Birds tend to sleep in the same areas they inhabit during the day. To protect against predation, many birds will sleep in a way that enhances their security within this habitat.
Water birds will sleep sitting or standing in the water or on predator-free islands. Many other birds, such as horned larks, quail and sparrows, sleep on the ground in dense vegetation.
Birds which nest in cavities tend to sleep in their trees, chimneys, or in nest boxes far away from many predators. It is no accident that the majority of bird species, including those that are not regular tree-dwellers, prefer to sleep in trees or dense shrubs. There they are out of reach of predators which cannot climb and are warned by vibrations of other carnivores long before they are a danger.
Sleeping habits can also change with the seasons. For instance, territorial birds often sleep in their territory (including on the nest) during the breeding season but thereafter may sleep communally in large roosts. Woodpeckers often will excavate sleeping cavities in the fall rather than sleep in the older breeding cavity.
Ruffed grouse, which usually prefer dense conifer cover in the warmer seasons, will often burrow into snow in the winter to avoid predators such as the northern goshawk.
