Anindya Naskar

Owls (order Strigiformes) represent a highly specialized lineage of nocturnal raptors, within which the genus Strix (family Strigidae) comprises several widely distributed species despite the limited availability of comprehensive mitogenomic data. In this study, the complete mitogenome of the Mottled Wood-owl, Strix ocellata (Lesson, 1839), was characterized to investigate its genomic organization, structural features, and patterns of gene rearrangement. Furthermore, the phylogenetic position of S. ocellata was evaluated within the broader lineage of Strigiformes using concatenated mitochondrial protein-coding genes (PCGs), and among congeners using partial COI and Cytb genes. The circular mitogenome of S. ocellata was 19,135 bp in length and comprised the typical vertebrate mitochondrial complement of 13 PCGs, 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and two non-coding control regions (CRs). The selective pressure analyses revealed strong purifying selection acting across all PCGs, whereas codon usage analysis demonstrated biased synonymous codon preferences, with arginine, leucine, and serine representing the most abundant amino acids. The CR retained the three characteristic conserved domains, while variation in tandem repeat motifs suggested evolutionary divergence among the examined taxa. The phylogenetic inference based on complete mitogenome datasets strongly supported the monophyly of the genus Strix . Notably, S. ocellata occupied a putatively basal position relative to other Strix species based on both complete mitogenomes and partial mitochondrial markers. The comparative examination of mitochondrial gene arrangements revealed a largely conserved genomic architecture across Strigiformes, with observed transposition and duplication events involving ND6, Cytb, several tRNA genes, and the CRs. Collectively, this study provides the first mitogenomic characterization of S. ocellata as well as evolutionary relationships within Strix and the broader Strigiformes lineage. Nevertheless, these findings underscore the need for additional complete mitogenome sequences and whole-genome datasets from broader taxonomic and geographic sampling. Such expanded genomic resources will improve phylogenetic resolution and facilitate a more comprehensive understanding of the evolutionary history and diversification of this owl lineage.

This study was aimed at documenting the winter bird diversity in the pine and secondary forest dominated landscape of Walong Reserve Forest in Arunachal Pradesh bordering China and Myanmar. Walong is one of the least explored regions in India but rich in bird diversity, as it is part of Ditchu Reserve Forest, designated as one of the Important Bird and Biodiversity Areas. This is the first comprehensive study that highlights important species found in this region, as no published bird list is available for the region. We conducted random surveys in 2021, 2022 and 2023, especially during winter months and documented 117 species belonging to 77 genera, 42 families and 11 orders during our surveys in the Walong area of Arunachal Pradesh. Family Muscicapidae was the dominant group with 9 genera and 21 species with an RDi value of 17.9%, followed by Leiothrichidae (5 genera and 7 species) and Phylloscopidae (1 genus comprising 7 species of warblers) with an RDi value of 6%. Sighting of the Critically Endangered White-bellied Heron Ardea insignis was the highlight of the survey, as Walong is the new extended range for the species, further north of its earlier known distribution in India. We also recorded a further nesting record of the Lord Derby’s Parakeet Psittacula derbiana, as the species has extended its range to India from the neighbouring China.