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). The authors did not find the red marmot there. Two forms of aberrations were found in the edge population of the gray marmot: amplitude modulation and no pause between the components. The destruction of the signal structure that is typical of the species is probably associated with the disruption of gene flow and does not contain clear signs of hybridization. The material was collected under the field conditions.

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. pygmaeus, Sp. musicus, Sp. xanthoprymnus, and Sp. alaschanicus has been demonstrated, with the low- and high-frequency components generated by different sources in the vocal tract. The material was collected in the field.

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 (R2 = 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 (R2 = 73 and 94% versus 26% for the total sample). Thus, the problem of correlation between animal body size and the frequency of their vocal signals does not have a unique solution.

[Amplitude modulation in sound signals by mammals].

Periodic variations in amplitude of a signal, or amplitude modulation (AM), affect the structure of communicative messages spectrum. Within the spectrum of AM-signals, side frequencies are formed both above and below the carrier frequency that is subjected to modulation. In case of harmonic signal structure they are presented near fundamental frequency as well as near harmonics. Thus, AM may by viewed as a relatively simple mechanism for controlling the spectrum of messages transmitted by mammals. Examples of AM affecting the spectrum structure of functionally different sound signals are discussed as applied to representatives of four orders of mammals: rodents (Reodentia), duplicidentates (Lagomorpha), pinnipeds (Pinnipedia), and paridigitates (Artiodactia). For the first time, the classification of AM in animals' sound signals is given. Five forms of AM are picked out in sound signals by mammals: absence of AM, continuous AM, fragmented, heterogeneous, and multilevel one. AM presence/absence is related neither with belonging to any specific order nor with some particular function of a signal. Similar forms of AM can occur in different orders of mammals in parallel. On the contrary, different forms of AM can be detected in signals meant for similar functions. The assumption is made about AM-signals facilitating information encoding and jamprotection of messages transmitted by mammals. Preliminry analysis indicates that hard-driving amplitude modulation is incompatible with hard-driving frequency modulation.

[Biological signaling field in mammals (towards 110th anniversary of professor N.P. Naumov)].

Last 30 years the concept of biological signaling field, proposed by N.P. Naumov, developed, by and large, on the base of its main proposition according to which mammals leave on the landscape objects within a biogeocenosis some traces of their life activity forming, from generation to generation, the so called "matrix of stable elements" (Naumov, Goltzman et al., 1987). This matrix of stable elements is, really, a system of attractors. Within the context of signaling field, attractors are objects that attract animals' attention (Goltzman, Kruchenkova, 1999) and organize their usage of territory with all the resources that could be found on this territory. Elements of landscape attracting animals' attention form a system of attractors of the first order (basic attractors) (Nikol'skii, 2011). In perspective, as the signaling field develops, it is exactly them that form the basis of the matrix of stable elements which the system of unstable elements would be attached to. With regard to attractors of the first order, traces of mammals' life activity can be treated as attractors of the second order. Animals do not mark the resources themselves, but only the territory where those resources are located. Stable elements produce an olfactory-optic image of the territory that is used by every new generation of mammals. A supposition is brought forward that, similar to biological productivity and species diversity, stable elements of signaling field are indicative of respective stages of an ecological succession. The matrix of stable elements is most steady in mature, climax communities. As an example, main runs that are used by many mammal species can be considered. Last years, publications appear regularly in which main propositions of the signaling field concept are applied. A necessary condition for further development of the concept seems to be the establishment of new exploratory methods including modeling of processes that lead to the matrix of stable elements formation.

[The parallelisms in of sound signal of domestic sheep and Northern fur seals].

The parallelisms in communicative behavior of domestic sheep and Northern fur seals within a herd are accompanied by parallelisms in parameters of sound signal, the calling scream. This signal ensures ties between babies and their mothers at a long distance. The basis of parallelisms is formed by amplitude modulation at two levels: the one being a direct amplitude modulation of the carrier frequency and the other--modulation of the carrier frequency oscillation. Parallelisms in the signal oscillatory process result in corresponding parallelisms in the structure of its frequency spectrum.

[Spatial distribution of Marmota baibacina and M. sibirica (Marmota, Sciuridae, Rodentia) in a zone of sympatry in Mongolian Altai: bioacoustic analysis].

The spatial distribution of two marmot species Marmota baibacina and M. sibirica in a zone of coexistence was studied by using their alarm call as a diagnostic trait. It was found that M. baibacina prefers to inhabit bouldery screes, whereas M. sibirica inhabits all suitable biotopes. The difference in biotopic distribution of these species could be explained by M. sibirica forcing M. baibacina out of optimum habitats. Cases of coexistence of both species in one family group sites were registered, which might contribute to the appearance of hybrids.

[Aberrations of the alarm call of the steppe marmot, Marmota bobak (Rodentia, Sciuridae)].

Aberrations, or deviations from the normal type of alarm call have been studied in the steppe marmot. One regular and several rare aberrations have been identified. The regular aberration manifests itself in all six populations studied, from the Kharkov Region in the west to the eastern border of the Orenburg Region in the east, with its frequency in the populations varying in different years from 10 to 66%. Rare aberrations occur sporadically and not in all populations.

[The influence of amplitude modulation on the structure of call spectrum in marmots (Marmota, rodentia, sciuridae)].

A relationship was established between the amplitude modulation and the structure of call spectrum in animals by the example of alarm call in three marmots (Marmota sibirica, M. menzbieri, and M. caudata). In the case of amplitude modulation, side frequencies are produced higher and lower than the carrier frequencies. In the absence of amplitude modulation, no side frequencies are produced.