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Скачать бесплатно! Научная работа на тему BISONS FROM MESHCHERA. Аудитория: ученые, педагоги, деятели науки, работники образования, студенты (18-50). Minsk, Belarus. Research paper. Agreement.

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Опубликовано в библиотеке: 2018-09-09

by Marina KOLOTOVA, laboratory staff researcher, Oksky Biospheric State Preserve

Bisons were among the very first endangered species to be entered into the Red Data Book of the International Union for the Protection of Nature and Natural Resources. By the time when the threat of their complete extinction was recognized both by experts and the public at large (1924), the genofond of this particular species was nearly exhausted. According to official records the number of bisons still capable of effective reproduction in 1918-1919 was reduced to a really critical number of 12. As for Russia, efforts for the restoration of the bisons population were commenced as early as 1946, and on December 20, 1959, the federal authorities adopted a formal decision on the establishment of a special nursery at the Oksky Wildlife Preserve. Over the years it has emerged not only as a popular tourist and educational attraction, but a leading center of research whose experts are studying ways of replenishing the population of these ancient dwellers of European forests.

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Within the borders of this country, at the start of the 20th century, bisons were represented by two subspecies - the Caucasian and the European. And both were practically wiped out within a span of 15 to 20 years. According to the available statistics, the Belovezhskaya Pushcha Wildlife Preserve (Byelorussia) had a herd of 727 bisons which were practically all wiped out within a matter of one year with the remaining few animals perishing in 1918. In the Caucasus in 1910, the bisons population was estimated at 500-600 animals. By 1924 this number dwindled down to 10 or 15 and three years later what was left of the original herd perished in an epidemic. By 1926 the total number of bisons left in the public zoos and private stables in 15 countries was estimated at only 56. Many of these "survivors" were old or sick and by 1927 the species dwindled down to 48.

The causes of this catastrophe were several, including the felling of virgin forests, epidemics of foot-and-mouth disease and malignant anthrax, and unrestricted hunting sprees especially during World War I and the Russian Civil War (1914-1922).

So that was roughly the situation before the establishment of the Oksky Wildlife Preserve in this country Today it occupies an area of 202 hectares with its "residents" being kept in large pens, or enclosures, where the animals feel as unrestrained as out in the wild.

The person who stood at the "cradle" of the project was a woman - Senior Researcher Ye. Kiseleva. Over a period of 40 years she supervised a small, and predominantly male, staff and did a lot in order to promote a rapid growth of the herd in her charge and the spread of the endangered animals across the territory of this country.

Since 1999 the post of the director of the Preserve has been occupied by yet another lady-scientist-Senior Researcher Ye. Tsibizova. Today members of the staff focus their attention on stock-taking, organizing research expedition into promising areas of habitation of bisons and studies of herds' behavior and adaptation in different local environments. A total of 10 such expeditions have been mounted so far mainly into various areas of the Caucasus, Ukraine, Moldova, Byelarus and also Russia.

During the years of its existence scientists of the Preserve have completed a "menu" of plants consumed by the animals, determined the chemical composition of such fodders, studied the productivity of animals kept in pens and assessed the "impact" of bisons on the local forests and vegetation in general. Our veterinarians have kept records of 647 animal disorders, including 18 cases of helminthiasis (infestations with and diseases caused by parasitic worms). They have developed and introduced a range of preventive and curative measures which have produced the desirable positive effect: as compared with 1979,

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when a single animal could be infected with 13 kinds of helminths and an average of 643 parasites, by 1986 these numbers were brought down to 4 and 231 respectively.

The collected craniological* data have made it possible for our experts to conduct a comparative morphological study of the skulls of what we call the mountain hybrids, or crosses and thoroughbred Caucasian-Belovezhye bisons, assess the degree of their identity with the original species and the variations which have originated in the process of stock restoration. We have also determined the optimal breeding season and ways of age assessment of the animals.

Our specialists have also studied the reproductive cycle of our bisons, assessed the currently used breeding methods and mapped out improvements for the future. We have also conducted this country's first experiments with immobilization of animals (by means of drug injections) for purposes of their tagging, or labelling, and for veterinary treatment. In all, we have immobilized 32 and tagged 43 bisons. Our specialists have tried out various labelling methods, including those with liquid nitrogen (18 animals), alcohol solutions of fuchsin (7) and picric acid of different color (4). Today the "population" of the Oksky Preserve includes 10 calves (under 3 years of age) and 16 adult bisons (over 3 years old) including 13 females and 3 males.

But do what we can, the plight of the preserve is getting worse with every passing year so that now we are facing a real threat of degradation and extinction of our flock. The young calves become smaller in size, less resistant to adverse conditions and the birth-rate is dwindling. As compared with the 1970s when the birth-rate was 8 to 10 a year, today it is only 3 to 5; last year, for example, only two calves were born. And the situation is very much the same in other nurseries. According to the all-Russia census of bisons as of January 1,1996, the total population of the species here dropped by 37.8 percent since 1992. And prior to that we observed a stable annual growth of the all-Russia herd of 5 to 10 percent.

The main causes of the current plight include: direct extermination of bisons in the Caucasus during the tragic current events in Chechnya, Ingushetia and North-Ossetia; degeneration of small local herds of these animals in the central areas of European Russia due to a number of reasons, including dropping birthrates in nurseries, a sharp drop of the numbers of males, etc. And the latest signs of degradation appear to be linked with prolonged utilization of one and the

* Craniology - science dealing with variations in size, shape and proportions of skulls of humans and animals. - Ed.

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same territory which leads to an exhaustion of what we call the fodder reserves of pens and corrals, excessive contamination with helminths and other pathogens. And in the nursery conditions the principle of natural selection does not come into play.

In accordance with a Federal Program work was started in 1996 on the establishment of an unattended, or "wild-like" herd of bisons in European Russia (Bryansk, Kaluga and Orel regions). In keeping with this program some of the animals from the Oksky Preserve have been moved to the Bryansky Les preserve and the Orlovskoye Polesye National Park.

Since the preserve was founded a total of 317 calves were bom there and 198 of them have been sent to various "free-breeding" farms and zoos. The size of the "world flock" today exceeds 3,200 bisons with 1,500 of them being in Russia and other CIS countries, which represents a nearly 10-fold increase. 19 free- breeding stations have been set up with more than one third of the initial herd being former "dwellers" of the Oksky Preserve. Our "natives" can also be found in nine zoos in this and other countries and they can be easily identified by a prefix "Me" attached to their names (meaning Meshchera). In recent years a shortage of "fresh blood" began to manifest itself (inbreeding of closely related stock).

But now there seems to be a chance to remedy the situation with some of the European zoos providing to us young livestock free of charge. These new arrivals are placed into quarantine at the nursery of the Oksky Preserve. Brought there from 1999 to 2001 have been 40 bisons from Finland, Germany, Switzerland, the Netherlands and Belgium and then 30 of them were sent to the Orlovskoye Polesye and Bryansky Les preserves with the remainder being shared (for breeding purposes) between ourselves and the Prioksky Terrasny Preserve with which we maintain close cooperation. The "newcomers" have not yet reached the reproductive age and specialists pin great hopes upon them for "rejuvenating" our own flock and the "free-breeding" herds.

What one would like to say in conclusion is that some really radical improvements in the plight of Russia's bison herd can be achieved only by forming sufficiently large herds of animals in areas with favorable biological conditions wherein bisons would be able to breed and multiply into herds of several hundreds. And steps should be taken to prevent the establishment of small and isolated groups of these animals. And within the confines of the territories of habitation of these future herds conditions should be provided for what we call the genetic diversity of animals which would provide the basis for bigger and healthier bisons of the future.

Комментируем публикацию: BISONS FROM MESHCHERA

© M. KOLOTOVA • Публикатор (): БЦБ LIBRARY.BY

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