a small bird perched on top of a red flower

To the untrained eye, downy woodpeckers and hairy woodpeckers look like two identical species. Hairy woodpeckers are larger than their downy look-a-likes, with a longer bill. One of the more reliable give-aways is that downy woodpeckers have spotting on their white outer tail feathers, whereas hairy woodpeckers have unmarked tail feathers.