For birds, siblinghood can be a matter of life or death

MAY 1, 2024 5:00 AM ET
Nell Greenfieldboyce

Human sibling relationships can get pretty complicated, but in the world of birds, siblings can be so impactful that their existence can mean the difference between life and death.

That's because avian nest-mates sometimes forge close, collaborative relationships that last their entire lives.

Other times, after an egg hatches, a baby bird might immediately get killed by its older brother or sister.

That depressing alternative is what fascinated David Anderson of Wake Forest University when he first noticed it a few decades ago. Back then, he was working as a research assistant in the Galápagos Islands, and he'd often pass by nests on the ground made by large white and black seabirds called Nazca boobies.

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