Destruction of Sound Signal Structure in a Peripheral Population (as Exemplified by the Gray Marmot Marmota baibacina).

The variability of the alarm call of the gray marmot (Marmota baibacina) in the peripheral population in the valley of the Arpa River (Kyrgyzstan) is described. It was earlier reported that this population lived together with the red marmot (M. caudata).

Sex Accent and Biphonation in the Sound Signal of Ground Squirrels (Mammalia, Rodentia).

The alarm call of the little ground squirrel (Spermophilus pygmaeus), like those of six other Eurasian ground squirrels, contains a high-frequency component. In males, the peak and maximum frequencies of the high-frequency component are higher than in females. Biphonation of the alarm calls of Sp.

Two models of the sound-signal frequency dependence on the animal body size as exemplified by the ground squirrels of Eurasia (mammalia, rodentia).

Dependence of the sound-signal frequency on the animal body length was studied in 14 ground squirrel species (genus Spermophilus) of Eurasia. Regression analysis of the total sample yielded a low determination coefficient (R = 26%), because the total sample proved to be heterogeneous in terms of signal frequency within the dimension classes of animals. When the total sample was divided into two groups according to signal frequency, two statistically significant models (regression equations) were obtained in which signal frequency depended on the body size at high determination coefficients (R = 73 and 94% versus 26% for the total sample).