Nature on our doorsteps: Nest building
Different species of birds build different types of nests.
Some are very simple constructions. The nests of Rooks tend to be a jumble of twigs and sticks caught between the branches of a tree.
Blackbirds, Robins, and Thrushes build neat, cup-shaped nests woven from grasses and mosses. These are lined with mud and soft feathers.
Other birds, like the Long-tailed tit, build quite complex structures. This bird uses the sticky egg cocoons of spiders to glue small pieces of moss together into a rounded ball.
They line the inside with hundreds of soft feathers and they cover the outside with pieces of lichen to camouflage the nest against the bark of the tree.
Baby birds do not see how their parents constructed the nest in which the chicks develop.
It was always assumed therefore, that when chicks grew into adulthood and began to build their own nests, they simply relied on deep-buried genetic memory or instinct to construct the right type of nest for their species.
It is now thought that while a degree of instinct is certainly involved, many birds do in fact also learn by watching other birds of the same species.
They also learn by trial and error, improving their building techniques if the first nest fails or when they are lucky enough to rear a second brood.