Where do true swifts build their nests?

True swifts exhibit diverse nesting habits, typically utilizing their sticky saliva to glue nest materials—such as twigs, buds, moss, or feathers—to vertical or sheltered surfaces.12

Common nesting locations include:

• Caves and Rock Faces: Many species attach their nests to the walls of caves or behind waterfalls.13
• Man-made Structures: Swifts frequently nest in chimneys, wells, tunnels, and buildings.13
• Trees: Some species build nests inside hollow trees.13
• Vegetation: Certain swifts, such as the Asian palm swift, attach their nests to the underside of hanging palm leaves.13

While most true swifts build nests, there is significant variation in construction. Some species create elaborate, tunnel-like structures, while others build simple, shallow cups or brackets. In contrast, the white-naped swift of Mexico is known to build no nest at all, instead laying its eggs in a depression on bare sand found on ledges deep within caves. Additionally, swiftlets are notable for constructing nests made primarily or entirely of hardened saliva.324