Male tigers(Panthera tigris altaica) in captivity copulate alternatively with an estrous female,suggesting a potential for heteropaternity as an effective reproductive strategy to maximize genetic diversity of offspri...Male tigers(Panthera tigris altaica) in captivity copulate alternatively with an estrous female,suggesting a potential for heteropaternity as an effective reproductive strategy to maximize genetic diversity of offspring.We analyzed microsatellites to test and compare the genetic output of multiple male mating(simultaneous polyandry) and single male mating(monogamy) with a female in a captive population.Simultaneous polyandry resulted in heteropaternity in 66.7% observed litters.No significant differences between parental populations and between offspring populations were detected in the number of alleles(A),expected heterozygosity(H e),number of effective alleles(N e) per locus and standard individual heterozygosity(SH)(P>0.05 for all 4 indexes).Comparisons showed no significant reduction of A,H o,H e and SH from parental population to offspring population for the two mating modes(P>0.05) except for SH in polyandrous families(P=0.029).However,such reduction was equivalent to single mating families when the influence of relatedness was eliminated using effective SH(E SH)(P>0.05).These results highlight an alternative strategy for managing captive populations of tiger and other wild felids in which animals are combined at one location allowing for copulation by multiple males to encourage heteropaternity in favor of maintained genetic diversity among offspring.展开更多
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...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.展开更多
A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild.We analyzed the breedin...A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild.We analyzed the breeding records of 68 female Amur tigers from 1995 to 2010 in the Hengdaohezi Felid Breeding Center of China and compared the reproductive parameters of this population to wild female Amur tigers.We found that the reproductive parameters of the captive population(the age of first parturition,length of gestation and litter survival rate)were not significantly different from those of wild Amur tigers.Differences in birth date and litter size between wild and captive populations may be caused by management protocols for the captive population or insufficient field data from the wild population.Reproductive parameters of females giving birth after losing a litter were similar to parameters of females that did not lose a litter,except for birth date.These results provide no indication of major problems in using captive females for a breeding program for release of cubs into the wild,but additional information is still needed to assess their suitability.展开更多
We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East.We identified 63 individuals after genotyping 256 feces,7 hair and 11 blo...We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East.We identified 63 individuals after genotyping 256 feces,7 hair and 11 blood samples collected within southern,central and northern Sikhote-Alin,as well as Southwest Primorye.Analysis of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote-Alin(some 500 km apart)than between animals from Ussuriskii State Nature Reserve and Southwest Primorye(less than 10 km apart at their nearest point),suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote-Alin Mountains.展开更多
So far,there has been no safe and convenient method to weigh the largefierce animals,like Amur tigers.To address this problem,we built models to predict the body weight of Amur tigers based on the fact that body weight...So far,there has been no safe and convenient method to weigh the largefierce animals,like Amur tigers.To address this problem,we built models to predict the body weight of Amur tigers based on the fact that body weight is proportional to body measurements or age.Using the method of body measurements,we extracted the body measurements from 4 different kinds of the lateral body image of tigers,that is,total lateral image,central lateral image,ellipsefitting image,and rectanglefitting image,and then we respectively used artificial neural network(ANN)and power regression model to analyze the predictive relationships between body weight and body measurements.Our results demonstrated that,among all ANN models,the model built with rectanglefitting image had the smallest mean square error.Comparatively,we screened power regression models which had the smallest Akakai information criteria(AIC).In addition,using the method of age,wefitted nonlinear regression models for the relationship between body weight and age and found that,for male tigers,logistic model had the smallest AIC.For female tigers,Gompertz model had the smallest AIC.Consequently,this study could be applied to estimate body weight of captive,or even wild,Amur tigers safely and conveniently,helping to monitor individual health and growth of the Amur tiger populations.展开更多
基金supported by the Program for New Century Excellent Talents in University (NCET-10-0280)Technological Development Project of Longyan City (2011LY017)
文摘Male tigers(Panthera tigris altaica) in captivity copulate alternatively with an estrous female,suggesting a potential for heteropaternity as an effective reproductive strategy to maximize genetic diversity of offspring.We analyzed microsatellites to test and compare the genetic output of multiple male mating(simultaneous polyandry) and single male mating(monogamy) with a female in a captive population.Simultaneous polyandry resulted in heteropaternity in 66.7% observed litters.No significant differences between parental populations and between offspring populations were detected in the number of alleles(A),expected heterozygosity(H e),number of effective alleles(N e) per locus and standard individual heterozygosity(SH)(P>0.05 for all 4 indexes).Comparisons showed no significant reduction of A,H o,H e and SH from parental population to offspring population for the two mating modes(P>0.05) except for SH in polyandrous families(P=0.029).However,such reduction was equivalent to single mating families when the influence of relatedness was eliminated using effective SH(E SH)(P>0.05).These results highlight an alternative strategy for managing captive populations of tiger and other wild felids in which animals are combined at one location allowing for copulation by multiple males to encourage heteropaternity in favor of maintained genetic diversity among offspring.
基金This study was part of the long-term“Program of Studying the Amur Tiger in the Russian Far East”within the framework of the Permanent Expedition of RAS for the Study of Animals Listed of the Red Data Book of the Russian Federation and Other Highly Important Animals of the Russian Fauna as well as within the Siberian Tiger Project of the Wildlife Conservation Society(WCS-Russia).The authors are grateful to the staff of the V.L.Komarov“Ussuriskii”State Nature Reserve,FEB RAS and the Land of the Leopard National Park for fruitful support in data collection,to Dr Andrey D.Poyarkov from the A.N.Severtsov Institute of Ecology and Evolution,RAS and to Mr Alexander L.Salman for discussion and technical support.This research was made within the framework of the Program for the Study of the Amur Tiger in the Russian Far East and was supported by the Russian Geography Society。
文摘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.
基金We are grateful for support provided through the Fundamental Research Funds for the Central Universities of China(2572014EA06 and 2572014AA14),the National Natural Science Foundation of China(NSFC31272336,31572285)and the"Study on Resource Survey Technology for Tiger and Amur Leopard Population"and"Standard of Tiger and Amur Leopard Population and Habitat Survey and Data Summarization"(State Forestry Administration).
文摘A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild.We analyzed the breeding records of 68 female Amur tigers from 1995 to 2010 in the Hengdaohezi Felid Breeding Center of China and compared the reproductive parameters of this population to wild female Amur tigers.We found that the reproductive parameters of the captive population(the age of first parturition,length of gestation and litter survival rate)were not significantly different from those of wild Amur tigers.Differences in birth date and litter size between wild and captive populations may be caused by management protocols for the captive population or insufficient field data from the wild population.Reproductive parameters of females giving birth after losing a litter were similar to parameters of females that did not lose a litter,except for birth date.These results provide no indication of major problems in using captive females for a breeding program for release of cubs into the wild,but additional information is still needed to assess their suitability.
文摘We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East.We identified 63 individuals after genotyping 256 feces,7 hair and 11 blood samples collected within southern,central and northern Sikhote-Alin,as well as Southwest Primorye.Analysis of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote-Alin(some 500 km apart)than between animals from Ussuriskii State Nature Reserve and Southwest Primorye(less than 10 km apart at their nearest point),suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote-Alin Mountains.
基金funded by the National Natural Science Foundation of China(NSFC31872241 and 31702031)the National Key Programme of Research and Development,the Ministry of Science and Technology(2016YFC0503200)+2 种基金the Fundamental Research Funds for the Central Universities(2572017PZ14 and 2572020BC05)the Biodiversity Survey,Monitoring and Assessment Project of Ministry of Ecology and EnvironEnvironment,China(2019HB2096001006)the Heilongjiang postdoctoral project fund(LBH-Z18003).
文摘So far,there has been no safe and convenient method to weigh the largefierce animals,like Amur tigers.To address this problem,we built models to predict the body weight of Amur tigers based on the fact that body weight is proportional to body measurements or age.Using the method of body measurements,we extracted the body measurements from 4 different kinds of the lateral body image of tigers,that is,total lateral image,central lateral image,ellipsefitting image,and rectanglefitting image,and then we respectively used artificial neural network(ANN)and power regression model to analyze the predictive relationships between body weight and body measurements.Our results demonstrated that,among all ANN models,the model built with rectanglefitting image had the smallest mean square error.Comparatively,we screened power regression models which had the smallest Akakai information criteria(AIC).In addition,using the method of age,wefitted nonlinear regression models for the relationship between body weight and age and found that,for male tigers,logistic model had the smallest AIC.For female tigers,Gompertz model had the smallest AIC.Consequently,this study could be applied to estimate body weight of captive,or even wild,Amur tigers safely and conveniently,helping to monitor individual health and growth of the Amur tiger populations.
