New in 2015, you'll find a widget on the side of the page to help you identify your Wisconsin backyard birds. Just enter a color and a bird type. For example, you have a red finch like bird come to your feeder, and you'd like to find a list of likely birds; just select "Red" and "Finch or Sparrow" and then click "Find Bird". A list of birds will appear. Click any of the names to be taken to the Cornell Lab of Ornithology's article on the species.
Please note, this is version 1.0, I'll add other birds to the tool as the year goes on. This first version covers 36 different species likely to be encountered in your yard.