Canine distemper virus(CDV)has recently been identified in populations of wild tigers in Russia and India.Tiger populations are generally too small to maintain CDV for long periods,but are at risk of infections arisin...Canine distemper virus(CDV)has recently been identified in populations of wild tigers in Russia and India.Tiger populations are generally too small to maintain CDV for long periods,but are at risk of infections arising from more abundant susceptible hosts that constitute a reservoir of infection.Because CDV is an additive mortality factor,it could represent a significant threat to small,isolated tiger populations.In Russia,CDV was associated with the deaths of tigers in 2004 and 2010,and was coincident with a localized decline of tigers in Sikhote-Alin Biosphere Zapovednik(from 25 tigers in 2008 to 9 in 2012).Habitat continuity with surrounding areas likely played an important role in promoting an ongoing recovery.We recommend steps be taken to assess the presence and the impact of CDV in all tiger range states,but should not detract focus away from the primary threats to tigers,which include habitat loss and fragmentation,poaching and retaliatory killing.Research priorities include:(i)recognition and diagnosis of clinical cases of CDV in tigers when they occur;and(ii)collection of baseline data on the health of wild tigers.CDV infection of individual tigers need not imply a conservation threat,and modeling should complement disease surveillance and targeted research to assess the potential impact to tiger populations across the range of ecosystems,population densities and climate extremes occupied by tigers.Describing the role of domestic and wild carnivores as contributors to a local CDV reservoir is an important precursor to considering control measures.展开更多
Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-speci...Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-specific mortality of tigers.We used cumulative incidence functions(CIFs)to quantify cause-specific mortality rates of tigers,expanding and refining earlier studies to assess the potential impact of a newly emerging disease.To quantify changes in tiger mortality over time,we re-examined data first collected by Goodrich et al.(2008;study period 1:1992–2004)as well as new telemetry data collected since January 2005(study period 2:2005–2012)using a total of 57 tigers(27 males and 30 females)monitored for an average of 747 days(range 26–4718 days).Across the entire study period(1992 to 2012)we found an estimated average annual survival rate of 0.75 for all tigers combined.Poaching was the primary cause of mortality during both study periods,followed by suspected poaching,distemper and natural/unknown causes.Since 2005,poaching mortality has remained relatively constant and,if combined with suspected poaching,may account for a loss of 17–19%of the population each year.Canine distemper virus(CDV)may be an additive form of mortality to the population,currently accounting for an additional 5%.Despite this relatively new source of mortality,poaching remains the main threat to Amur tiger survival and,therefore,population growth.展开更多
基金We would like to thank the Morris Animal Foundation,Zoo Boise,and the Biotechnology and Biological Sciences Research Council for their generous support of the project.In addition,none of this work would have been possible without the continued partnership of the Sikhote-Alin Biosphere Zapovednik(Director D.Yu.Gorskhov),Lazovskii Zapovednik(Director A.A.Laptev)and the Russian Ministry of Natural Resources.Thanks also to V.Keahey(In-Sync Exotics)for insights into the epidemiology of CDV.
文摘Canine distemper virus(CDV)has recently been identified in populations of wild tigers in Russia and India.Tiger populations are generally too small to maintain CDV for long periods,but are at risk of infections arising from more abundant susceptible hosts that constitute a reservoir of infection.Because CDV is an additive mortality factor,it could represent a significant threat to small,isolated tiger populations.In Russia,CDV was associated with the deaths of tigers in 2004 and 2010,and was coincident with a localized decline of tigers in Sikhote-Alin Biosphere Zapovednik(from 25 tigers in 2008 to 9 in 2012).Habitat continuity with surrounding areas likely played an important role in promoting an ongoing recovery.We recommend steps be taken to assess the presence and the impact of CDV in all tiger range states,but should not detract focus away from the primary threats to tigers,which include habitat loss and fragmentation,poaching and retaliatory killing.Research priorities include:(i)recognition and diagnosis of clinical cases of CDV in tigers when they occur;and(ii)collection of baseline data on the health of wild tigers.CDV infection of individual tigers need not imply a conservation threat,and modeling should complement disease surveillance and targeted research to assess the potential impact to tiger populations across the range of ecosystems,population densities and climate extremes occupied by tigers.Describing the role of domestic and wild carnivores as contributors to a local CDV reservoir is an important precursor to considering control measures.
文摘Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-specific mortality of tigers.We used cumulative incidence functions(CIFs)to quantify cause-specific mortality rates of tigers,expanding and refining earlier studies to assess the potential impact of a newly emerging disease.To quantify changes in tiger mortality over time,we re-examined data first collected by Goodrich et al.(2008;study period 1:1992–2004)as well as new telemetry data collected since January 2005(study period 2:2005–2012)using a total of 57 tigers(27 males and 30 females)monitored for an average of 747 days(range 26–4718 days).Across the entire study period(1992 to 2012)we found an estimated average annual survival rate of 0.75 for all tigers combined.Poaching was the primary cause of mortality during both study periods,followed by suspected poaching,distemper and natural/unknown causes.Since 2005,poaching mortality has remained relatively constant and,if combined with suspected poaching,may account for a loss of 17–19%of the population each year.Canine distemper virus(CDV)may be an additive form of mortality to the population,currently accounting for an additional 5%.Despite this relatively new source of mortality,poaching remains the main threat to Amur tiger survival and,therefore,population growth.
