The Lark sings as it flies in the air, the Quail sitting on the ground; others, on the boughs of trees, such as: the Canary, the Chaffinch, the Goldfinch, the Siskin, the Linner, the little Titmouse, the Woodwall, the Robin Redbreast, the Hedge Sparrow and so on.
Source: tatoeba (7315292)
Many of these classic methods are still used, with some modern improvements. For example, with the aid of special microphones and automated sound detection software, ornithologists recently reported […] that pine siskins (Spinus pinus) undergo an irregular, nomadic type of nocturnal migration.
Source: wiktionary