Welcome to BYC. Glad you decided to join our flock. You have some great layers. Black Australorps are my favorite standard breed. I raised them for years (along with dozens of other breeds), and they are extremely hardy, calm and gentle (my children and granddaughter made lap pets of them), and excellent layers of large, brown eggs. Your hens appear to have a lot of missing back and neck feathers which is a classic sign of being overbred by roosters. I would suggest keeping your flock rooster free until you have enough hens to prevent it from happening again. The recommended ratio of roosters to hens is 1 rooster for every 10 hens. If you haven't done so already, definitely check out our Learning Center at https://www.backyardchickens.com/atype/1/Learning_Center. There is loads of useful information there. Please feel free to ask any questions you may have. We are here to help in any way we can. Good luck with your flock.