Introduction: Oak Bottom Wildlife Refuge is a flourishing ecosystem located in northern California, renowned for its diverse range of avian species. Among the notable inhabitants of this refuge is the common merganser (Mergus merganser), a captivating waterfowl species that plays a vital role in the ecosystem. This essay aims to explore the habitat, behavior, and conservation of the common merganser in Oak Bottom Wildlife Refuge, shedding light on the importance of preserving this species and its environment. Habitat: The common merganser is predominantly found in…