Mother birds communicate with their developing chicks before they even hatch by leaving them messages in the egg, new research by a team from the Department of Zoology, University of Cambridge, has found.
By changing conditions within the egg, canary mothers leave a message for their developing chicks about the life they will face after birth. In response, nestlings adjust the development of their begging behaviour.
If chicks get a message that they will be reared by generous parents then they beg more vigorously for food after hatching. But chicks that are destined to be raised by meaner parents end up being much less demanding.
By attending to messages in the egg, nestlings gain weight more rapidly because they match their demands to the parents’ supply of food, and can avoid either begging too little or wasting effort on unrewarded begging.