中国及其他分布区域野生虎的系统地理学和遗传起源研究进展

世界野生虎(Pantheratigris)传统上被划分为8个亚种,其中3个亚种已于20世纪灭绝,而剩余种群的生存仍然受到偷猎、栖息地丧失和片断化的威胁。作为唯一栖息着4个现存虎亚种的国家,中国在世界虎的保护事业中负有重要责任,然而其野生和圈养虎的分类地位却仍然不确定。最近一项研究(Luoetal,2004)从所有现存野生虎分布地区(包括中国)采集了134份“基准样品”(即原产野外或有确定地域起源的个体生物样品),对虎的系统地理学、种群结构以及遗传起源进行了全面分析。所用的分子标记包括四千碱基对的线粒体DNA、30个核基因组微卫星位点,以及MHC-DRB基因。研究结果表明,虽然虎的整体遗传多态性较低,但是种群分化程度很高,它们被划分为6个,而不是5个现存亚种(1)西伯利亚虎(P.t.altaica);(2)苏门答腊虎(P.t.sumatrae);(3)孟加拉虎(P.t.tigris);(4)华南虎(P.t.amoyensis);(5)印支虎(P.t.corbetti);(6)新定义的亚种马来虎,暂命名为P.t.Jacksoni。由于所研究样本量有限,目前暂定的华南虎亚种还需进一步确定。现有华南虎圈养种群包括遗传关系相距较远的两支一支与印支虎(P.t.corbetti)无异;而另一支则与其他种群均相距甚远,可能代表了真正的华南虎(P.t.amoyensis)。利用分子生物学方法对中国动物园中圈养虎的遗传起源调查亟待进行,以确认该圈养种群整体的遗传独特性或者非独特性。换言之,这将是确认华南虎是否仍然存在的关键。

A comparison of food habits and prey preference of Amur tiger(Panthera tigris altaica)at three sites in the Russian Far East

Prey availability is one of the principal drivers of tiger distribution and abundance.Therefore,formulating effective conservation strategies requires a clear understanding of tiger diet.We used scat analysis in combination with data on the abundance of several prey species to estimate Amur tiger diet and preference at 3 sites in the Russian Far East.We also examined the effect of pseudoreplication on estimates of tiger diet.We collected 770 scats across the 3 sites.Similar to previous studies,we found that tigers primarily preyed on medium to large ungulates,with wild boar,roe,sika and red deer collectively comprising 86.7%of total biomass consumed on average.According to Jacobs’index,tigers preferred wild boar,and avoided sika deer.Variation in preference indices derived from these scat analyses compared to indices derived from kill data appear to be due to adjustments in biomass intake when sex–age of a killed individual is known:a component missing from scat data.Pseudoreplication(multiple samples collected from a single kill site)also skewed results derived from scat analyses.Scat analysis still appears useful in providing insight into the diets of carnivores when the full spectrum of prey species needs to be identified,or when sample sizes from kill data are not sufficient.When sample sizes of kill data are large(as is now possible with GPS-collared animals),kill data adjusted by sex–age categories probably provides the most accurate estimates of prey biomass composition.Our results provide further confirmation of the centrality of medium ungulates,in particular wild boar,to Amur tiger diet,and suggest that the protection of this group of species is critical to Amur tiger conservation.

Population dynamics of Amur tigers(Panthera tigris altaica)in Sikhote-Alin Biosphere Zapovednik:1966–2012

In 2010,the world’s tiger(Panthera tigris)range countries agreed to the goal of doubling tiger numbers over 12 years,but whether such an increase is biologically feasible has not been assessed.Long-term monitoring of tigers in Sikhote-Alin Biosphere Zapovednik(SABZ),Russia provided an opportunity to determine growth rates of a recovering population.A 41-year growth phase was followed by a rapid decline in tiger numbers.Annual growth rates during the growth phase averaged 4.6%,beginning near 10%in the earliest years but quickly dropping below 5%.Sex ratio(females per male)mirrored growth rates,declining as population size increased.The rapid decline from 2009 to 2012 appeared to be tied to multiple factors,including poaching,severe winters and disease.Reproductive indicators of this population are similar to those of Bengal tiger populations,suggesting that growth rates may be similar.These results suggest that,first,tiger populations likely in general grow slowly:3–5%yearly increases are realistic and larger growth rates are likely only when populations are highly depressed,mortality rates are low and prey populations are high relative to numbers of adult females.Second,while more research is needed,it should not be assumed that tiger populations with high prey densities will necessarily grow more quickly than populations with low prey densities.Third,while growth is slow,decline can be rapid.Fourth,because declines can happen so quickly,there is a constant need to monitor populations and be ready to respond with appropriate and timely conservation interventions if tiger populations are to remain secure.Finally,an average annual growth rate across all tiger populations of 6%,required to reach the Global Tiger Initiative’s goal of doubling tiger numbers in 12 years,is a noble but unlikely scenario.

Canine distemper virus as a threat to wild tigers in Russia and across their range

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.

Mortality of Amur tigers:The more things change,the more they stay the same

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.

Social structure and space use of Amur tigers(Panthera tigris altaica)in Southern Russian Far East based on GPS telemetry data

To better understand the spatial structure of Amur tigers(Panthera tigris altaica)at the southern edge of their range we fitted 14 tigers(6♀♀and 8♂♂)with 15 GPS-Argos collars between 2008 and 2011 in 2 study sites:the Ussuriskii Reserve of southern Sikhote-Alin and the Land of the Leopard National Park in southwest Primorye,Russian Far East.Fixed kernel estimates of male home ranges were larger than those of female home ranges(P<0.05[mean 95%fixed kernel♀=401±205 km2;mean 95%fixed kernel♂=778±267 km2]).The home range size of females varied greatly,but on average was similar to estimates derived from earlier work further north.Low overlap of adjacent home ranges suggested that females retained exclusive territories.Real core areas of females overlapped only slightly,and remained stable over multiple years.The home ranges of adult males were smaller than those of males to the north,and in contrast to previous studies,high overlap among males indicated the absence of territoriality.Nonetheless,real core areas of males did not overlap,suggesting some spatial separation.In comparison to other tiger populations and other areas of the Russian Far East,the sex ratio in our 2 study areas was highly skewed towards males.We believe this skewed sex ratio resulted in the dissolution of territoriality of males due to an inability to defend individual females,with males resorting to scramble competition for mates.Continued monitoring of these sites to determine whether shifts in the sex ratio might result in a return to male territoriality would provide confirmation of our tentative hypothesis.

Indicators of success for smart law enforcement in protected areas:A case study for Russian Amur tiger(Panthera tigris altaica)reserves

Although considerable conservation resources have been committed to develop and use law enforcement monitoring and management tools such as SMART,measures of success are ill-defined and,to date,few reports detail results post-implementation.Here,we present 4 case studies from protected areas with Amur tigers(Panthera tigris altaica)in Russia,in which indicators of success were defined and evaluated at each.The ultimate goal was an increase in tiger numbers to 1 individual/100 km^(2)at each site.We predicted that improvements in law enforcement effectiveness would be followed by increases in prey numbers and,subsequently,tiger numbers.We used short-term and long-term indicators of success,including:(i)patrol team effort and effectiveness;(ii)catch per unit effort indicators(to measure reductions in threats);and(iii)changes in target species numbers.In addition to implementing a monitoring system,we focused on improving law enforcement management using an adaptive management process.Over 4 years,we noted clear increases in patrol effort and a partial reduction in threats.Although we did not detect clear trends in ungulate numbers,tiger populations remained stable or increased,suggesting that poaching of tigers may be more limiting than prey depletion.Increased effectiveness is needed before a clear reduction in threats can be noted,and more time is needed before detecting responses in target populations.Nonetheless,delineation of concrete goals and indicators of success provide a means of evaluating progress and weaknesses.Such monitoring should be a central component of law enforcement strategies for protected areas.

Review of research methodologies for tigers:Telemetry

Over the past half century,wildlife research has relied on technological advances to gain additional insight into the secretive lives of animals.This revolution started in the 1960s with the development of radio telemetry and continues today with the use of Global Positioning System(GPS)-based research techniques.In the present paper we review the history of radio telemetry from its origins with grizzly bears in Yellowstone to its early applications in tiger research and conservation in Asia.We address the different types of data that are available using radio telemetry as opposed to using other research techniques,such as behavioral observations,camera trapping,DNA analysis and scat analysis.In the late 1990s,the rapid development of GPS collar technology revolutionized wildlife research.This new technology has enabled researchers to dramatically improve their ability to gather data on animal movements and ecology.Despite the ecological and conservation benefits of radio telemetry,there have been few telemetry studies of tigers in the wild,and most have been on the Bengal or Amur subspecies.We close with an assessment of the current tiger conservation efforts using GPS technology and discuss how this new information can help to preserve tigers for future generations.

The Amur tiger in Northeast Asia:Conservation and ecology of an endangered subspecies

When I first traveled to Russia to begin a radiotelemetry project on Amur tigers,I was operating on the false assumption that we would be“the first”to study and begin to understand the ecology of this northernmost subspecies of tigers.My ignorance was,as it turned out,primarily a language barrier,as nearly all work that had been conducted on this subspecies existed in either Russian or Chinese languages.

Identifying ecological corridors for Amur tigers(Panthera tigris altaica)and Amur leopards(Panthera pardus orientalis)

The rapid explosion of human populations and the associated development of human-dominated landscapes have drastically reduced and fragmented habitat for tigers(Panthera tigris)and leopards(Panthera pardus)across Asia,resulting in multiple small populations.However,Amur tiger(Panthera tigris altaica)habitat in Russia has remained largely interconnected,except for a break between tigers in southwest Primorye and the southern Sikhote-Alin Mountains.This habitat patch in southwest Primorye also retains the last population of Amur leopards(Panthera pardus orientalis).Genetic differentiation of tigers in southwest Primorye and the Sikhote-Alin Mountains along with survey data suggest that habitat fragmentation is limiting movement of tigers and leopards across the Razdolnaya River basin.We looked at historical and recent survey data on tigers and leopards and mapped existing cover types to examine land-use patterns of both large felids and humans in the development strip along the Razdolnaya River.We then used least-cost distance analyses to identify the most effective potential corridor to retain connectivity for large felids between Land of the Leopard National Park and Ussuriskii Zapovednik(Reserve).We identified a single potential corridor that still exists with a total distance of 62.5 km from Land of the Leopard National Park to Ussuriskii Zapovednik,mostly(93%)through forested habitat.We recommend formal recognition of a Razdolnaya ecological corridor and provide specific recommendations for each of 3 proposed management sections.