joer wrote:
The most positive way to distinguish between them is the under side tail feathers...Hairy's are completely white and Downy have horizontal bars.
Of course its not possible to see them at times, so size and beak length are the only indicators. In this image its clear.
Once I shot a Downy in the rain with wet feathers around the beak and I could have sworn it was a hairy.
My aging eyes do not always co-operate, particularly with viewing the underside so I am at the mercy of a descent shot. I see them occasionally, but we are inundated with the Downy and I keep waiting!