Merlin Bird ID is a highly-acclaimed bird identification app for mobile platforms, developed by Cornell Lab of Ornithology in 2014. Unlike any similar app, it's powered by eBird, the largest bird database in the world, and its mission is to educate and protect birds and nature. Best of all, it's completely free to use. So, it has been regarded as the ultimate tool for identifying birds through a variety of methods.

Bird: The Definitive Visual Guide is a comprehensive and authoritative book that provides a wealth of information about the fascinating world of birds. This visually stunning guide is a collaboration between renowned ornithologists, photographers, and bird experts, making it an ideal resource for both bird enthusiasts and casual readers.