Bird nest July to September), it is not in others, and the swiftlets are declining in areas where the harvest reaches unsustainable levels. Some species of birds are also considered nuisances when they nest in the proximity of human habitations. Feral pigeons are often unwelcome and sometimes also considered as a health risk. The Beijing National Stadium, principal venue of the 2008 Summer Olympics, has been nicknamed "The Bird Nest" because of its architectural design, which its designers likened to a bird's woven nest. In the Victorian era, naturalists often collected bird's eggs and their nests. The study of bird nests is
The Life of Birds steal eggs include toucans and currawongs. A number of strategies are employed to deter the thieves, as illustrated by the yellow-rumped thornbill, which builds a decoy nest atop its actual one, and the plover, which distracts marauders by feigning injury. Broadcast 16 December 1998, the penultimate installment concentrates on the ways in which birds rear their offspring. Having successfully incubated their eggs, the moment arrives when they hatch — and then the real challenge begins: feeding the chicks. Lapland buntings and dippers are shown doing so virtually non-stop throughout the day. The Gouldian finch has a further problem in that