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 (horse) Hurdle. Throughout his career, he was known for being a difficult and temperamental horse, with a tendency to veer left when under pressure. Birds Nest was rated at 176 by Timeform in the seasons 1975/6 and 1976/7. At the time of his retirement he was the joint-third highest rated hurdler in the organisation's history, after Night Nurse and Monksfield and equal with Golden Cygnet. In their book "A Century of Champions", John Randall and Tony Morris ranked Birds Nest the ninth best British or Irish hurdler of the 20th century. Birds Nest (horse) Birds Nest (1970–1994) was a British-bred thoroughbred