Spotting black-crowned night herons in Tokyo

I was going for a run the other day, and spotted a rather interesting looking family down by the river. It didn't look like anything I had ever seen before - and a quick Google revealed it to be a ゴイサギ or black-crowned night heron. It seems they are usually more active at night and spend the day hiding away in trees so a daytime sighting is less common. I'd never seen one of these guys before, and I figured this might be a rare opportunity so I ran home, grabbed my camera and walked all the way back to where I had spotted them at the river - which took about 30 minutes. But luckily they were still hanging out. It seemed the male was fishing. And the female was just content to preen her feathers and give me the evil eye. The male had a long white feather coming out of its head - I knew from seeing little egrets that this is something they get during breeding season so I suppose this heron has something similar going on. But he has such vivid red eyes! I wonder if it's to help it see…