eBird by Cornell Lab
Cornell Lab of Ornithology
Birds of Europe Field Guide
Ecosystema
Audubon Bird Guide
National Audubon Society
Merlin Bird ID by Cornell Lab
Picture Bird - 撮ったら、判る-1秒鳥図鑑
Next Vision Limited
iNaturalist
GoBird - Guide to Nearby Birds
Tony Gentilcore
Birda: Birding Made Better
Birda
BirdNET
Stefan Kahl
Collins Bird Guide
NatureGuides Ltd