If you haven't seen a Hairy Woodpecker you may have heard one. It's tap-tap-tapping echoes through the woods as it searches for insects.

Or, you may have seen this black and white bird, with a red cap on the back of it's head, flitting about looking food. But how can you tell it's a Hairy Woodpecker and not it's virtual twin, the Downy Woodpecker. Here are a few key things to look for to identify the Hairy Woodpecker:

• It has a longer beak where the Downy's is only about a third of the width of its head.
• The Hairy Woodpecker is also bigger. A Downy is closer to House Sparrow size.
• The Hairy also has all white outside tail feathers and the Downy's are spotted with black.

Still, It may take some time before you can distinguish the difference between the Hairy Woodpecker and the Downy. While they often occur together, you might not get the chance to see them side by side. Here's a guide comparing these two woodpeckers.

Although the Hairy Woodpecker is still very widespread and fairly common, it is thought to have declined from historical levels in many areas. Loss of nesting sites with cutting of dead trees in forests is one potential problem. Standing dead trees is a good place to start your search if you are looking to spot this dynamic bird.