Parallelism in the sound signals of domestic sheep and northern fur seals

Parallelisms in the communicative behavior of domestic sheep and northern fur seals within a herd are accompanied by parallelisms in the parameters of the sound signal (the screaming call), which ensures the tie between cubs and their mothers at a long distance. The basis of parallelisms is formed by amplitude modulation (AM) of two levels: AM of the carrier frequency and AM of the oscillation modulating the carrier frequency. Parallelisms in the oscillatory process of the signal lead to corresponding parallelisms in the structure of its frequency spectrum.