These will be queens which have successfully survived the winter and are now seeking nectar and pollen from Spring flowers. Migrant birds. Chiffchaffs are usually one of the first migrant birds to arrive in March and they can be heard singing their names in a repetitive ‘chiff chaff’ song from the tops of trees. Cuckoos, swallows and house martins usually arrive in April and swifts may not appear until early May.