title: Niche modeling predictions of the potential distribution of Marmota himalayana, the host animal of plague in Yushu County of Qinghai.
abstract: BACKGROUND
  After the earthquake on 14, April 2010 at Yushu in China, a plague epidemic hosted by Himalayan marmot (Marmota himalayana) became a major public health concern during the reconstruction period. A rapid assessment of the distribution of Himalayan marmot in the area was urgent. The aims of this study were to analyze the relationship between environmental factors and the distribution of burrow systems of the marmot and to predict the distribution of marmots.
  
  
  METHODS
  Two types of marmot burrows (hibernation and temporary) in Yushu County were investigated from June to September in 2011. The location of every burrow was recorded with a global positioning system receiver. An ecological niche model was used to determine the relationship between the burrow occurrence data and environmental variables, such as land surface temperature (LST) in winter and summer, normalized difference vegetation index (NDVI) in winter and summer, elevation, and soil type. The predictive accuracies of the models were assessed by the area under the curve of the receiving operator curve.
  
  
  RESULTS
  The models for hibernation and temporary burrows both performed well. The contribution orders of the variables were LST in winter and soil type, NDVI in winter and elevation for the hibernation burrow model, and LST in summer, NDVI in summer, soil type and elevation in the temporary burrow model. There were non-linear relationships between the probability of burrow presence and LST, NDVI and elevation. LST of 14 and 23 °C, NDVI of 0.22 and 0.60, and 4100 m were inflection points. A substantially higher probability of burrow presence was observed in swamp soil and dark felty soil than in other soil types. The potential area for hibernation burrows was 5696 km(2) (37.7% of Yushu County), and the area for temporary burrows was 7711 km(2) (51.0% of Yushu County).
  
  
  CONCLUSIONS
  The results suggested that marmots preferred warm areas with relatively low altitudes and good vegetation conditions in Yushu County. Based on these results, the present research is useful in understanding the niche selection and distribution pattern of marmots in this region.
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. luliang@icdc.cn.|Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. luliang@icdc.cn.
authors.forename: Liang
authors.initials: L
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, 100101, China. renzp@lreis.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. renzp@lreis.ac.cn.|Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. renzp@lreis.ac.cn.
authors.forename: Zhoupeng
authors.initials: Z
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. yueyujuan@icdc.cn.
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Yue
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. qhyxt@qq.com.
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. lushan@icdc.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. liguichang@icdc.cn.
authors.forename: Guichang
authors.initials: G
authors.lastname: Li
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. lihailongqhxn@163.com.
authors.forename: Hailong
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. weijianchun@icdc.cn.
authors.forename: Jianchun
authors.initials: J
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. liujingli@icdc.cn.
authors.forename: Jingli
authors.initials: J
authors.lastname: Liu
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. longlong1218@sohu.com.
authors.forename: You
authors.initials: Y
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. hairong@icdc.cn.
authors.forename: Rong
authors.initials: R
authors.lastname: Hai
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. yangyonghai07@163.com.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. www08www@163.com.
authors.forename: Rongjie
authors.initials: R
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. kanbiao@icdc.cn.
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. whqhxn@126.com.
authors.forename: Hu
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, 100101, China. wangjf@lreis.ac.cn.|Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. wangjf@lreis.ac.cn.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Qinghai Institute for Endemic Disease Prevention and Control, Qinghai, 811602, China. wangzuyun2006@163.com.
authors.forename: Zuyun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. liuqiyong@icdc.cn.|Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. liuqiyong@icdc.cn.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China. xujianguo@icdc.cn.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D055866:Earthquakes; D017753:Ecosystem; D058872:Epidemics; D040362:Geographic Information Systems; D008392:Marmota / Q000382:microbiology; D008954:Models, Biological; D010930:Plague / Q000453:epidemiology*; D011336:Probability; D012621:Seasons; D012987:Soil; D013696:Temperature
chemical_list: D012987:Soil