Among the numerous representatives of the terrestrial vertebrate fauna, animals of two classes occupy a special place - amphibians (amphibians) and reptiles (reptiles). It is characteristic of both groups that the temperature of their bodies depends on the temperature of the environment - these animals are cold-blooded, and the possibilities of their settlement are determined primarily by climatic conditions.

Amphibians (Amphibia) are a unique group among all vertebrates: most species are part of both aquatic and terrestrial ecosystems throughout their life cycle. From this point of view, they are an intermediate group between completely aquatic vertebrates - fish - and the remaining terrestrial vertebrates - reptiles, birds and mammals.

Of the 6600 - 6800 species of reptiles on Earth, only a few dozen live in the temperate zone, and only a few penetrate into the northern part of it, in particular into the taiga complexes. This is achieved by a number of special devices. One of them is the ability to form glycerol from liver glycogen and thereby tolerate low temperatures during hibernation, inevitable at relatively high latitudes. One of the other ways of adaptation to existence in taiga complexes is the transition to ovoviviparity or viviparity, when embryos go through all stages of development in the egg membranes in the female’s body, since the development of eggs in the external environment requires fairly high temperatures. And finally, the third way is to use microenvironmental conditions, where average temperatures are usually higher than normal for the surrounding area.

From the order Squamata, two species of lizards and one species of snakes reliably live in the Khanty-Mansi Autonomous Okrug. The viviparous lizard (Lacerta vivipara) is one of the most widespread species of reptiles, but is associated primarily with the forest zone. However, the viviparous lizard penetrates far to the north, in some cases going beyond the Arctic Circle. In Western Siberia, this species reaches the Ob Bay.

Methods for studying amphibians in nature

Amphibians are one of the most important links in food chains in biocenoses, often playing a significant role in the nutrition of vertebrates and in regulating the number of invertebrates, both terrestrial and aquatic, as well as for measurements, carrying out trophic connections between land and fresh water bodies.

The inventory of amphibians begins with the study of the biotopes occupied by amphibians. The initial stage is familiarization with handwritten sources (diaries) and cartographic material. To do this, it is necessary to have a plan for the natural park and protected zone. Topographic plans that take into account the nature of the vegetation and relief of the area are especially useful. Acquaintance with biotopes in nature usually begins with a general description of vegetation. Plants serve as a food source for consumers of the first order - invertebrates - phytophages, on which amphibians feed. For a more detailed study, a geobotanical description is necessary, not necessarily in such detail as botanists do. But with coverage of background species of herbaceous vegetation. As well as species serving as indicators of certain forest types. The composition of the forest stand is described with an accuracy of 10% according to generally accepted methods, taking into account age, layering, density, and the degree of human use. Shrubby and herbaceous vegetation is also described. As for the soil, when studying amphibians, its mechanical composition is most important. The role of relief, especially in mountainous areas, is quite well known. On the plains, meso- and micro-relief is of great importance. Thus, the duration of the active period of life of amphibians and the nature of their activity depend on exposure. Elements of microrelief serve as a refuge from predators and unfavorable conditions. Reservoirs serve as spawning, port and wintering stations for amphibians. Humidity is measured using a psychrometer, while temperature is measured at the same time. Relative humidity is later calculated using special tables. Precipitation is measured using a rain gauge using the same method used by meteorologists. It is better to measure the soil temperature with a minimum and maximum thermometer. The most important for studying the activity of animals are the minimum and maximum temperatures, which can be recorded once a day, if necessary, more. It is necessary to protect thermometers from direct sunlight. For ongoing route observations, the most convenient thermometer for measurements on soil and water is a sling. First, the temperature is measured on the shore, then in the water or at the bottom, near the object of interest or directly in it. When taking measurements on land, you need to cover the thermometer ball from direct sunlight.

Animal inventory itself is a count, with or without catching and tagging. The most suitable methods for counting amphibians are: the route method, counting using trap fences and trap ditches.

The main requirements when conducting route surveys are the following: the route (or its individual parts) must pass within the same biotope; the length and especially the width of the route must correspond to the nature of the biotope; records should be carried out under the most favorable conditions and time of day.

The simplest way to count amphibians, requiring minimal preparatory work and time, is to count animals along the routes, or the transept method, the test tape method.

At the end and during the recording, the weather conditions are first noted. During the registration process, the following is recorded: the type of animal, if possible, its gender and age, behavior, and direction of movement are determined. If the number of amphibians is low, the time of each meeting can be noted. In summer, most amphibian surveys are carried out at dusk, when the activity of terrestrial species increases. At night and at dusk, migrations of aquatic amphibian species occur more often. At this time it is necessary to have a flashlight. However, it should be taken into account that animals often leave the line of light before they can be detected. Therefore, it is necessary to turn on the flashlight only when sounds are heard. Based on the literature data, the route method is best to take into account tailless amphibians.

Animal counting at trial sites is essentially a variant of route counting. To determine the absolute number of amphibians on the site, all animals encountered are caught, counted, and their species, sex, and age are determined. The route counting method is less suitable for amphibians with daily activity at night and is not suitable for secretive species.

To determine the full composition of amphibians living in a given biotope, trapping fences or trenches (grooves) are used. The rarely used method of counting amphibians using trapping pits was probably first used in our country by E.S. Ptushenko (1934). But, unfortunately, in our conditions we do not use this method due to the rugged and swampy floodplain of the river.

An analogue of the trap groove method is the trap fence method. Based on the data from trapping fences, one can judge phenological phenomena in a number of amphibian species, especially those living secretly. Catching with fences makes it possible to judge changes in the numbers of these species, their appearance or disappearance, and the replacement of some widespread species by others.

Routes laid out in combination with trapping fences in the main biotopes make it possible to relatively quickly identify the species composition of amphibians and their relative abundance, and with long-term use, clarify a number of ecological issues.

The study of the number of living organisms and its dynamics is one of the main problems of ecology. In nature reserves, one of the main tasks, after inventory, is monitoring population dynamics and identifying the factors determining its progress. The methodological manual on keeping a chronicle of nature only recommends conducting route surveys of amphibians. But this is certainly not enough. It is necessary to use data from trap fences, at least in the main biotopes, especially since these may be the same fences that are used to study small mammals. To study population dynamics, it is important, first of all, the uniformity of methods. In other words, the selected methods should not be replaced by others without special need, although they can be used in parallel. It is the uniformity of methods that minimizes the possibility of comparing results across time and space.

Monitoring of population dynamics can be carried out on permanent routes established in the main biotopes. Routes, especially at night, should be laid along roads, paths, clearings, taking into account the possibility of detecting moving animals. Individual sections of the route are marked with stakes with numbers on them, or numbers are painted on trees, flags attached to them, etc. The accountant, moving along the route, notes the place and time of each meeting, and the weather condition. A permanent route can pass through various biotopes, but it is desirable that the ratio of segments approximately corresponds to the specific gravity of each biotope in a given area.

Counting with the help of catch fences and ditches serves as a necessary complement to route counts. What is necessary here is, first of all, the uniformity of the chosen methods. It is better to go around fences and ditches in the morning. Analysis of catches can be carried out on site, but if additional data is required, the animals are placed in cloth bags and taken to the hospital. Processing is carried out depending on the tasks assigned. In this case, at a minimum, the weight, total length of the animal, sex, and age are determined. Recorders and maximum and minimum thermometers can operate at fences and ditches, the readings of which are recorded in the diary simultaneously with the catch data and transferred to the workbook.

Methods for studying reptiles in natural conditions

Methods for studying reptiles basically coincide with the methods proposed for amphibians.

When carrying out an inventory of reptiles, a card index is compiled. To do this, a card is created for each of the species found in the reserve, on which all the information is briefly transferred. These data are entered in more detail into a special journal where the results of one’s own research are also recorded. The most important component of further work is the mapping of all locations of individual species, both within the reserve and beyond. Further, for ease of use, the results obtained should be transferred to separate map diagrams.

The most important component of the program is carrying out work related to the study of numbers. As experience shows, the optimal selected transect width should not exceed 3 m with a length of 1 - 1.5 km for lizards and 5 - 6 km for snakes. The transect must be selected within one biotope, for example, along the edge of a forest, along a river bank. Taking into account the specifics of the seasonal and daily activity of reptiles, surveys should be carried out at different times of the year under optimal environmental conditions. In summer, in sunny weather, animals should be considered from 9 to 12 hours. If there are species with nocturnal and mixed activity, surveys are carried out even after sunset using a flashlight. The study of the dynamics of reptile populations, like many other animals, includes the determination of parameters such as growth, fertility, and mortality. As part of the work carried out in nature reserves, it is advisable to study life expectancy and natural mortality.

Only young individuals - young of the year - are marked, and not immediately, but 1-2 weeks after their birth, when the animals have grown somewhat. It is necessary to mark animals in 2 - 3 areas. In the future, at least twice a month, marked individuals are caught and changes in growth that have occurred during this time are noted in a notebook, where all animals are numbered. The procedure is repeated the following spring and then continues regularly for 2 to 3 years. The method described above allows us to identify age classes and accurately judge the age composition.

Until relatively recently, there was no reliable method for accurately determining the age composition of amphibian and reptile populations. The age structure was studied by constructing variation curves for body length and the weight of the eye lens. These methods make it possible to determine the age structure only very approximately; they require extensive material for statistical analysis and cannot give a specific idea of ​​the age of individual specimens. In 1969, a method for accurately determining age from stained bone sections was published, and then a number of confirmations and additions to this method. But this technique is completely inapplicable in field conditions, since it requires skills in working with a microscope and mastery of special painting techniques. According to E.M. For Smirnova, it is impossible to deform age up to three years; only from three years old can age be determined from bone sections. The general scheme for preparing the preparation is as follows: collecting material (femurs), fixing in formaldehyde, decalcifying to the point of flexibility, washing, cutting sections, staining, viewing under a microscope in glycerin, passing through alcohols and enclosing in balm.

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