Cedar Waxwing Courtship, Passing the Berry Back and Forth

[Donkees]

6. Bird Embryos Vibrate to Warn One Another of Danger before They Hatch

The egg-bound developing animals are more attuned to the outside world than previously thought

BY JENNIFER LEMAN

Before they hatch, developing baby gulls seem to prepare for the worst when they hear the piercing predator-warning calls of nearby adults—and may also alert their less-developed nestmates.

Yellow-legged gull embryos exposed to the warnings of adults and neighboring embryos that had not been exposed to the sounds both displayed a series of behavioral and physiological changes when newly hatched, according to a study published Monday in Nature Ecology & Evolution. By vibrating, the embryos exposed to the call appeared to transfer knowledge of the threat to the others in their nest—the first time such a behavior has resulted in observed changes to clutchmates.

https://www.scientificamerican.com/article/bird-embryos-vibrate-to-warn-one-another-of-danger-before-they-hatch/