Science

Animal children listen to their parents even before they are born

Karen Hopkin: Sound can convey a lot of information. They can warn animals of potential dangers …,

[CLIP: Colobus monkeys vocalize]

… let your parents know when your offspring are hungry …

[CLIP: Baby lamb bleats]

… or act as a copulation call, a territorial warning, or a means to inform others in the area that you are there.

[CLIP: Wolves in chorus]

And it turns out that even embryos pay attention to this natural soundscape. More and more studies have shown that for many animal species, embryos use sounds from the environment to induce development. This is a trick that can give you benefits after you are born.

Millen Mariette: In the zebra finch seed I’m studying, I’ve found that my parents make special phone calls when it’s hot. And those fever calls prepare for embryonic development for fever.

Hopkin: Millen Mariette Of Deakin University, Australia. She happened to make this discovery.

Mariet: While examining the communication between parents in the nest, I noticed that when parents hatch their eggs themselves, they may make a completely different cry than others.

[CLIP: Zebra finch heat call]

Hopkin: And since there was no one around, she wondered if her parents were talking to the eggs. So she hung around the aviary and listened.

Mariet: So it soon became clear that my parents were only calling eggs when it was really hot.

Hopkin: But what did it do to the developing chick?

To find out, Mariette began borrowing eggs. She took them to the incubator and played either a zebra finch heat call or another call made by her parents when she changed shifts. Then she will return them to their nest.

When the chicks hatched, Mariette noticed that the birds that heard the heat were actually smaller than the other birds.

Mariet: It was a little surprising at the time, but as adults grow more babies, it turns out that it is advantageous to control their growth in the heat. And that’s probably because they avoided growing costs in the heat, which requires a lot of energy.

Hopkin: And birds are not the only ones to learn about the general condition through embryo eavesdropping.

Mariet: Frog embryos recognize that snake predators need to take advantage of the vibrations that occur as they approach eggs to hatch and avoid eating in order to fall into the water.

Hopkin: And the cricket embryo pays attention to the male courtship song.

[CLIP: Crickets chirping]

If it sounds like there are a lot of men available …

[CLIP: Denser audio of cricket sounds]

… females speed up growth to take advantage of the situation, while males take longer, so they are stronger and bigger when they finally appear.

Some embryos communicate with their siblings to coordinate the time of hatching so that no one is left behind. The baby crocodile then talks to her mother from inside the egg.

[CLIP: Nile crocodile embryos]

Mariet: The call emitted by the embryo also tells that the mother is about to hatch so that she can begin digging the nest. This makes the hatching process for all embryos in the clutch much easier.

Hopkin: Of course, the next question would be:How all of these embryos actually listen through the shell and uterus And More importantly action About what they heard?

Mariet: I had to go into neurobiology and see how the brain processes this information and how it is transmitted to developmental changes.

Hopkin: And Mariette discovered that in these species, the areas of the brain that process sound are connected to areas that control hormone production and more. She explains in the journal. Ecology & Evolution Trends.. [Mylene M. Mariette et al., Acoustic developmental programming: a mechanistic and evolutionary framework]

Mariet: Therefore, the embryo can react to the sound without actually knowing what the sound is. Therefore, the embryo cannot consciously hear those sounds. Basically, it’s just a spontaneous physiological response.

Hopkin: But it helps them make sound decisions that signal them for future success.

[The above text is a transcript of this podcast.]

https://www.scientificamerican.com/podcast/episode/animal-kids-listen-to-their-parents-even-before-birth/ Animal children listen to their parents even before they are born

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