Validation of non-invasive genetic identification of two elusive, sympatric, sister-species - tiger (Panthera tigris) and leopard (Panthera pardus).

Population and conservation genetic studies of endangered species increasingly rely on non-invasively collected samples like hair and faeces. The extant genotyping errors in such samples can be further aggravated in studies on sympatric, closely related species like tiger (Panthera tigris) and leopard (Panthera pardus), where mistakes in species identification can lead to erroneous population estimation, structure and genetic diversity. In this study we assessed possible errors in identification of tiger/leopard faecal samples with published species identification markers. We further analysed a panel of cross-species, polymorphic microsatellite loci for individual identification of both tigers and leopards with an aim to understand the level of allelic overlaps between the two species and to identify a subset of loci useful in eliminating errors in species identification. Two out of four species-specific primers show cross-species amplification. The suite of microsatellite markers used in this study is informative enough to identify individuals and establish genetic diversity in both species. However, 11 out of 13 microsatellites loci exhibit overlapping alleles in tigers and leopards. One locus (Fca96) does not amplify in leopard, whereas only one locus (F124) shows different allelic ranges in the two species. Prior to taking up non-invasive genetic studies on one/multiple sympatric species, it is important to accurately identify the origin of samples. Further, we recommend correct identification of private alleles in each species which will help in eliminating errors in species identification. [ABSTRACT FROM AUTHOR]