Jun. 30—Is that the tweet of a titmouse? Or the chirp of a chickadee? After you download the app Merlin Bird ID, you can use your smartphone to identify sounds and match them to the birds in trees ...

I’m not a bird watcher, but I’ve become a bird listener ever since downloading a bionic ear app to my phone. It lets me enter a different world, one where I’m surrounded not just by chirping but by ...