<P> In the Victorian era, naturalists often collected bird's eggs and their nests . The study of bird nests is called caliology . </P> <P> Bird nests are also built by humans to help in the conservation of certain birds (such as swallows). Swallow nests are generally built with plaster, wood, terracotta or stucco . </P> <P> Artificial nests, such as nest boxes, are an important conservation tool for many species, however nest box programmes rarely compare their effectiveness with individuals not using nest boxes . Red - footed falcons using nest boxes in heavily managed landscapes produced fewer fledglings than those nesting in natural nests, but also than pairs nesting in nest boxes in more natural habitats . </P>

Where do the water birds make their nest or lay eggs