I also got a barred rock back in April and was starting to worry as September came and went. Mine actually just started laying last week, making her about 27 weeks old. I have heard that is somewhat older for this breed to start laying, but now that she is she's laying every day, and her eggs...
Yes, turkey vultures (at least here in Eastern PA) will kill and eat chickens. I lost an adult bantam to one a couple of weeks ago. I didn't actually see the attack, but when I came outside a large vulture was in the process of eating the body. Since that incident, I have been keeping a much...