Red-breasted geese nest in tight knots around the nests of peregrine falcons, benefitting from the protection that the bird of prey offers. The peregrine does not prey on the geese and their young. In return, the loud alarm calls of the geese alert the peregrine, which has its own chicks to protect. The swooping vicious attacks of the peregrine falcon soon deter the fox from coming any nearer. The rufous naped wren builds next to wasps' nests for protection.
Some birds do without a nest altogether.
The Emperor penguin, which breeds in the middle of the Antarctic ice cap, where temperatures drop as low as -40C, is the only species of bird to lay its eggs directly on to snow. There are other birds that dispense with every convention of home making and parenthood, and resort to cunning to raise their families. The cuckoo is the best known brood parasite, an expert in the art of cruel deception. Its strategy involves stealth, surprise and speed. The mother removes one egg laid by the host mother, lays her own and flies off with the host egg in her bill.