It sounds like one of those mysterious, inexplicable things that animals do, but two researchers from the University of Vigo in Spain have established a very specific pattern of behavior and found that it changes the direction of bird development.
The researchers studied 90 gull eggs with yellow legs that were subdivided into "clutches". This is a term for all eggs in a nest. They separated a couple of eggs in a clutch and played adult seagull warnings. As a result, the eggs began to move.
"Seagull embryos change their motility when exposed to adult-triggered alarms, causing the egg to vibrate," states the study, published in the journal Nature, Ecology and Evolution Bleats of each other, Study Results " src-mini = "// cdn.cnn.com/cnnnext/dam/assets/1
Here it becomes really interesting: When these eggs were returned to the rest of their lover that developed in relative silence, the information – that some kind of danger was in the vicinity – somehow seemed to have passed on to those who did not hear the warning calls.
This knowledge transfer was evident in the development of the coupling mates. Clutches where no members were exposed to alerts developed differently than entire clutches, where some members were exposed to the calls.
We found that exposure to alarms has strong program implications for the development of embryos and that these effects are transferred to embryos that belong to the same experimental coupling, "the authors wrote." Embryos showed delayed slippage in the embryo exposed clutch group – including the two eggs that were exposed to alarm calls and their unmanipulated clutch partner. "
The effects continued after birth The warning vibrations of a non-hatched bird would hit the non-hatched siblings, as they did All are completely vulnerable and can not protect themselves when in danger The researchers found that this communication changed the evolution of the birds and their behavior after hatching.
Chicks from the exposed clutches "squatted after listening to alarm calls from adults faster than chicks from the control group, regardless of whether they were manipulated or not. "
This means that more risk-conscious eggs could be better prepared after birth.
It makes sense that baby birds can hear the danger and react to it while they are still developing in the egg, just like humans Babies can perceive and respond to sounds in the uterus. However, the way it affects their development and behavior is a fascinating limit. The researchers say the next step is to see if different environmental stimuli promote different changes in developing birds.