Bird embryos sense external alarms and transmit signals

BEIJING, July 24 (Xinhua Zhang Mengran) According to a study published online on the 23rd in the British journal Nature Ecology and Evolution, embryos in bird eggs can sense the sound of alarms from adult birds and transmit this information to other birds in the same nest by vibration. This information will help the developing embryos adapt to the external environment after incubation.
many animal embryos receive information from both parents through hormones or sound signals that help set the embryo's development so that it can better adapt to the postparto environment. For egg animals that develop within the egg, the egg communicates their level of development through vibration, allowing siblings in the same nest to hatch at the same time. Previously, however, scientists did not know whether eggs could perceive external environmental information and transmit it in their nests.
This time, scientists Jose Nokira and Alberto Valendo of the University of Vigo in Spain divided the eggs of yellow-legged gulls into three nests, recorded the predation alarms of adult birds on some nest eggs, and left others soundproofed. In nest eggs that played adult bird alarms, the researchers recorded only two of them to see if the alarm calls affected embryonic development and whether the information could be passed on to the third egg.
team found that eggs that played alarm calls vibrated more, made fewer sounds, and hatched more slowly than control groups in soundproofed environments. After successful hatching, chicks who heard the alarm call in their eggs had higher levels of stress-related hormones and quickly curled up when they heard the alarm call. The scientists also found that the third egg in the same nest as the bird's egg, which had heard the alarm call, also had higher levels of stress-related hormones after hatching into chicks, and showed the behavior of the siblings, suggesting that the vibration of the same nest egg was the source of this information.