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
Capital city of one constituent nation will also be the capital of the state overall, such as London, which is the capital of England and the United Kingdom. Similarly, each of the autonomous communities of Spain and regions of Italy has a capital city, such as Seville or Naples, while Madrid is the capital of the Community of Madrid and the Kingdom of Spain as a whole and Rome is the capital of Italy and the region of Lazio. In the Federal Republic of Germany, each of its constituent states (or "Länder" - plural of "Land") has its own capital city, such