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 Nest (aviary) to achieve captive breeding of the bird, which had been a traditional symbol of freedom, characterized by not being able to survive outside its native habitat. The origins of the Nest began in the era of the sixties, when the veterinarian Jesús López Estudillo decided to buy land with eight acres containing 10,000 trees and plants devoted to research, conservation and breeding of endangered birds. His passion for these animals led him to bring together endangered birds and perform several experiments to recreate their habitat so they could be kept in captivity. Thus, he could observe their behavior and thereby