Agreed.Those tracks look big enough to be a large dog or a young wolf. I don't think it was any experienced hunter because then it would have eaten more than just one bird or at least cherry picked it's favorite parts from multiple birds. It had to have been a pack of dogs or a immature group of wolves or coyotes, any other pack of animals would have eaten the majority of the birds killed.
I have seen dog prints that big. They typically belong to the large and heavy breeds such as Mastifs, Mountain dogs, Dogos, Rotties, Bernards, etc.
I very highly doubt that it was a young wolf; they tend to travel with the adults whom would have consumed all of the carcasses.
My bet is on a couple of large breed dogs. Maybe escaped from a breeder, probably all owned by the same person.