The Cornell Lab’s Project FeederWatch is a November-April survey of birds that visit backyards, nature centers, community areas, and other locales in North America. You don’t even need a feeder! All you need is an area with plantings, habitat, water, or food that attracts birds. The schedule is completely flexible. Count your birds for as long as you like on days of your choosing, then enter your counts online. Your counts allow you to track what is happening to birds around your home and to contribute to a continental data-set of bird distribution and abundance.
(text taken from https://feederwatch.org/about/)
For more information, go to the FeederWatch site.