N. Soni and P.V. Thakare
Abstract
Identification of wildlife species from non-invasive samples remains a major challenge in ecological and conservation studies, as field-based identification of scats is often unreliable, particularly in landscapes supporting multiple sympatric carnivores and omnivores. The sloth bear (Melursus ursinus), a Vulnerable species with a highly diverse and seasonally variable diet, produces scats that can differ considerably in appearance and composition, complicating morphological identification. Molecular approaches provide a robust alternative for species confirmation while simultaneously generating genetic information useful for conservation planning. A mitochondrial gene, cytochrome c oxidase subunit I (COI), has been widely used as a marker for species identification and assessment of genetic variation. In the present study, 98 non invasive scat samples collected from Melghat Tiger Reserve, Maharashtra, India, were used to genetically confirm species identity and assess mitochondrial variation in sloth bears. Species identification was initially performed using sloth bear-specific mitochondrial primers achieving a success rate of 52%, followed by COI amplification and sequencing. COI sequencing of 20 representative samples from spatially distinct locations were selected to validate species identity and examine mitochondrial variation. All 20 sequenced samples were confirmed as sloth bear, demonstrating the effectiveness of both species-specific and COI based approaches for non-invasive species identification. Sequence analysis of the 546 bp COI fragment identified 7 haplotypes defined by 9 polymorphic sites, of which 3 were parsimony-informative. Haplotype diversity and nucleotide diversity were estimated at 0.584 and 0.00241, respectively. One dominant haplotype accounted for 65% of the sampled individuals, while the remaining haplotypes occurred at lower frequencies. Phylogenetic analysis clustered all haplotypes within the sloth bear clade and clearly differentiated them from other bear species, further supporting the reliability of the COI marker for species identification. This study demonstrates the utility of non-invasive genetic approaches for accurate species identification and provides preliminary baseline information on mitochondrial variation in sloth bears from Melghat Tiger Reserve. Further studies incorporating larger sample sizes and additional mitochondrial and nuclear markers are required to obtain a comprehensive understanding of genetic diversity and population structure in the region.