Ken --
That's what so neat about rainbows in ponds -- you never know what they'll try to eat next!
Seriously, I wanted to ask: do you have a significant snail population in your pond? For some reason, rainbows really like snails.
I once had a very abundant snail population in my pond. No more. They rainbows really cropped them down. I still have some. A friend of mine is an entomologist and he did some sampling a couple times last year and turned up a few but he had expected to find more. When I told him about the former abundance of snails, he said he wasn't surprised that the rainbows had worked on them.
So, my best guess -- and it's only a guess: there were some small snails colonizing in the downed pine trees, and the trout found 'em!
Only other possible thing I can think of -- sometimes hatchery rainbows go through a search and sample phase in acclimating to a new environment. Their image search for food is still pretty much pellet-oriented. But if they are not finding many, they will likely sample sundry other items/critters that might be food.
A biologist told me once that a lot of stocker rainbows in public waters that don't get caught right away can wind up starving or succumbing to disease relating to starvation or malnutrition -- unless they luck into a successful (nutritional) feeding regimen. It was interesting in that he noted almost all rainbows somehow recognize midges as food -- apparently because that's a type of insect that can be found in hatchery rearing ponds and even some raceways.
So, my two guesses: they were working over some snails, or still in some kind of search mode.
It will be interesting to hear more ideas/thoughts from other folks with trout ponds. -- Mike in Lexington, VA
