A kangaroo will mate again one to three days after giving birth to have a backup embryo
Kangaroos and related animals often keep an embryo dormant in the womb while they suckle another baby in the pouch. This fact might sound weird, but it makes a lot of sense when you think about it. There is nothing more important to these animals than having healthy offspring.
Kangaroo will just start to mate again one to three days after giving birth. The newborn will remain in the pouch as long as it thrives. What is more, the mother kangaroo can put its newly fertilized embryo in a state of dormancy. That way, it has a backup.