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
Birds Nest Foundation (NGOs) publicize their efforts, without sacrificing charitable donations that could otherwise be spent towards their respective causes. Based in New York City, Birds Nest Foundation's funding relies on donations, grants, and sponsorship. In summer 2010, Birds Nest foundation became an official public charity under section 501(c)(3) of the US Internal Revenue Code. Birds Nest Foundation works to educate students and adults about healthy lifestyles, proper diet, and the process of growing food. They serve as advocates to improve the nutritional value of school lunches. Their effort have produced a documentary film and two television shows, as well as an initiative