A new reason to take the phone on the dog walk

The flamboyant cardinal is a loudmouth and the tiny Carolina wren is a boisterous chatterbox.

You'll start to recognize all the resident birds — and occasionally a stranger on the wing — in your neighborhood with the magical Merlin Bird ID, a free app from the Cornell Lab of Ornithology.

Merlin is a breakthrough for both serious bird watchers and for people just strolling through a park. It includes a feature called Sound ID that listens through the phone's microphone and names the birds singing around you as they sing. Even when there is a chaos of birds in the park, the app can identify every separate song. You don't even need a cell signal to discover the birds around you.

Sound ID covers 2,066 species. That number goes up twice a year, on recordings made by people holding up their phones on their own walks.