When standing by their hole, marmots, like many other inhabitants of open spaces, inform their neighbours about the danger using the alarming acoustic signal. Sometimes they continue to cry even when they have left for their hole. At the same time, the sound timbre changes a lot in the hole. The present work studies for the first time one of the possible mechanisms which makes easier the propagation of the signal in the holes.

The idea of ecological inheritance as a specific mechanism of information transmission from one generation to another in the organic world belongs to outstanding biologist Prof. N.P. Naumov. Information in the signal field is encoded in stable elements, or traces of life activities left by many animal generations. In the aggregate, they form a matrix of stable elements, which is a material information carrier that governs the pattern of animal behavior in the space of biogeocenosis. As a result, every new generation follows (inherits) the trajectory of territory use by preceding generations, which is confirmed by observations on marked animals. The ability to distinguish from the background these stable elements carrying species-specific information and adequately respond to it is apparently inherited genetically, as is the ability of animals for learning and imitation. Ecological inheritance is based on the genetic inheritance of abilities: the ability to adequately respond to stable elements of the signal field.

The main propositions of the biological signaling field concept suggested by author of the concept N.P. Naumov and his followers are discussed in this review based on the example of mammals. It has been shown that the development of this concept over the last 30 years has been based on its fundamental proposition. The main idea is that, from generation to generation, mammals leave traces of their life activity at landscape objects in a biogeocenosis space and form a matrix of stable elements, i.e., a system of attractors, which are objects that attract attention from animals and their usage of a territory with all its resources. The stable elements establish a visual-olfactory image of the territory, which influences the trajectory of each new generation of mammals. It has been suggested that, as it is similar to biological productivity and species diversity, the field of biological signaling field has consistent stages of ecological succession. Although this concept has not become widespread, in recent years, studies based on its fundamental propositions have been published regularly. A necessary condition of the further successful development of the concept is the establishment of new research methods, including the simulation of the processes of the formation of a matrix of stable elements under experimental conditions.

In Eurasia, the areas of eight out of nine marmot species are completely or partly located within an epi-platformal orogeny area. Epi-platformal orogeny is the process of mountain building on the territory of smoothed relief, which proceeded in a platform mode for a long time. In Eurasia, the area of epi-platformal orogeny includes the Hindu Kush, Tan Shan, Pamir, Kunlun, Nan Shan, Qinling, Altai, and Sayan mountains; the Baikal region, Transbaikalia, and the Stanovoy Range. Formation of the contemporary epi-platformal areas started in the late Oligocene or later and continues till now. The concept of geographic speciation suggests that, at the platform (plain) stage of relief formation, building the geographic barriers was insufficient. First, this promoted panmixia and prevented the divergence of the founder population and; second, the formation of the Marmot genus area was accompanied by a relatively rapid and wide spread of marmots. In contrast, intense formation of geographic barriers in the active phase of orogeny weakened panmixia; division of the founder population into many sites led to genetic disintegration of the population.

The temperature regime of hibernation has been studied in six ground squirrel species from 13 geographic populations living beyond the permafrost zone. It is shown that hibernation usually takes place at low above-zero temperatures and that the least deep burrows are found in the zone of subzero monthly temperatures. Populations have been found that inhabit areas where monthly temperatures during the hibernation period fall below zero in almost the whole range of depths at which nest chambers are located.

Before hibernation, steppe marmots (Marmota bobak Muller 1776) close their burrows to prevent convection transfer of heat to the inside of the burrow. As a result, the temperature inside the burrow differs only slightly from that of the surrounding soil. Using data on soil temperature, I described the temperature regime of steppe marmot burrows (depth from 140 to 450 cm) during hibernation (from August to April), within the species and subspecies ranges. Taking into account the total soil depth of the hibernation chamber and the dates for the beginning and end of hibernation, the steppe marmot enters hibernation at a temperature of 8-16 °C, and ends hibernation at a temperature of 2-4 °C. The hibernation temperature regime differs significantly between the subspecies. M. b. bobak winters at a temperature of 3-4 °C higher than M. b. schaganensis. In the range of M. b. schaganensis marmots start hibernation 1 to 2 months earlier than in the range of M. b. bobak. The cause of subspecies differences in dates of onset of hibernation appear to lie in the zonal properties of seasonal changes in air temperature. In the course of hibernation, the soil temperature declines gradually at a rate approaching 1 °C per month.

Four key factors determining the ecological niche of the Himalayan marmot, Marmota himalayana Hodgson (1841), in the Central Himalayas (Nepal) have been identified. These are elevation above sea level, temperature, the presence of accumulative formations, and feeding conditions. The Himalayan marmot ecologically differs from all other marmots of the world fauna, and the main difference is that the lower boundary of its range lies very high—3000 m above sea level.

The ecological aspects of the concept of the biological signal field proposed by Naumov (1971) are discussed using the example of mammals. From the works published by Naumov, it might be assumed that the biological signal field is a specific and very powerful ecological factor that performs several functions. It organizes the spatial activity of animals, transmits information about the population spatial structure and the using of a territory over a number of generations, and organizes and supports the stability of the ecological system structure. While on the subject of the empirical importance of the problem, it is worth noting that the anthropogenous factors not only modify the substance–energy condition of the habitats but also change the biological signal field as an informational system. By destroying or deforming their signs, we deprive animals of the base information that allows them to use a territory with minimum temporal energetic costs. We also don’t know what the possible consequences of the human intervention in the information processes of animal populations are.

The study was based on long-term field observations of individually marked pikas. Data were collected from 1991 to 1993. Observations on the Altai pika were carried out in the Sajano-Shushenskii Biosphere Reserve (West Sajan, Russian Federation). The animals were live-trapped, sexed and marked with colored eartags. Average distance between the centres of activity of nearest neighbor male-female combinations was approximately three times less than distances separating male-male or female-female combinations. There is a supposition that formation of heterosexual couples permits more complete use of protective resources, while maintaining a certain (about 30m) distance from the centers of activity of nearest neighbors of the same sex. Adult males and females on the whole are territorially conservative. They are only inclined to shift their activity centres in late summer to early autumn. Two levels of activity centre shift are defined: (1) shift within an individual home range, of less than 15 m; and (2) moving to colonize a vacated neighbor range, over 20 m. In the latter case replacement of individual ranges is usually observed, i.e. the boundary of the former occupant. It is supposed that the territory of pika settlement serves its inhabitants as an information matrix. Pattern of territory use by animals results from interpreting information, kept in the form of landscape specificity and traces of vital activity of previous generations. In late summer, activity patterns and area of individual range begins to decrease, and individual and sex differences are minimized. The area of individual home ranges of adult males and females are inversely correlated with the density of the population. But in the case of males, the correlation is higher than for females.

Marmots are a life form (or ecotype), characterized by diurnal activity, high population density and dwelling in open landscapes. The key behavioral component of this life form is the timely warning of neighbors about the danger by means of a sound signal. Among ecological determined factors, I distinguish selection for the specialization of vocal activity of marmots, selection for optimization of the rhythmic structure of signal and selection for increasing the noise immunity of the transmitted message. Among the genetically determined factors, I distinguish the process of speciation, geographical variability, and gene drift in small isolated populations and variability in joint settlements of different species of marmots. The role of the landscape is so great that it even affects the rhythmical structure of the alarm call. The rhythmical structure of the signal is controlled by a vertical dismemberment of the relief of the terrain populated by marmots. The alarm call is designed not only for the animals outside of the burrow but also for those in the burrow. Similar to tubes, burrows have radial resonance. Judging from their diameter marmot burrows suppress the frequencies higher than 1 kHz but amplifies the lower frequencies. In order to increase noise immunity in the burrows the marmot alarm call has the low frequency component and an amplitude modulation. All the marmot species are characterized by species-specificity of structure of the alarm call. The genetically-determined species specificity of the signal structure encodes the population genotype. As a result; different species encode the same function using different symbols.

To study the early stages of wolf domestication, we investigated the remains of large canids from the Yana site. Morphologically they cannot be called dogs, but there are certain indicators of the wolves' relationship with people, favorable to the start of domestication. The sample is dominated by animals with worn, partially missing teeth and various bone pathologies. Often these animals are medium-sized. One skull of a nearly adult individual demonstrates juvenile characteristics. The morphologic and morphometric anomalies observed can be explained by commensalism (deficient and young animals using the resources of human settlement as an alternative food source). On the other hand, pathologies could have been an indirect result of commensalism, rather than its cause. Due to the risk of conflict with humans, only the most tolerant animals could live near their settlement. Experiments with living animals show, that tolerance comes at the cost of accumulating morphologic pathologies, genetically associated with tolerance, which was observed in many Yana wolves. High sociality and vocal behavior allowed wolves to approach human settlements, becoming some of the earliest domesticated animals. The site yielded evidence of a special attitude towards wolves, perhaps indicating a totemic cult. The Yana site material, interpreted in light of the biological characteristics of wolves, demonstrates for the first time the earliest stages of domestication, which can be characterized as self-domestication.

The drawing of netherlandish painter Pieter Bruegel the Elder "The Big Fish Eat the Little Fish" reflects perhaps not political allusions, as it is interpreted in the history of art, but a graphic food-chains scheme. It is possible that the picture engraving, stored in the British Museum, has influenced the creation of the food-chains concept by British ecologists Johnstone (1908), Hardy (1924) and Elton (1927). The taxonomic attachment of organisms depicted in the drawing has been determined.

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 2 = 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 2 = 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.

All the diversity of sound signals by mammals is subordinated two basic functions: function implementation of the populations of genotype and function realization of the ecological niche of species populations. The basic functions have resulted from some relatively independent trends in the evolution of sound signals as those developing the genetically determined structure and the ecologically determined functions. A relative independence of the above trends in the sound signal evolution supports variation.