Another welcome sign of spring

I was happy to spot a frog swimming in our pond today. We've been concerned about them overwintering in the pond since we lost all of the adult frogs the previous winter. This year we put pipes in the pond and checked every day that they hadn't iced up. When they did, I added hot water to the pipe. I think the key is to keep an air hole open. Another reason at least one frog survived might be that we cleared out more of the vegetation in the fall so there wasn't as much decomposing vegetation to take up the oxygen in the water. We'll have to look into this more. I'll be happy to see the other dozen or so frogs appear. It's a miracle they can survive all winter in that icy water!