Name that animal

At 3:30 this morning, Alex and I woke to this sound in our backyard. It was extremely loud and the darn thing did it for a good 10 minutes. I couldn't see it well but I am thinking it was a fox.

Does anyone know if that's right? I've never heard this noise before!

You can't see anything on the video as I was shooting it from my bedroom window into the darkness outside