I think I have a fox in my garden

I haven't seen him, but I hear him calling every evening after dusk, and sometimes in the early morning too. This isn't the vixen's mating scream which you often hear at this time of year. It's a rhythmic, high-pitched triple bark that sounds more like a bird of prey than a mammal.

I guessed it was probably a fox because they are very common hereabouts, so I just googled "fox bark" and found a video that includes the sound. It's a contact call apparently.