What does a heron have under his kilt?

High, and I mean very high, in a conifer, were two white faced herons. No where near the sea, although as the heron flies I suppose it was about a kilometre. They appeared to be feeding on something or were they feeding a chick. It was just too hard to see.
Anyway I caught this one getting all fluffed up.

I was undecided how much to crop so in extras is the original and first crop. I could hear a voice in my head saying "what is the photo about? The bird or the tree?"