K good! I have some going on 2 and I'm getting a little worried. :S Sometimes mine will die for no reason. 1 got really sick and weak and the other 2 just died unexpectadly.
The AVERAGE Chicken lives less than a Year since Most Broilers are finished before 3 months of age, and Laying hens are disposed of after thier peak efficiency, so they last only slightly more than a year. Those that are raised as Backyard Flock Birds make up a very small percentage in the chicken world, so the few OLD birds hardly effect the average age of chickens.
About half of my flock contains birds over 4 years old. Most of mine seem to make it to 8 or 9. I have an old one-eyed sussex with no leg scales, and missing 1/2 a toe (Due to her previous owners neglect of scaley leg mite) that I think is between 7-9 years old. She was elderly when I found her, and I've had her for about 3 years. I have heard that they can live into thier twenties, but none of mine have lived that long. Also, does anyone know if bantams are more long lived? Like little dogs live longer than big ones?
I read one post on BYC that said one chicken was 10 years old. I do not know if she still laid eggs or not. Their production begins to decline more rapidly after their 3rd year it seems.