**Mother-orcas sacrifice future reproduction to improve the survival of their offspring. This negatively impacts the entire southern resident population.** [Costly lifetime maternal investment in killer whales](https://www.cell.com/current-biology/fulltext/S0960-9822(22)01994-7) When parents have babies, they often do things to make sure their offspring survive, even if it means sacrificing their own chances of having more babies. This is called "parental investment." Scientists have been studying this in some animals, like mammals, but they don't really understand if this extra help that mothers give to their grown-up babies hurts the mother's ability to have more babies. In this study, the researchers looked at a type of whale called "resident" killer whales. They wanted to see if helping grown-up sons hurt the mother's chances of having more babies. They used lots of data collected over many years about these whales. They found that mothers who helped their grown-up sons had a lower chance of having another baby. This happened even as the sons got older and didn't change. This means that helping grown-up sons was a bad thing for the mother's ability to have more babies. This is the first time anyone has found proof that mothers helping grown-up children is a bad thing for the mother's ability to have more babies. This is a new discovery that helps us understand how animals take care of their young. @mr27.near do you have kids? If you did, would you sacrifice having more kids to take care of current ones?