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
Edible bird's nest in colour, but there also exists a red version, sometimes called "blood" nest. The Chinese believe that it promotes good health, especially for the skin. The nests have been used in Chinese cooking for over 400 years, most often as bird's nest soup. The Chinese name for edible bird's nest, [""], translates literally as "swallow's (or swift's) nest", in Indonesia called ""sarang burung walet"" and often serves as a synonym for bird's nest soup. However, 燕窝 ["yànwō"], strictly speaking, is the uncooked nest. The best-known use of edible birds nest is bird's nest soup, a delicacy in Chinese cuisine. When