The research team from the Institute of Dickin, Australia found out that some species of birds can sing their non-hatched chicks.
They installed microphones next to the nests of 125 zebra amadines. As it turned out, besides the usual sets of sounds, when the birds remained near their nests alone, they sang a special melody, distinguished from all others. And this happened only in hot weather. The impression was created that the birds thus talked with their own chicks yet.
Interested in unexpected results, the researchers recorded this unusual melody and took the group of Zebra Amadin eggs into the incubator. Then half they turned on the record of the unusual melody, after which they were distributed in the nests, both in the warm environment and in the cold. Interestingly, the hatched chicks, which were given to listen to the melody, eventually weighed less than chicks from other "warm nests", which record the melody of adult amadines did not turn on. But the most amazing thing that in the future those young, listened to "instructions" of their parents and grew up in "warm nests", were able to have more chicks compared to the rest of the relatives for which the record was not included.
How the melody changes the development of the fetus inside the egg at the moment is incomprehensible. Probably a certain sound makes changing the hormonal composition inside the fetus, but this theory needs an additional study.
In any case, in the light of the increasing temperature on the planet, this skill will help zebral amandes adapt to the surrounding conditions, which cannot but rejoice.