This text investigates the ecological requirements, behavioral patterns, and conservation status of the world's thirteen otter species. Hans Kruuk, a recognized authority in the field of carnivore ecology, synthesizes decades of field research and observational data to construct a comprehensive framework for understanding how these semi-aquatic mammals interact with their environments. The book argues that effective conservation management must be rooted in a deep understanding of species-specific social structures and habitat dependencies.

Experts and researchers frequently cite this work as a foundational text for understanding the complexities of otter biology and the challenges of their preservation. Readers often note the academic rigor and the clear, evidence-based approach Kruuk employs throughout the volume.