Kangaroos - Faces in the Mob

I'm slowly getting through the collection of VHS tapes I got from Reg's office. The latest one was this guy about kangaroos. There was some anthropomorphizing and what not, but it was pretty interesting. The filmmaker's knew 15 years of history of this mob of kangaroos, so knew that one new mom had lost all 8 of her previous offspring, and were coloring their comments about her filmed mothering skills (or lack thereof) based on that. Her joey died on film. A different mom with a better record (2 for 2) went 3 for 3. Also apparently kangaroos determine the sex of their fetuses and have females when they are young to build a family and have males when they are old as the males leave the locale when they mature. Ain't mother nature crazy?