Once or twice a year we are blessed with a visit from cedar waxwings. They travel in flocks and normally make a soft zzzz-ing sound. What I heard this day was their call to the flock. They eat mostly berries and my previous exposure to them was one day when they cleaned out berries from my two Foster holly trees in about 5 minutes flat!
Again, I can't take credit for the photo -- too high and far away. If you want to know more about birds go to All About Birds (www.allaboutbirds.org).