I had a 34 inch female.. She just recently died... She was over 20 years old and produced babies every single year since she was three years old... thats a lot of babies.
They go into a slow decline when they start to die of old age.. It actually takes a few years.. the vertebrae start to fuse in the neck and they don't move very well, when they get old.. Eventually they just fade away, lose muscle tone and stop feeding