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For a lone potoo, or a brooding adult with a potential predator close to the nest, the bird attempts to avoid detection by remaining motionless and relying on camouflage. If ineffective, the potoo breaks cover and attempts to intimidate the predator by opening its beak and eyes wide open while vocalizing or simply flies out of reach.
Altricial birds are less able to contribute nutrients in the pre-natal stage; their eggs are smaller and their young are still in need of much attention and protection from predators. This may be related to r/K selection; however, this association fails in some cases. [18] In birds, altricial young usually grow faster than precocial young.
Predators of eggs and nestlings include turkey vultures (Cathartes aura), common ravens (Corvus corax), and American crows (Corvus brachyrhynchos). Red-tailed hawks ( Buteo jamaicensis ), American black bears ( Ursus americanus ), and raccoons ( Procyon lotor ) are known to take larger nestlings or fledglings, and in the latter predator, many eggs.
At present, the greatest threat to their survival is predation by invasive mammalian predators. The vestigial wings are so small as to be invisible under their bristly, hair-like, two-branched feathers. Kiwi eggs are one of the largest in proportion to body size (up to 20% of the female's weight) of any order of bird in the world. [7]
Sandhill cranes defend themselves and their young from aerial predators by jumping and kicking. Actively brooding adults are more likely to react aggressively to potential predators to defend their chicks than wintering birds, which most often normally try to evade attacks on foot or in flight. [37]
The common buzzard is an opportunistic predator that can take a wide variety of prey, but it feeds mostly on small mammals, especially rodents such as voles. It typically hunts from a perch. [5] Like most accipitrid birds of prey, it builds a nest, typically in trees in this species, and is a devoted parent to a relatively small brood of young. [3]
Birds in the south east of New Guinea are sometimes separated into a proposed subspecies, P. d. monticola, but the differences are very slight and the supposed subspecies are generally regarded as inseparable. [10] Pitohui, the common name for the group and the genus name, is a Papuan term for rubbish bird, a reference to its inedibility. [11]
They are also featured prominently in the lyrics of Joanna Newsom's bird-heavy fourth album Divers; the opening track "Anecdotes" name-checks four different varieties (Rufous, Whip-poor-will, Star-Spotted and Sickle-Winged) and the final track ends with a repeated radio transmission to the fictional soldier Rufous Nightjar.