Parent-offspring Communication

Marty and Andy are principally interested in how parent birds and their young communicate. For example, nestling birds, like lots of animals, produce vigorous begging displays that include stretching, wing flapping, and loud calls that can reach 70 - 80 decibels. The intensity of these signals is puzzling because parents and young are usually close to one another, so a loud, vigorous signal seems unnecessary. Perhaps more importantly, these signals may also take some energy to produce and seem to make nests more obvious to predators. Thus, we have been trying to understand why these conspicuous begging signals might have evolved.