Swallows live in Nanyang Archipelago, where winter is like summer, and then fly to coastal gravel areas and estuarine sandbars in Taiwan Province Province in summer to breed. This kind of bird is called "summer migratory bird". Take Guangdong as an example. Migratory birds such as cuckoo and swallow breed in Guangdong in summer, fly to warmer areas such as Southeast Asia in autumn for wintering, and return to Guangdong for breeding in the following spring. This is the "summer migratory bird".
Reasons for expanding data migration
Swallow is a famous summer migratory bird in China. Migrate to the north in early spring and spread all over the country in summer. After breeding, they move south in groups and overwinter in India, Nanyang Islands and Australia.
Swallows feed on insects, and have always been used to preying on flying insects in the air, but they are not good at searching for insect food in cracks in trees and on the ground. They can't omnivore berries and seeds like grouse and Thunderbird, eat leaves in winter (some conifers don't shed their leaves even in winter), and they can't dig up larvae, pupae and eggs of latent insects like woodpeckers and woodpeckers.
There are no flying insects for swallows to prey on in winter in the north, so they migrate.
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