Baby Birds Are Able to Sense the Danger And Warn Other

Growing baby birds might be able to sense danger and “warn” other unhatched birds in the same nest about nearby predators, according to new research.

It seems like one of those mysterious, inexplicable things animals do, however pair of researchers from the University of Vigo in Spain laid out a very particular pattern of habits and found that it adjustments the direction of the birds’ development.

The researchers studied 90 yellow-legged gull eggs, divided into “clutches,” which is a term for all the eggs in one nest. They separated some eggs in a clutch and performed adult gull warning calls. As a result, the eggs began to move.

“Gull embryos alter their motility when exposed to alarm calls emitted by adults, an impact that causes the egg to vibrate,” says the research, published in the journal Nature, Ecology and Evolution.

Here is where it gets actually interesting: When these eggs have been reintroduced to the rest of their clutchmates, who had been busy developing in relative silence, it seems that they somehow transmitted the data — namely, that some sort of danger was near — to those that did not hear the warning calls.

“Overall, we discovered that exposure to alarm calls had strong programming effects on the development of embryos and that these effects had been transmitted among embryos belonging to the same experimental clutch,” the authors wrote. “Embryos confirmed delayed hatching within the exposed clutch group—together with both eggs that have been exposed to alarm calls and their unmanipulated clutch mate.”