Hey Greenthumbs! You have tree frogs! AWESOME! I know we have them in Michigan, I saw one once in the woods up North. I have never seen them in the pond.
Esther, we don't have much luck with frogs either. I found a big one dead in the skimmer a couple weeks ago. It had been there awhile, so I don't know what happened to him. We find they are either taken or wander off. If htey stay, most don't make it through the winter. I think I had one survive this year (probably the poor thing that ended up in the skimmer). It always makes me feel like a killer. We didn't let the kids bring frogs to the pond this year. We told tghem if they show up we'll let them stay but we aren't bringing them to have them die.
We went to a garden center in Brandon Mi. They had a zillion frogs. The owner told me that they never had luck overwintering until they got enough "gunk" on the bottom for htem to overwinter. Well, let me tell you. I have never seen such a case of string algae. It was probably a foot thick everywhere but where the waterfall drove it to the sides. It was really awful. Definately a frog pond, not a fish pond. You could not see water. I bet it's a mosquito nirvana.
Have you heard about frogwatch? In the spring, one selected day, you go out and count how many frogs you hear within a certain range from your house. It's through the national wildlife federation. There is a fungus killing off huge numbers of frogs and they are really in need of count people for the study. (I'm going to check it out.) My daughter's National Geographic kids magazine just had an article on how this fungus is wiping out rainforest frogs. Researchers are capturing frogs that don't have it and putting them "in hospital" to try to see if they have a certain resistance to it and if they can save them. I'll see if I can find a link to the article to post.