Just recently (yesterday, actually) I saw my first ever red-breasted nuthatch at my bird feeders. The same day I thought I had heard one, but since they are fairly uncommon around my area, I decided that probably wasn't what I heard. It turns out that later that day I was watching my feeders and a little female red-breasted nuthatch lands and the feeders, grabs a nut, and quickly darts away to the birch tree. The male and female were also at my feeders today. Infact, I was about to fill my feeders, but since I didn't want to scare away the red-breasted nuthatches, I waited until they were gone and I went to fill the feeders. I was just pouring seed onto the hanging tray feeder when I heard the distinct 'honk' of the red-breasted nuthatch. A little male red-breasted nuthatch hopped around the side of the tree, right up to the feeder I was filling, grabbed a peanut and flew away! That was the closest I have ever gotten to a wild bird! Just like with the larger relatives, the white-breasted nuthatches, you can tell the male from the female by the color of the cap. In both instances the male has a black cap and the female has a gray cap. I had both male and females of the white-breasted and the red-breasted varieties.
Below are two of my photos:
You can tell in the above photos that the bird in the top photo is a male because of a black cap while on the bottom photo the bird has a gray cap, meaning that the bottom bird is a female. Actually, the female in the bottom photo was on the gutter, and it would look around for a few seconds then hop inside the gutter for a little while and then pop back up again and once more look around for a few seconds before hopping into the gutter again. It did this sevral times.
Not much more to say other than this: They really are smaller than they look when you get up close to them. They are very small indeed. Very tiny, noticeably smaller than the white-breasted variety.