What contribution do birds make to mankind?

Birds can kill pests: wild birds provide a lot of meat, eggs, down and feces for human beings. Birds provide people with raw materials such as down and decorative feathers every year, as well as various light industrial products, toys and handicrafts processed by them. Bird droppings contain a lot of nitrogen and phosphorus compounds, which is a high-quality organic fertilizer.

Extended data:

The relationship between birds and people is very complicated, which varies from time to time, from place to place and from specific situations. For example, birds that specialize in eliminating agricultural and forestry pests are beneficial birds, but they also eat beneficial insects. And strictly speaking, just knowing how many pests it eats a day is not enough to determine the benefits brought by birds. It is still necessary to find out whether the number of pests in nature is really suppressed by the breeding of these birds.

Some birds save energy and kill a lot of pests in spring and summer, but they will spoil crops when sowing in spring and harvesting in autumn, and feed on weed seeds in the field in winter. Therefore, "benefit" and "harm" are relative, and there is no absolute beneficial bird or absolute harmful bird. Despite these complicated problems, after in-depth research by ornithologists, it is agreed that all birds existing today, with a few exceptions, are beneficial or not obvious, and beneficial birds account for the vast majority.