Cave-dwelling birds are species that inhabit caves or similar dark environments. These birds have adapted to life in low-light conditions, often developing unique physical traits such as reduced eyesight and specialized feathers for navigating tight spaces. They typically rely on echolocation or heightened senses of hearing to find food and avoid obstacles. One well-known example of a cave-dwelling bird is the swiftlet, which builds its nests in caves using saliva. These nests are highly valued in some cultures, particularly in Southeast Asia, where they are used to make bird's nest soup. Cave-dwelling birds play important roles in their ecosystems, contributing to nutrient cycling and pest control.