Yesterday I had a few questions on how I knew the difference between the male and female chickadee. I can't tell by looking at them, I was just able to figure out which was which by their actions. Here's a photo of the female in the nestbox, while she was in there the male came and fed her a caterpillar and I snapped his picture when he landed on a branch afterward. I actually have a photo of him holding the caterpillar which I may post at another time. The female flew out of the box after a while and the second photo from yesterday is what I took.