Cornell Lab of Ornithology: What Bird is Singing? Ask the Merlin Bird ID App for an Instant Answer . “Hear a bird singing? Today with the free Merlin Bird ID app from the Cornell Lab of Ornithology, you can make a quantum leap in bird identification just by holding up your phone. As Merlin listens with you it uses AI technology to identify each species like magic, displaying in real time a list and photos of the birds that are singing or calling.”