LOL! Yes tree frogs are incredibly loud! I had about 5-6 singing to each other yesterday evening in the back yard and I could hardly hear my family talking to me while out on the deck! They are really hard to find too. I have one that retires to a little ledge on the top of my shed every year.....same spot. He's so cute! I love going to sleep with my windows open so I can hear them, but sometimes, I just have to close the window 'cause they are sooooooo loud! They are pretty amazing little creatures. I think they are attracted to my backyard because I have several little water gardens. They deposit their eggs in the water. They are so sensitive to the presence of water, that if I go out to just water a few plants, they start singing! I don't know if they see the water, or just hear or smell it! Ain't nature grand? :)

Nope, the who in a great horned is a distinctive who with a deep tonal quality. This was definitely more of a child's slide whistle quality, more of a toot. I'm thinking it was a northern saw-whet as it most closely matches that tonal quality. Here is a link that might be useful: Listen to

Barn Swallows for sure. I responded to your other post; once Barn Swallows find a good place to nest, they tend to return. Generally taking down any existing nest will just have them build another. Is that a nest box? If so, you may have better luck removing that....but they probably will just build new.

Yep, colours work out. Today I had the male show up too. Both birds are walking very diligently through my flower bed in search of seeds. They make quite a different sound when startled.