Who's that singing? As fall migration arrives, apps that ID birds by sound have taken off

For many bird watchers — novices and experts alike — this fall's migration will have a soundtrack. Merlin, from the Cornell Lab of Ornithology, is just one popular and free app that can identify birds just by their sound. You don't have to see them to realize from their calls just how many different kinds of birds surround you. Birding’s popularity soared during the pandemic, when people were eager to get outside. Merlin's popularity grew. But Cornell numbers show it grew even more when the Sound ID feature was added in June 2021. They say more than 7 million people now use the app worldwide. Similar popular apps include ChirpOMatic, Picture Bird and Smart Bird.