Walking through Juanita Bay Park with mum, we saw and heard a small bird nearby.  When we got a clear look at it, mum asked what it was.  Now, I am not a bird specialist, but I do have two things on my side.  One, I can get a photo of it and two, I have a very big book of North American birds at home so we can look it up afterwards.  Mum thought it looked like a wren based on the shape and angle of the tail and I thought she had a good point.  Sure enough, get to the book at home and it was indeed a marsh wren.  Cute little thing.