original: the females have the unique ability to delay birth of their baby until their previous joey has left the pouch .
simplifications: untill the previous joey leaves the pouch , females are able to delay the birth of their baby the females have the ability to delay birth of their baby until their previous joey has left the pouch . the females have the special ability to delay birth of their baby until their previous joey has left the pouch . the females have the unique ability to delay birth of their baby until their previous joey has left the pouch . the girls have a special ability to put off birth of their baby until the previous baby has left the pouch . the females have the special ability to wait to give birth until their older joey has left the pouch . the females are able to delay birth of their baby until their last joey has left the pouch . the females can delay the birth of their new baby until the last one has left their pouch .