Scientists have found that zebra finches sing a special song to their eggs when it’s hot outside.
Using a high-pitched chirp, mother birds sit on the eggs and communicate to unhatched chicks that the temperature’s rising — and warn them to slow down their growth, for a better chance at survival. Birds who sang the warning song produced up to six, smaller fledglings, while the rest produced fewer, larger chicks. Smaller fledglings may have an easier time shedding body heat, which could give them an advantage in hot weather.
This finding is remarkable for bird researchers studying development of babies before they hatch, and could help the birds adapt to climate change.
[H/T New Scientist]