Guess Who came To Dinner? An Uninvited Guest

When I had my pond built, I did a lot of reading about garden ponds. One thing reassured me was that my pond was probably too small to attract large bird predators, namely the Great Blue Heron. After all, the pond is only about 5 feet wide and 14 feet long, add a few feet for the gravel filter/waterfall. So, good, I would not need to invest in an anti-heron device (aka a plastic heron statue that makes other herons believe "this pond is taken!") or worry about my frogs being eaten. Shortly after my pond was built, like the next day, a frog found his or her way in, and we have had chirping frogs ever since.
A very large frog successfully overwintered in the pond this year. I was at the point of bestowing some affectionate name on him, when I came home with visiting nephews and niece in tow, to find this above uninvited guest, with the remains of froggie in his beak. The heron has been in the neighborhood, casing the pond for over a week, but this is the first we've seen him at the pond (probably because my dog Bob scares him off or chases him away).
Next stop: the garden center for a plastic, anti-heron device! That is, if I want frogs in my pond (a heron can clean out a pond in a few short visits).
He is a pretty impressive specimen of wildlife and was a pleasure to see so close, 'cept for the sorrowful remains of froggie. It's a bird-eat-frog world out there!
Happy gardening!