are usually higher in familiar than in unfamiliar environments. Call rates did not change after a small structural alteration inside the familiar environment, suggesting that Shrews use their twittering calls not for a fine-tuned echolocation like bats, but rather a coarse acoustic orientation in their surroundings (‘echo-orientation’). Certainly, echo-orientation and communication might be two parallel, non-mutually exclusive functions of shrew twittering.
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acoustic species identification of Shrews twittering calls for monitoring
Ecological Informatics, 2015Co-Authors: Björn Martin Siemers, Sandor Zsebők, David Czaban, Janos Farkas, Sophie Von MertenAbstract:The acoustic signals of Shrews (Soricidae) are largely understudied. As Shrews are very vocal animals it may be feasible to use acoustic methods in field studies to assess ecological and behavioral data. In this study, we present the first detailed analysis of the twittering calls of six Central European shrew species (Sorex minutus, Sorex araneus, Neomys fodiens, Neomys anomalus, Crocidura russula and Crocidura leucodon). The analysis is based on over 6000 recorded calls from 121 individuals. Our results indicate that there is a large inter-individual variance and a large inter-specific overlap in the acoustic parameters of the calls. Each species uses a large spectral variety of calls without clear species specific call types. A species identification using the Support Vector Machine method on six species shows 66.2% accuracy; however, a pairwise comparison indicates accuracy between 68.5 and 97.3%. We propose to use acoustic monitoring of Shrews in comparative studies to estimate the overall shrew activity. Moreover we suggest using the acoustic identification method in areas with few shrew species where the accuracy of the technique can be eligible.
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Why do Shrews twitter? Communication or simple echo-based orientation
Biology Letters, 2009Co-Authors: Björn Martin Siemers, Grit Schauermann, Hendrik Turni, Sophie Von MertenAbstract:Shrews are very vocal animals. We tested behaviourally whether the high-pitched laryngeal ‘twittering’ calls of as-yet unclear function serve for communication or echo-based orientation. We used a representative species from each of the two largest phylogenetic groups of Shrews. In both species, experimental manipulation of substrate density, but not of the likelihood of conspecific presence, affected the Shrews' call rate when exploring an unknown environment. This adaptation of call rate to the degree of habitat clutter parallels bat echolocation and suggests that Shrews may use the echoes and reverberations of their calls for identifying routes through their habitat or for probing habitat type. To assess the acoustic feasibility of shrew echo orientation, we ensonified shrew habitats in the field with an ‘artificial shrew’ (small speaker mounted close to a sensitive microphone). The data showed that shrew-like calls can indeed yield echo scenes useful for habitat assessment at close range, but beyond the range of the Shrews' vibrissae.