They do sound like bowling balls dropping!
I always worry about my little feather footed porcelain free ranging because of the hawks, eagles & owls we have around here. She's not the quickest, but she knows it & makes sure she's never out in the open by herself. It's actually kind of funny to watch her when she notices she's alone - she either high tails it back to the covered pen or over to Lila or Sparta. I've noticed that Memnoch is hyper vigilant with his warning noises & even the rabbits freeze when he starts wailing. The five light coloured birds I have are almost always on the lookout for death from above, to be honest. The peafowl are pretty vigilant, too. They chase the pigeons away from the chickens & notice things well before I do (like the neighbors' giant pit bull mix dog being in our field & making its way toward my free ranging flock this evening).
I always worry about my little feather footed porcelain free ranging because of the hawks, eagles & owls we have around here. She's not the quickest, but she knows it & makes sure she's never out in the open by herself. It's actually kind of funny to watch her when she notices she's alone - she either high tails it back to the covered pen or over to Lila or Sparta. I've noticed that Memnoch is hyper vigilant with his warning noises & even the rabbits freeze when he starts wailing. The five light coloured birds I have are almost always on the lookout for death from above, to be honest. The peafowl are pretty vigilant, too. They chase the pigeons away from the chickens & notice things well before I do (like the neighbors' giant pit bull mix dog being in our field & making its way toward my free ranging flock this evening).