Zebra finches have been found to make a specific high pitch call in very warm environments when their eggs are in the final stages of incubation. 

Mylene Mariette, an ecologist at Deakin University in Waurn Ponds, Australia, conducted a study to analyze the importance of this call and the resulting effects on the finch embryos. In the study, recently published in Science, Mariette reported that this call is made when the outside temperature becomes dangerously hot and rises past 79 degrees. Both female and male finches have been recorded emitting the call. Scientists have concluded that this high pitch call allows for birds to communicate to their embryos that the outside weather is reaching extreme conditions. In another report in Science, Virginia Morell said that the developing chicks seem to understand this call and develop physical attributes that may help them to survive in the outside environment. 

To study this newly discovered call, Mariette placed 166 finch eggs at a standard temperature of 99 degrees. Toward the end of the incubation process, a recording of the shrill finch call was played to half of the eggs, while the remaining eggs acted as a control group. Upon hatching, the embryos exposed to the call were, on average, much smaller than those that were not exposed to the call. A smaller body size may be considered an advantage for the chicks because it allows for quicker heat loss.  Subsequently, the smaller chicks were shown to produce more eggs in the first mating season than the control chicks. This is the first time that scientists have been able to show that animals are using sound to change the physical development of embryos. 

This phenomenon has caused scientists to suggest that certain species may have dealt with rapidly rising temperatures before and therefore have a natural instinct to produce the call. It’s possible that certain species are more resilient to weather change than we have recently thought. Zebra finches, and other animal species, may not be as impacted by climate change as we have suspected, and they may be adapting to this new climate at a rate even faster than humans. As temperatures rise here in Clemson, hopefully our native birds on campus will prepare their eggs for the rising summer heat.