Don't feel bad, I might have done the same thing. Hey, even on our Planet Earth DVDs, there is an extra clip showing that even though their policy is to never interfere, they did with this baby penguin that got stuck in a hole.
Interesting, that's kind of the approach I take. I would
never go on a "crusade" "saving" wild animals in the backwoods of Alaska, nature is nature. However, it seems there's a difference when it's happening RIGHT in front of you. The way I figure it, if nature did NOT want me to intervene, it wouldn't be happening right in front of my face.
To address the point brought up by the OP, by trying to intervene, I don't think you did anything morally wrong. If it's truly the fate of these ducklings to become GBHeron food, it will happen tomorrow or the next day- you get the idea.
As far as my experience working in a bird rehab, we have had GB Herons. They tend to be fairly mellow around humans. I had not heard of any of the rehabbers being seriously hurt by one. On the other hand, they considered the cormorants to be much more dangerous. In my personal experience, I would agree the d.c. cormorants have sharp bills and are FEISTY !!
I don't think you took a great risk by engaging the Heron.
As for cabirds talking bout someone who was drown by a swan, that's pretty crazy! but I know swans are MUCH more aggressive than Great Blue Herons. And much heavier! The GB Heron, as large as it is, only weighs about 6-7 pounds !! A Mute Swan can weigh 20-30 pounds. But still, I weigh over 200+ and can turn a 30 pound bird into 20 pound Thanksgiving Dinner in about 8 seconds. And I'm sure Creeker could do it in 2