This is Scientific Americans 60-Second Science. I'm Karen Hopkins.

Sounds can convey a lot of information. They can alert animals to potential danger, let

parents know when they're offspring or hungry, or serve as mating calls, territorial warnings,

or just a way to let others in the area know that you're there.

And it turns out that even embryos pay attention to this natural soundscape. A growing body

of research shows that for many animal species, embryos use audio from their environment

to guide their development, a trick that can give them an advantage after they're born.

So in the species that I study, Susébera Finch, we found that the parents make a special

call when it's hot, and that those HIKO prepare the development of the embryos for heat.

Mielen Marriott of Deacon University in Australia, she made this discovery by chance.

I was studying the communication between the parents at the nest, when I noticed that sometimes

when a parent was intubating the eggs by itself, it was producing a call that was quite

different to the others. And since there was no one else around,

she wondered whether that parent might be talking to the eggs, so she hung around the

aviary and listened in. It soon became apparent that parents were only

calling to the eggs when it was really hot.

What did that do for the developing chicks? To find out, Marriott started borrowing the eggs.

She'd take them to an incubator and play them either the zebrafinch heat call or a different call,

one that the parents make when they change shifts. Then she'd return the eggs to their nests.

When the chicks hatched, Marriott found that the birds that had heard about the heat

were actually smaller than the others.

There was a little bit surprising at the time, but we then found that reducing

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