Reproductive System
-Females become reproductively mature at 18-24 months while males don't mature until 36 months
-Males fight to reproduce so they usually don't get to until they are 7-10 years old when they are large enough to compete
-The males fight be leaning back onto their tail and kicking their very strong legs at each other, this is known as "boxing"
-No breeding season, they mate year round
- A baby kangaroo, also known as a joey, is born out of the birth canal, and then climbs up her mothers fur into  her pouch
-The joey will stay in the pouch for about 8 months, drinking from teat inside the pouch
-Mothers can have multiple young at once, for example one could be in the pouch and another still developing in uterus
-Females also have two vaginas and two uteruses so they can have more children
-Because of this, females are in an almost permanent state of pregnancy, but have "embryonic diapause" meaning they can suspend development of next embryo until conditions are favorable

This is a picture of two male kangaroos "boxing"