This work serves as the definitive, comprehensive reference for the avian species inhabiting the Indian subcontinent and surrounding regions. Sálim Ali, a preeminent figure in Indian ornithology, compiled this extensive survey to provide a systematic classification and detailed biological account of the birds found in India, Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka. The text synthesizes decades of field observations and taxonomic research into a singular, accessible format for researchers and naturalists.

Experts and ornithologists regard this work as a foundational text for the study of South Asian avian life. Readers frequently note the immense density of the technical data, which remains a standard reference for professional and amateur researchers alike.