The thing I noticed is that 'Kangaroo' covers a lot of very different sized/population holding animals.
There are fewer species of deer in America than there are species of 'Kangaroo' in Australia. From tiny little ones (1.4ft long/3lb) to 9-10ft long Reds (200lb).
Wikipedia does a better job than I
https://en.wikipedia.org/wiki/Kangaroo
