It was a Blue Heron (more like a grubby brown/grey
herron) The ******* was HUGE like a 747. I was at my neighbors house
a block a way and he said a big blue Herron just flew by and I know
where he is going. I ran home and he was standing next to my pond and
at least 3 feet tall.
So much for my theory that it can't be a Heron! Well I put up some
netting and left a little spot open in the shallow end so small birds
can get a drink, hopefully that will work. Damn the bird was huge. He
did eat a lot of my mosqito fish which is o.k, after the initial
attack the goldfish got real smart, real quick. How he manage to find
my little pond is beyond me.

I had a similar experience recently. 15 years with no net and no losses, and no
large bodies of water nearby, then a dozen new koi missing (and those had been
tank raised for a year to put on size). One time I was on the deck 20 feet from
the pond and the heron flew over the house behind me, about 5 feet over my
head; and then aborted his landing when he saw me. The rush of air on his wings
was amazing! Scared us both!

I wasn't happy about the net but sure enough I don't 'see' it anymore, after a
few weeks.

I have birdbaths so am not worried about birds but I wish the bats could still
drink from the pond...