An aid to identifying North American birds by sight or by sound designed to help people participate in nature survey and monitoring programs. You can browse lists of species found in a particular region. Free registration lets you develop your own custom list of species for study and then quiz yourself, based on songs or photos or both. As a registered user you can also submit your own photos or sound recordings. If you need a lot of scientific and habitat data about a particular bird, this site is not for you. But if you want to identify that bird that’s been vying with the squirrels for your bird feeder seed, this site is for you.