Common nightjar. Unusually for birds, nightjars perch along a branch, rather than across it. Nightjars are nocturnal birds, related to frogmouths, oilbirds and potoos. They are sometimes known as goatsuckers as they were once thought, mistakenly, to suck milk from goats. Some American species are called nighthawks. Active in the late evening, they prey on moths and other flying insects, capturing them in their short bills. They fly silently, and perform rapid twists and turns in mid-air in pursuit of prey.
On the ground
Nightjars have short legs and small feet: they hop about awkwardly on the ground. Their wings are long and pointed. Their brownish-grey plumage looks like bark or leaves, which helps to camouflage them. During the day, they lie still on the ground.
Nightjars lay their eggs on to bare ground: no nests are built. They are said to carry their eggs or chicks in their mouths away from danger, but this is not known for sure.
The common poorwill is the only bird known to hibernate.
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