Taller than most seabirds, masked boobies live and breed in tropical oceans where they feed by making high-velocity dives. They also kill their own young.
In a new study subjecting Darwins evolutionary theories to some of their most rigorous scientific tests to date, biologist David Anderson at Wake Forest University found a curious irony: boobies kill in order to thrive.
"The common view of Darwinian natural selection is that it favors the evolution of parental interest in offspring," said Anderson, a member of the Wake Forest faculty since 1992 and reviewer for the National Geographic Society, National Science Foundation and several journals. "Parents that care for their kids raise the most kids and spread their genes most rapidly. However, in masked boobies and some other animals, siblicide is an integral part of reproductive success. Siblings engage in lethal battles shortly after hatching from their eggs."
Anderson said that parents are far from disinterested observers of the family conflict.
"Masked booby parents are actually facilitating and encouraging this early siblicide setting up a contest between the older and younger chick that only one is going to survive and stacking the odds in favor of their eldest," Anderson said. "In masked boobies, maximizing reproductive success is not about being caring and nurturing but making short-term sacrifices of their own offspring for long-term gain," he said. "This is more complicated than most people think Darwins theory about reproduction in evolution is. The bottom line isnt how many babies you have now, but the total number of healthy offspring over the long term.
"When you have more young in a brood than you can care for well, it may pay to pare off some young. These findings are an extreme example from nature of that point."