Guinea fowl are good alarm birds, but they'll be running for cover with the chickens. Peafowl and geese sometimes eat snakes. Geese help protect other birds from raptors if you're worried about the buzzards, though those don't usually prey on adult chickens. Ratites, (emus, rheas, and ostriches,) can help with foxes, but these aren't exactly hobby fowl. For foxes, your best bet would be to either keep them indoors, or get a reliable guard dog.
Not for my geese, I have had to pull a rattle snake out from under a nesting goose that would just sit there on her eggs while the rattler took an egg or two. No harm to the goose. Seen my Chickens and Guineas picking off a group of newly hatched baby snakes like it was a pile of worms. Rat snakes are beneficial in the barn, they do keep down small rodents and wild rabbits, they are also territorial that they keep the rattle snakes out of the barn. My new chicks are kept in tall water tanks and on my chest freezer until they older to go to perch and I have many areas that my birds can go to perch. I do try to find the balance because I appreciate not having any rattlers because of them. Nuisance behavior like being caught stealing eggs I relocate them with the snake stick. I would have to say chickens and guineas do more damage to the younger snakes then the geese
That is what my Raven started doing patrolling our skyway? At first I wasn't sure that is what it was, then a few years ago he brought his girlfriend to meet us lol.. and this year they have trusted us to build their nest in our horse barn.. I feel touched. Thats Oliver he adopted us many years ago
Your buzzards very closely approximate the American Red-tailed Hawks. This one of those deals where scientific names would help.
