An expeditious method for ascertaining species between black bear (Selenarctos thibetanus G. cuiver) and brown bear (Ursus arctos Linnaeus) was developed using tooth measurements from previously identified specimens. ...An expeditious method for ascertaining species between black bear (Selenarctos thibetanus G. cuiver) and brown bear (Ursus arctos Linnaeus) was developed using tooth measurements from previously identified specimens. The measurement and analysis on 18 tooth measurement indexes (i.e. T1. Length of Pm1-Pm4, T2. L. of M1-M3, T3. M1L., T4. M1 width, T5. M2L., T6. M2W., T7.M3L., T8. M3W., T9. L. of C1 alveolus, T10. W. of C1 alveolus, T11. L. of C1-M2, T12. L. of Pm4 M2,T13.M1L., T14. M1W., T15. M2L., T16. M2W., T17.L. of C1 alveolus, T18. W. of C1 alveolus) of 59 skulls (black bears 25, brown bears 34) indicates that there are significant or the most significant difference between two species in every indexes, however T1, T9, T10, T17 and T18 are not suitable for species discriminator because of their high percent of overlap. The efficient species discriminators and standards (mm) are as follows T2(63.0), T3(22.0), T4(10.2), T5(23.8), T6(13.6), T7(18.0), T8(13.5), T11(110.0),T12(66.0), T13(20. 1), T14(15.8), T15(33.0) and T16(17.3). Those who are less than or equal to standard are classified to black bear, the others are brown bear. The method is very convenient and useful with high reliability. Their lowest accuracy percent are 95.0%, most of them over 97%. Different indexes will be chosen refer to the degree of specimen destroyed.展开更多
Climate change is one of the threats in the recent century,affecting biodiversity directly and indirectly.Modeling the patterns of species distribution is one of useful tools for predicting the impacts of climate chan...Climate change is one of the threats in the recent century,affecting biodiversity directly and indirectly.Modeling the patterns of species distribution is one of useful tools for predicting the impacts of climate change on endangered species.Brown bear(Ursus arctos)plays an important role as a focal species in mountainous ecosystems.This study was aims to investigate the effects of future climate changes on the distribution of this species using an ensemble modeling method in R-software.For this purpose five algorithms including MAXENT,RF,MARS,GAM,GLM and BRT were used to predict the distribution of the species in the present climatic conditions as well as in the 2050s and 2070s.The results showed that temperature and precipitation were two main factors in the distribution of brown bears in Iran.Investigating the distribution of the brown bear in the future showed that suitability of its habitat will decrease in the western and central parts and increase in the northern parts.So a shift toward higher altitude will be expected for brown bear in the future.Therefore,in this condition it is imperative to upgrade the extent of protected areas for better conservation of brown bear.展开更多
Populations of the European brown bear (Ursus arctos L.) differ substantially in size, degree of geographic isolation and level of genetic diversity. Present patterns result from phylogeographic processes and profound...Populations of the European brown bear (Ursus arctos L.) differ substantially in size, degree of geographic isolation and level of genetic diversity. Present patterns result from phylogeographic processes and profound human intervention. We assessed the genetic variability of a subpopulation of brown bears near the periphery of their range in the Western Carpathian Mountains and compared their genetic properties with those of bears in the core of the same population and elsewhere. Samples were collected non-invasively in 2007-2008 and2010 in Strázovské Vrchy Protected Landscape Area (PLA) in Slovakia (included in the NATURA 2000 networking programme). Seven polymorphic microsatellite loci (UaMU26, UaMU64, G10B, G1D, G10L, UaMU50 and UaMU51) were amplified using a nested PCR in order to assess the following parameters: variability, allelic combinations, heterozygosity, number of alleles and inbreeding coefficient. Sufficient brown bear DNA for analysis was obtained from 57 out of 140 samples (41%), among which 45 different genotypes were identified. Loci had a mean of 2.71 ± 0.76 alleles. Average observed heterozygosity was 0.59. The inbreeding coefficient was negative for all but one of the analysed loci (2007-2008). In the year 2010 was negative three of seven loci. These results imply that gene flow with other parts of the population has been maintained in the reduced level and the isolation level of bears in the study area was not so low. Nevertheless, the genetic variability of bears in Strázovské Vrchy PLA was lower than that reported from other localities in the Carpathian Mountains. The results are discussed in the context of behavioural ecology and conservation genetics.展开更多
文摘An expeditious method for ascertaining species between black bear (Selenarctos thibetanus G. cuiver) and brown bear (Ursus arctos Linnaeus) was developed using tooth measurements from previously identified specimens. The measurement and analysis on 18 tooth measurement indexes (i.e. T1. Length of Pm1-Pm4, T2. L. of M1-M3, T3. M1L., T4. M1 width, T5. M2L., T6. M2W., T7.M3L., T8. M3W., T9. L. of C1 alveolus, T10. W. of C1 alveolus, T11. L. of C1-M2, T12. L. of Pm4 M2,T13.M1L., T14. M1W., T15. M2L., T16. M2W., T17.L. of C1 alveolus, T18. W. of C1 alveolus) of 59 skulls (black bears 25, brown bears 34) indicates that there are significant or the most significant difference between two species in every indexes, however T1, T9, T10, T17 and T18 are not suitable for species discriminator because of their high percent of overlap. The efficient species discriminators and standards (mm) are as follows T2(63.0), T3(22.0), T4(10.2), T5(23.8), T6(13.6), T7(18.0), T8(13.5), T11(110.0),T12(66.0), T13(20. 1), T14(15.8), T15(33.0) and T16(17.3). Those who are less than or equal to standard are classified to black bear, the others are brown bear. The method is very convenient and useful with high reliability. Their lowest accuracy percent are 95.0%, most of them over 97%. Different indexes will be chosen refer to the degree of specimen destroyed.
文摘Climate change is one of the threats in the recent century,affecting biodiversity directly and indirectly.Modeling the patterns of species distribution is one of useful tools for predicting the impacts of climate change on endangered species.Brown bear(Ursus arctos)plays an important role as a focal species in mountainous ecosystems.This study was aims to investigate the effects of future climate changes on the distribution of this species using an ensemble modeling method in R-software.For this purpose five algorithms including MAXENT,RF,MARS,GAM,GLM and BRT were used to predict the distribution of the species in the present climatic conditions as well as in the 2050s and 2070s.The results showed that temperature and precipitation were two main factors in the distribution of brown bears in Iran.Investigating the distribution of the brown bear in the future showed that suitability of its habitat will decrease in the western and central parts and increase in the northern parts.So a shift toward higher altitude will be expected for brown bear in the future.Therefore,in this condition it is imperative to upgrade the extent of protected areas for better conservation of brown bear.
基金supported by Structural Funds of EU Project of the Agency of the Ministry of Education,Science,Research and Sport of the Slovak Republic,Bratislava,ITMS No.26110230078
文摘Populations of the European brown bear (Ursus arctos L.) differ substantially in size, degree of geographic isolation and level of genetic diversity. Present patterns result from phylogeographic processes and profound human intervention. We assessed the genetic variability of a subpopulation of brown bears near the periphery of their range in the Western Carpathian Mountains and compared their genetic properties with those of bears in the core of the same population and elsewhere. Samples were collected non-invasively in 2007-2008 and2010 in Strázovské Vrchy Protected Landscape Area (PLA) in Slovakia (included in the NATURA 2000 networking programme). Seven polymorphic microsatellite loci (UaMU26, UaMU64, G10B, G1D, G10L, UaMU50 and UaMU51) were amplified using a nested PCR in order to assess the following parameters: variability, allelic combinations, heterozygosity, number of alleles and inbreeding coefficient. Sufficient brown bear DNA for analysis was obtained from 57 out of 140 samples (41%), among which 45 different genotypes were identified. Loci had a mean of 2.71 ± 0.76 alleles. Average observed heterozygosity was 0.59. The inbreeding coefficient was negative for all but one of the analysed loci (2007-2008). In the year 2010 was negative three of seven loci. These results imply that gene flow with other parts of the population has been maintained in the reduced level and the isolation level of bears in the study area was not so low. Nevertheless, the genetic variability of bears in Strázovské Vrchy PLA was lower than that reported from other localities in the Carpathian Mountains. The results are discussed in the context of behavioural ecology and conservation genetics.
