In many vertebrates,the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right vis...In many vertebrates,the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right visual field specializes in the processing of information about conspecifics.This is referred to as hemispheric lateralization.But individuals that are too predictable in their response to predators could have reduced survival and we may expect selection for somewhat unpredictable responses.We studied hemispheric lateralization in yellow-bellied marmots Marmota flaviventer,a social rodent that falls prey to a variety of terrestrial and aerial predators.We first asked if they have lateralized responses to a predatory threat.We then asked if the eye that they used to assess risk influenced their perceptions of risk.We recorded the direction marmots were initially looking and then walked toward them until they fled.We recorded the distance that they responded to our experimental approach by looking,the eye with which they looked at us,and the distance at which they fled (i.e.,flight initiation distance;FID).We found that marmots had no eye preference with which they looked at an approaching threat.Furthermore,the population was not comprised of individuals that responded in consistent ways.However,we found that marmots that looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by the eye used to monitor the threat.These findings are consistent with selection to make prey less predictable for their predators,despite underlying lateralization.展开更多
Conservation of marmots, large ground-dwelling squirrels restricted to the northern hemisphere, was impacted by direct human activity through hunting or modifying ecosystem dynamics. Regulating human activities reduce...Conservation of marmots, large ground-dwelling squirrels restricted to the northern hemisphere, was impacted by direct human activity through hunting or modifying ecosystem dynamics. Regulating human activities reduced the threat of extinction. Climate change, an indirect human impact, threatens marmot survival through global warming and extreme weather events. Most marmot species occupy a harsh environment characterized by a short growing season and a long, cold season without food. Marmots cope with seasonality by hibernating. Their large size increases the efficiency of fat accumulation and its use as the sole energy source during hibernation. Marmot physiology is highly adapted to coping with low environmental temperatures;they are stressed by high heat loads. Global warming since the last ice age reduced the geographic distribution of some of the 15 species of marmots. Recent warming resulted in a movement upslope of their lower elevation boundary. This process likely will continue because warming is associated with drier unpalatable vegetation. Drought reduces reproduction and increases mortality;thus decreased summer rainfall in the montane environments where marmots live may cause local extinction. Snow cover, a major environmental factor, is essential to insulate hibernation burrows from low, stressful temperatures. However, prolonged vernal snow cover reduces reproduction and increases mortality. Montane areas currently lacking marmot populations because vernal snow cover persists beyond the time that marmots must begin foraging may become colonized if warming causes earlier snow melt. This benefit will be short-lived because decreased precipitation likely will result in unpalatable vegetation. Although some marmot populations are physiologically adapted to a warmer climate, global warming will increase too rapidly for any significant evolutionary response to dryness. The species that live in high, alpine meadows where tree and shrub invasions occur are most threatened with extinction. Captive breeding can preserve marmot species in the shortrun, but is impractical over the long-term. Widespread species are unlikely to be endangered in the foreseeable future, but local, low elevation populations will be lost.展开更多
Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by p...Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by prior work across taxa.However,how the sociality and connectivity of the group an individual resides in—their group social structure—relates to dispersal decisions has not been explored.We extend the social cohesion hypothesis to predict individuals residing in more social groups would remain at home,and we quantified the affiliative and agonistic social network structure of female yellow-bellied marmots(Marmota flaviventer),a facultatively social ground-dwelling squirrel,where about half of all females disperse.Using mixed-effects models,we found no support for the hypothesis that affiliative group structure explained any variation in a marmot’s decision to disperse.We did find marmots in groups with less agonistic centralization(around one or few individuals)were less likely to disperse.The former finding may result from limited ability to perceive group structure whereas the latter may reflect individuals in less agonistically centralized groups are less likely to be reproductively suppressed.These results suggest individual dispersal decisions are more impacted by individual sociality and not that of their social group.Thus,the social cohesion hypothesis may not scale to the level of the group.Further work is required to determine whether dispersal decisions in obligately social species are influenced by group social structure.展开更多
Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural...Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana)plague foci in China and covers more than 630000 km2.Akesai County in Gansu Province is a part of this natural focus of plague and was chosen as a study area.Our study used an ecological niche modeling(ENM)approach to predict the potential distribution of the Himalayan marmot.Environment and Disaster Monitor Satellite(HJ-1)data was used to investigate environment factors that affect plague host animal activity.Host animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100%subgroups.Areas with 80%-100%probability exhibited the greatest potential for the presence of Himalayan marmot.According to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.展开更多
Bocaparvovirus(BOV)is a genetically diverse group of DNA viruses and a possible cause of respiratory,enteric,and neurological diseases in humans and animals.Here,two highly divergent BOVs(tentatively named as Himalaya...Bocaparvovirus(BOV)is a genetically diverse group of DNA viruses and a possible cause of respiratory,enteric,and neurological diseases in humans and animals.Here,two highly divergent BOVs(tentatively named as Himalayan marmot BOV,HMBOV1 and HMBOV2)were identified in the livers and feces of wild Himalayan marmots in China,by viral metagenomic analysis.Five of 300 liver samples from Himalayan marmots were positive for HMBOV1 and five of 99 fecal samples from these animals for HMBOV2.Their nearly complete genome sequences are 4,672 and 4,887 nucleotides long,respectively,with a standard genomic organization and containing protein-coding motifs typical for BOVs.Based on their NS1,NP1,and VP1,HMBOV1 and HMBOV2 are most closely related to porcine BOV SX/1-2(approximately 77.0%/50.0%,50.0%/53.0%,and79.0%/54.0%amino acid identity,respectively).Phylogenetic analysis of these three proteins showed that HMBOV1 and HMBOV2 formed two distinctly independent branches in BOVs.According to these results,HMBOV1 and HMBOV2 are two different novel species in the Bocaparvovirus genus.Their identification expands our knowledge of the genetic diversity and evolution of BOVs.Further studies are needed to investigate their potential pathogenicity and their impact on Himalayan marmots and humans.展开更多
Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage...Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage, wind velocity, which are closely associated with global climate change, and to provide a reference for plague prevention and control. Methods: We conducted a regression analysis to find the possible climate factors associated with the density of Himalaya marmot, and analyzed the response characters of Himalayan marmot to climate change.Results: Dailyprecipitation days(>=0.1 mm) and sunshine percentage were significantly associated with thedensityofHimalayan marmot(p<0.01). Conclusion: Climate change was associated with the risk of plague. This phenomenon is valuable for Himalayan marmot and plague prevention. More studies are needed to understand the impact of climate change on Himalayan marmot and plague.展开更多
Inspired by recent environmental historical studies on animal extinctions and human-animal relations,this paper shifts scholarly attention from the plague-centered narrative of the great Pneumonic Plague Epidemics(191...Inspired by recent environmental historical studies on animal extinctions and human-animal relations,this paper shifts scholarly attention from the plague-centered narrative of the great Pneumonic Plague Epidemics(1910—11)to the fate of the plague host animals,Tarbagan marmots(Marmota sibirica>,and examines their ncar-extinction in Northwest Manchuria(Hulunbuir)from the 1900s to 1930s.Focusing on changing images of Tarbagan marmots from“inexpensive,”“sacred,”and“beneficial”in the pre-modem period to“valuable,”“dangerous,”and“noxious”in the early twentieth century,it argues that three interrelated factors:the international fur trade,pneumonic plagues,and environment changes together resulted in the“retreat of the marmots.”It also]uses this case study to help us better understand larger historical changes that occurred by contextualizing them in terms of human-marmot relations in Manchuria,China and beyond.展开更多
The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations of...The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations often sound“noisy”because vocal production systems are over-blown when animals are highly aroused.While much is known about the conditions under which animals produce vocalizations containing NLP and how species respond to them,there is little research about the heritability of such behavioral traits.Using the quantitative genetic animal model,we estimated the genetic basis of“noise”in alarm calls produced by females and found significant heritability in call entropy-our measure of the noisiness.About 9%of the variance in noisiness can be accounted for by genetic differences.Taken together,these findings suggest that the degree to which marmots produce noisy calls is modestly heritable and can be thus subject to further evolution via natural selection.展开更多
Climate change and its resulting effects on seasonality are known to alter a variety of animal behaviors including those related to foraging,phenology,and migration.Although many studies focus on the impacts of phenol...Climate change and its resulting effects on seasonality are known to alter a variety of animal behaviors including those related to foraging,phenology,and migration.Although many studies focus on the impacts of phenological changes on physiology or ftness enhancing behaviors,fewer have investigated the relationship between variation in weather and phenology on risk assessment.Fleeing from predators is an economic decision that incurs costs and benefts.As environmental conditions change,animals may face additional stressors that affect their decision to fee and infuence their ability to effectively assess risk.Flight initiation distance(FID)—the distance at which animals move away from threats—is often used to study risk assessment.FID varies due to both internal and external biotic and physical factors as well as anthropogenic activities.We asked whether variation in weather and phenology is associated with risk-taking in a population of yellow-bellied marmots(Marmota faviventer).As the air temperature increased marmots tolerated closer approaches,suggesting that they either perceived less risk or that their response to a threat was thermally compromised.The effect of temperature was relatively small and was largely dependent upon having a larger range in the full data set that permitted us to detect it.We found no effects of either the date that snow disappeared or July precipitation on marmot FID.As global temperatures continue to rise,rainfall varies more and drought becomes more common,understanding climate-related changes in how animals assess risk should be used to inform population viability models.展开更多
基金D.T.B.was supported by the National Science Foundation (grant 1557130). A.D.was an NSF REU fellow supported by DBI 1226713(to the Rocky Mountain Biological Laboratory).L.Y.was supported by China Scholarship Counsel and Peking University.
文摘In many vertebrates,the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right visual field specializes in the processing of information about conspecifics.This is referred to as hemispheric lateralization.But individuals that are too predictable in their response to predators could have reduced survival and we may expect selection for somewhat unpredictable responses.We studied hemispheric lateralization in yellow-bellied marmots Marmota flaviventer,a social rodent that falls prey to a variety of terrestrial and aerial predators.We first asked if they have lateralized responses to a predatory threat.We then asked if the eye that they used to assess risk influenced their perceptions of risk.We recorded the direction marmots were initially looking and then walked toward them until they fled.We recorded the distance that they responded to our experimental approach by looking,the eye with which they looked at us,and the distance at which they fled (i.e.,flight initiation distance;FID).We found that marmots had no eye preference with which they looked at an approaching threat.Furthermore,the population was not comprised of individuals that responded in consistent ways.However,we found that marmots that looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by the eye used to monitor the threat.These findings are consistent with selection to make prey less predictable for their predators,despite underlying lateralization.
文摘Conservation of marmots, large ground-dwelling squirrels restricted to the northern hemisphere, was impacted by direct human activity through hunting or modifying ecosystem dynamics. Regulating human activities reduced the threat of extinction. Climate change, an indirect human impact, threatens marmot survival through global warming and extreme weather events. Most marmot species occupy a harsh environment characterized by a short growing season and a long, cold season without food. Marmots cope with seasonality by hibernating. Their large size increases the efficiency of fat accumulation and its use as the sole energy source during hibernation. Marmot physiology is highly adapted to coping with low environmental temperatures;they are stressed by high heat loads. Global warming since the last ice age reduced the geographic distribution of some of the 15 species of marmots. Recent warming resulted in a movement upslope of their lower elevation boundary. This process likely will continue because warming is associated with drier unpalatable vegetation. Drought reduces reproduction and increases mortality;thus decreased summer rainfall in the montane environments where marmots live may cause local extinction. Snow cover, a major environmental factor, is essential to insulate hibernation burrows from low, stressful temperatures. However, prolonged vernal snow cover reduces reproduction and increases mortality. Montane areas currently lacking marmot populations because vernal snow cover persists beyond the time that marmots must begin foraging may become colonized if warming causes earlier snow melt. This benefit will be short-lived because decreased precipitation likely will result in unpalatable vegetation. Although some marmot populations are physiologically adapted to a warmer climate, global warming will increase too rapidly for any significant evolutionary response to dryness. The species that live in high, alpine meadows where tree and shrub invasions occur are most threatened with extinction. Captive breeding can preserve marmot species in the shortrun, but is impractical over the long-term. Widespread species are unlikely to be endangered in the foreseeable future, but local, low elevation populations will be lost.
基金supported by the Hamilton College Jeffery Fund Science Internship and the Rocky Mountain Biological Laboratorysupported by the University of California Los Angeles,American Society of Mammalogists,the Animal Behavior Society,and Rocky Mountain Biological Laboratory+1 种基金supported by the National Geographic Society,the University of California Los Angeles(Faculty Senate and Division of Life Sciences),an RMBL research fellowshipU.S.National Science Foundation(NSF IDBR-0754247 and DEB-1119660 and 1557130 to D.T.B.,as well as DBI 0242960,07211346,1226713,and 1755522 to RMBL).
文摘Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by prior work across taxa.However,how the sociality and connectivity of the group an individual resides in—their group social structure—relates to dispersal decisions has not been explored.We extend the social cohesion hypothesis to predict individuals residing in more social groups would remain at home,and we quantified the affiliative and agonistic social network structure of female yellow-bellied marmots(Marmota flaviventer),a facultatively social ground-dwelling squirrel,where about half of all females disperse.Using mixed-effects models,we found no support for the hypothesis that affiliative group structure explained any variation in a marmot’s decision to disperse.We did find marmots in groups with less agonistic centralization(around one or few individuals)were less likely to disperse.The former finding may result from limited ability to perceive group structure whereas the latter may reflect individuals in less agonistically centralized groups are less likely to be reproductively suppressed.These results suggest individual dispersal decisions are more impacted by individual sociality and not that of their social group.Thus,the social cohesion hypothesis may not scale to the level of the group.Further work is required to determine whether dispersal decisions in obligately social species are influenced by group social structure.
基金supported by the Special Grant for Prevention and Treatment of Infectious Diseases(Grant No.2008ZX10004-012)National Natural Science Foundation of China(Grant No.40871173)
文摘Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana)plague foci in China and covers more than 630000 km2.Akesai County in Gansu Province is a part of this natural focus of plague and was chosen as a study area.Our study used an ecological niche modeling(ENM)approach to predict the potential distribution of the Himalayan marmot.Environment and Disaster Monitor Satellite(HJ-1)data was used to investigate environment factors that affect plague host animal activity.Host animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100%subgroups.Areas with 80%-100%probability exhibited the greatest potential for the presence of Himalayan marmot.According to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.
基金funded by the Special National Project on Research and Development of Key Biosafety Technologies(2016YFC1201900)the National Natural Science Foundation of China(81290345)
文摘Bocaparvovirus(BOV)is a genetically diverse group of DNA viruses and a possible cause of respiratory,enteric,and neurological diseases in humans and animals.Here,two highly divergent BOVs(tentatively named as Himalayan marmot BOV,HMBOV1 and HMBOV2)were identified in the livers and feces of wild Himalayan marmots in China,by viral metagenomic analysis.Five of 300 liver samples from Himalayan marmots were positive for HMBOV1 and five of 99 fecal samples from these animals for HMBOV2.Their nearly complete genome sequences are 4,672 and 4,887 nucleotides long,respectively,with a standard genomic organization and containing protein-coding motifs typical for BOVs.Based on their NS1,NP1,and VP1,HMBOV1 and HMBOV2 are most closely related to porcine BOV SX/1-2(approximately 77.0%/50.0%,50.0%/53.0%,and79.0%/54.0%amino acid identity,respectively).Phylogenetic analysis of these three proteins showed that HMBOV1 and HMBOV2 formed two distinctly independent branches in BOVs.According to these results,HMBOV1 and HMBOV2 are two different novel species in the Bocaparvovirus genus.Their identification expands our knowledge of the genetic diversity and evolution of BOVs.Further studies are needed to investigate their potential pathogenicity and their impact on Himalayan marmots and humans.
基金The Basic Application Project of Qinghai Provincegrant number:2013-Z-747
文摘Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage, wind velocity, which are closely associated with global climate change, and to provide a reference for plague prevention and control. Methods: We conducted a regression analysis to find the possible climate factors associated with the density of Himalaya marmot, and analyzed the response characters of Himalayan marmot to climate change.Results: Dailyprecipitation days(>=0.1 mm) and sunshine percentage were significantly associated with thedensityofHimalayan marmot(p<0.01). Conclusion: Climate change was associated with the risk of plague. This phenomenon is valuable for Himalayan marmot and plague prevention. More studies are needed to understand the impact of climate change on Himalayan marmot and plague.
文摘Inspired by recent environmental historical studies on animal extinctions and human-animal relations,this paper shifts scholarly attention from the plague-centered narrative of the great Pneumonic Plague Epidemics(1910—11)to the fate of the plague host animals,Tarbagan marmots(Marmota sibirica>,and examines their ncar-extinction in Northwest Manchuria(Hulunbuir)from the 1900s to 1930s.Focusing on changing images of Tarbagan marmots from“inexpensive,”“sacred,”and“beneficial”in the pre-modem period to“valuable,”“dangerous,”and“noxious”in the early twentieth century,it argues that three interrelated factors:the international fur trade,pneumonic plagues,and environment changes together resulted in the“retreat of the marmots.”It also]uses this case study to help us better understand larger historical changes that occurred by contextualizing them in terms of human-marmot relations in Manchuria,China and beyond.
基金supported by the National Geographic Society,the University of California Los Angeles(Faculty Senate and Division of Life Sciences)an RMBL research fellowship and the U.S.National Science Foundation(NSF IDBR-0754247 and DEB-1119660 and 1557130 to D.T.B.,as well as DBI 0242960,07211346 and 1226713 to RMBL).
文摘The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations often sound“noisy”because vocal production systems are over-blown when animals are highly aroused.While much is known about the conditions under which animals produce vocalizations containing NLP and how species respond to them,there is little research about the heritability of such behavioral traits.Using the quantitative genetic animal model,we estimated the genetic basis of“noise”in alarm calls produced by females and found significant heritability in call entropy-our measure of the noisiness.About 9%of the variance in noisiness can be accounted for by genetic differences.Taken together,these findings suggest that the degree to which marmots produce noisy calls is modestly heritable and can be thus subject to further evolution via natural selection.
基金supported by the University of Ottawa and a NSERC Discovery grant(DGECR-2019-00289,RGPIN-2019-05000)the National Geographic Society,the University of California Los Angeles(Faculty Senate and Division of Life Sciences),an RMBL research fellowship,and the U.S.National Science Foundation(NSF IDBR-0754247 and DEB-1119660 and 1557130 to D.T.B.,as well as DBI 0242960,07211346,1226713,and 1755522 to RMBL).
文摘Climate change and its resulting effects on seasonality are known to alter a variety of animal behaviors including those related to foraging,phenology,and migration.Although many studies focus on the impacts of phenological changes on physiology or ftness enhancing behaviors,fewer have investigated the relationship between variation in weather and phenology on risk assessment.Fleeing from predators is an economic decision that incurs costs and benefts.As environmental conditions change,animals may face additional stressors that affect their decision to fee and infuence their ability to effectively assess risk.Flight initiation distance(FID)—the distance at which animals move away from threats—is often used to study risk assessment.FID varies due to both internal and external biotic and physical factors as well as anthropogenic activities.We asked whether variation in weather and phenology is associated with risk-taking in a population of yellow-bellied marmots(Marmota faviventer).As the air temperature increased marmots tolerated closer approaches,suggesting that they either perceived less risk or that their response to a threat was thermally compromised.The effect of temperature was relatively small and was largely dependent upon having a larger range in the full data set that permitted us to detect it.We found no effects of either the date that snow disappeared or July precipitation on marmot FID.As global temperatures continue to rise,rainfall varies more and drought becomes more common,understanding climate-related changes in how animals assess risk should be used to inform population viability models.
