Scientists have discovered that middle aged male killer whales, or orcas, remain dependent on their mothers throughout their lives.  Once their mothers die, their risk of death within a year is increased by as much as 14 times.  Researchers speculate that this long period of attachment is the result of female whales having a long menopause, almost half of their adult lives females are unable to reproduce.   For this reason, mother whales take care of their males for an extended time.  Learn more here.

Image from animal.discovery.com