Old kangaroos have worn molars so they dont bust open the plant cells, thus much of what they eat passes through undigested. Eventually they just eat and eat but keep losing condition. (Same with many herbivores (eg koalas) which do not have continuously growing molars. So at that time the suburbs are vital for them because of the longer softer greener grass.
@DonFletcher Thanks Don, we are happy to help him with the grass, it's pretty good for this time of the year with all the rain we have had. We always have water available in normal bird baths and ones on the ground also. He can visit anytime and feel safe, we never go near to him and he always looks relaxed.