I am looking to adopt a rooster and a chicken and found this ad that states: They have gained their adult feathers recently, and are pretty much full grown at under 1 pound. I was wondering if anyone knows how much bigger they will get? She claims that they are about the size of a dove and won't get much bigger than that but my mother is telling me that they are going to get much bigger. If someone knows the answer I would appreciate it. Also, she claims that they just "peep" and won't make any other noises. To my understanding roosters crow and get very loud.