Our long driveway crosses through the neighbors property and ends down by a spring choked with reeds and berry brambles. I heard a very strange sound... a lot like a bullfrog except it ended with a distinct chirp. It was in the underbrush and didn't sound like a bird. And it started with a rusty hinge type of sound with distinct ticks.
Thanks to Kiswara and Trey for help with sounds. It was kinda like this but ended with a chirrup.
I think we have otters at the spring again! I encountered an otter before, two years ago I think (not enough time to search back and find the LJ entry at the moment), and saw her head that direction.
Now it sounds like river otters are back at our little waterway. Hooray! :D