How do birds make a nest?

Birds are the ultimate nest-builders. Each different species has its own unique nest-building techniques and constructs these structures without ever getting confused. When the parent birds leave the nest to search for food, their offspring are completely defenseless. Their nests that are concealed with great skill in treetops, holes in trees and cliffs, or even amidst tall grass, provide a safe, hidden shelter for the chicks. Another purpose of the nests is to provide protection from the cold. Birds are hatched featherless, and since their muscles do not get exercised within the egg, they are relatively immobile and thus need nests to insulate them from the cold. Woven nests in particular trap body heat, providing warmth for the chicks—but constructing these structures is a detailed and difficult undertaking. The female builds the nest by carefully weaving grasses, twigs, and scavenged yarn over a fairly long period of time. She cushions the inside with feathers, hair and fine grass, thereby further insulating the nest. For every type of nest, finding the right building materials is essential. Birds can spend a whole day in their quest for the building materials their structure needs. Their beaks and talons are designed for carrying and arranging the materials they gather. The male bird chooses the location of the nest, and the female builds it. These nests’ features depend on the materials and techniques used in their construction. All building materials for their architectural masterworks must be pliable and compressible. Nests are built taking into account the elasticity, durability and toughness of the different materials birds use—mud, leaves, feathers, cellulose and the like. This increases the structure’s durability. Using plant fibers mixed with mud, for instance, prevents cracks from developing. First, birds mix the mortar from the materials they gather. One species that uses this technique is the cliff swallow, which builds its nests on cliffs and the walls of buildings, using mud as an adhesive to glue their nests together. They gather mud and feathers and transport them in their beaks to the construction site, where they mix mud with their saliva, smearing the mixture against the face of the cliff to form a pot-shaped structure with a round opening on top. This structure they fill with grass, moss, and feathers. Usually they build these structures in cavities under overhanging cliffs, to prevent rain from softening and thus destroying the nest. if you would like to read more about this, the site is: http://api.fmanager.net/api_v1/productDetail.php?dev-t=EDCRFV&objectId=8168 . I hope I helped you a bit.