Дата публикации: 30 августа 2021
Автор(ы): Vyacheslav ROZHNOV →
Публикатор: Научная библиотека Порталус
Рубрика: БИОЛОГИЯ →
Источник: (c) Science in Russia, №5, 2010, C.20-26 →
Номер публикации: №1630325579
Vyacheslav ROZHNOV, (c)
by Vyacheslav ROZHNOV, Dr. Sc. (Biol.), Severtsov Institute of Problems of Ecology and Evolution, RAS
In 2010 an international forum devoted to the fate of the Amur tiger will be held in St. Petersburg. The viable population of one of the biggest cats on the planet is preserved only in the south of the Russian Far East, and approximately two dozens of this species are found in China. Today the Chinese proverb "People are careful of tigers, and tigers are careful of people" should acquire a new meaning, i.e. the only possibility to save these unique animals is to live in harmony with them. This is the main idea of a new "Strategy of preservation the Amur tiger in Russia", worked out by national scientists. Vyacheslav Rozhnov, Deputy Director of the Severtsov Institute of Problems of Ecology and Evolution, Dr. Sc. (Biol.) told about the research results, which formed the basis of the said document, to our correspondent Yevgeniya Sidorova.
—Of course, the tiger needs no special presentation, but probably the Amur subspecies has its distinctive features. Could you tell me about them ?
—The Amur or Ussuri tiger (Panthera tigris altaica) is one of the biggest on the planet, the body length of a male tiger reaches 220 cm and that of a tigress is 182 cm, its maximum weight is 250 kg (only the Bengal tiger competes with it in sizes). This splendid animal has a thick and long pelage, which provides reliable protection from winter frost. Though its ancestors came from a
tropical zone of Asia, and then gradually migrated to the north, forming an endemic subspecies of our country today. The tiger lives in cedar broad-leaved and oak forests of Sikhote Alin*, where wild boars, Manchurian wapiti and axis deer are prevalent and form the basis of its food supply. Due to a low population density of hoofed mammals, the size of the area used by the Amur beast is larger than that of its congeners.
—It is obvious that in order to protect the Amur tiger, specialists have to know not only its distribution area, but also have information, how its habitat is changing, whether it has enough food or competes for it with other beasts or even man. Do scientists possess now exhaustive information to answer such questions?
—National specialists carried out thorough studies of the Amur tiger. First attempts to register its number on the territory of Primorski Krai were made in the 1930s by Lev Kaplanov, Cand. Sc. (Biol.), and today Lazovsky State Reserve bears his name. At that time this talented and tireless researcher obtained a valuable material for biology of species. In the 1970s detailed data on the Amur tiger ecology were collected by the researchers of the Biology and Soil Institute of the Far-Eastern Scientific Center of the USSR Academy of Sciences (today RAS BS1 FEB) Anatoly Yudakov and Igor Nikolayev. The great contribution to formation of modern ideas on this striped beast was made by Yevgeny Smirnov, Cand. Sc. (Biol.) from the Sikhote Alin Biosphere Reserve named after K. Abramov, Dmitry Pikunov, Dr. Sc. (Biol.) from the Pacific Institute of Geography of RAS FEB, Yuri Dunishenko from the All-Russia Research Institute of Game Husbandry and Animal Breeding for Furs (Khabarovsk), Viktor Yudin, Cand. Sc. (Biol.) from RAS BSI FEB, Yevgeny Matyu-shkin, Cand. Sc. (Biol.) from Moscow State University, etc. Unfortunately, many of them are no longer alive. Their work is a foundation, which serves as a new Strategy of the Amur tiger preservation.
However, we have developed new modern approaches, which enable us to get information unavailable before.
* See: V. Kostenko, "For the Sake of the Wildlife Preservation", Science in Russia, No. 1, 2007. -Ed.
Russian zoologists traditionally studied biology of beasts in the taiga by their winter footprints—the so-called survey method, which is possible due to a stable snow cover. But this work is not safe, as a pathfinder has to move alone, otherwise he can startle a beast, not always in a mood for meeting man. Confrontations with poachers, which are also a usual thing, sometimes ended in a death of researchers. But in early 2000, the American scientists, who worked in the Sikhote Alin Reserve, were the first to use radiocollars. Due to expensive and rather labor-intensive method, our ideas on beast movements, time of its rest, etc. have become more accurate.
On February 29, 2008, on the basis of our institute and in line with an order of RAS President, Academician Yuri Osipov, was established "A permanent expedition of the RAS to study animals in the Red Data Book of the Russian Federation and other valuable animals of Russian fauna", Academician Dmitry Pavlov was appointed its manager and me—its head. On August 15, 2008, my colleagues and me started research under the project "A Study Program of the Amur Tiger in the Russian Far East". It is financed by the Konstantinovsky international charity foundation, Transneft company, and OAO Tekhsnabexport. Today we dispose not only of radiocollars but also satellite ones capable of providing all information on movements of marked animals in an automatic mode during a year. With the aid of a GPS receiver in the collar, we receive data on whereabouts of the beast and follow its route via the Franco-American satellite system ARGOS. This trend of studies is headed by the research assistant of our institute Jose Hernandes-Blanco, Cand. Sc. (Biol.).
—Obviously it is difficult to provide collars for all animals in the survey area, isn't it?
—Certainly it is not easy, as cats are highly intellectual creatures. It is very difficult to track down and outwit them but it is still possible. We have special leg-gripping loops used for trapping of beasts of prey in all countries. We know places, where we can find a tiger. After we trap it, we immobilize it with a special pneumatic carbine equipped with flying syringes (drugs harmless to health injected to animals) and then put on its neck a satellite collar.
—How many times did you manage to perform this procedure ?
—We marked several tigers including one tigress thrice. In autumn 2008 it was trapped in a loop twice at an interval of several days, and as we were not satisfied with
the quality of work of the first collar, we had to change it. However, soon communication with it broke off, and we received no signals. We monitored movements of the animal by a microwave transmitter installed in parallel. Fortunately, in October 2009, Sergha (as we called the tigress) was trapped again, and we found that the antenna for data transmission via a satellite system was gnawed off by its cubs, when they played with their mother's "decoration", but the instrument worked properly and accumulated invaluable information during a year, which we copied and analyzed. In the course of this time, 1,222 locations were received, as the tiger's whereabouts were registered thrice a day. This instrument has no analogs. It appeared that its range of movements equalled almost 900 hectares. The tigress moved along the same places. As we did not intend to harm it, the tigress did not take the loops as a threat. However, the reaction to such traps is different in various species. The 18-month-old son of Sergha also has a collar on. It is a period, when young animals leave their mother, and a family breaks up. For the time being nothing is known about this period in the tiger's life: where young animals move to, and how they enter a social group of animals inhabiting the given territory.
The fate of the third animal under observation was dramatic: in the spring 2009, the tiger was orphaned through the fault of poachers, and workers of the Tigr Special Inspectorate trapped the cub and passed it to a special nursery, an open-air cage measuring 1 hectare, where it was taught to find food independantly. In September at the age of 18 months it was set free to the taiga, and now we are monitoring its movements via a satellite collar.
Recently we managed to trap and mark one more tiger, Sergha's husband and father of its 18-months-old son, we discussed above. Thus, we are monitoring now a whole family of tigers.
Apart from them, other beasts of prey fall into traps, such as brown and Himalayan bears. They also collars on and we are monitoring them. It is important as the tiger is fighting for food with the bear, and scientists have to understand how these animals interact.
—Do you fix your observations on a photo or cine film?
—We have the so-called photo traps, i.e. digital cameras with infrared flash, which allows shooting in darkness. It is believed that tigers do not see them. Thus, in places, which they systematically visit, we have installed more than 20 sets of such "assistants" and received
around 300 photos of stripped animals inhabiting the territory under consideration. As a result, we can identify each of them individually according to the skin pattern. At present a total of 6-7 individuals live in the controlled area.
By the way, these instruments record also badgers and hoofed mammals, tigers use as food. We installed a matrix of photographs in different biotopes to assess abundance of different species there. It appeared that in winter the beast chases Manchurian wapiti and wild boars, in summer it eats raccoon-dogs and badgers. One of our tasks is to determine the structure of tiger's feeding and to find out the role of the wild boar, Manchurian wapiti, axis deer, etc. in its "menu".
Within the framework of our program we are studying the main summer food ingredient of the tiger, i.e. the badger, and have found out that the number of this animal is drastically changing and depends on a number of factors, in particular, on infections. There is such a disease as babesiosis caused by parasitic protozoa (Babesia genus), which exist in blood erythrocytes of rodents. This disease is fatal for badgers, its outbreak results in a sharp drop of its number and creates a serious problem for tigers. Little is known about diseases of wild animals: Do beasts take them up from victims or what diseases are most frequent for beasts? There is another problem, which is in the focus of attention of Natalya Yesaulova, Cand. Sc. (Biol.), a specialist from Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology. Apart from studies of infection carriers, we, in cooperation with some temporary staff members, collect tigers' excrement in the whole area of their habitat, starting from the Khabarovsk Territory, and then analyze this material and separate parasites.
By the way, in the course of the Amur Tiger project, very interesting studies were carried out to determine the number of striped beasts based on the molecular-genetic analysis of tiger excrement. This is a pilot work in all ways, including methodology.
—How large is the territory covered by researchers engaged in the "Amur Tiger" project? Do you use in your system of observations the existing monitoring sites designed for calculation of the number of tigers?
—We have other objectives. Indeed, 16 areas have been chosen for monitoring, which adequately reflect the tiger habitat, though it is impossible to cover the entire natural habitat. Every winter game wardens register the number of footprints there. But we are not interested in the change of tiger population. We are studying the spatial structure of the population of this rare animal and peculiarities of the territory use by it, directions and scale of its movements, intrapopulation genetic variability, and peculiarities of reproductive biology of species. I have already mentioned such objectives of the program as identification of the character of interaction between the tiger and other big beasts like brown and Himalayan bears, determination of its liability to different diseases, assessment of food supply state and factors threatening vital activity of our object.
In search of a territory suited for our research, we traveled over the whole Far East and chose the Ussuri Reserve of the RAS FEB. Its Director Andrei Kotlyar and Deputy Director Mikhail Litvinov, Cand. Sc. (Biol.) are participating in our program. Recently the American scientists, who work in the Sikhote Alin Reserve (we cooperated with them in developing the research strategy and, in particular, with Dale Mikkel, director of the representation of the Wild Animal Preservation Society), received important data: today within the Russian part of the Amur tiger natural habitat there are two genetic groups of this subspecies— Sikhote Alin and south-western (on the lands of the Ussuri Reserve), which are separated by a technogenic corridor passing between Vladivostok and Ussuriisk along the Razdolnaya riverbed. Michael Rasselo and Philipp Henry from the British Columbia University have demonstrated that an effective size of national tiger population* (27-35 individuals) is less than its actual number (approximately 500) more than 10 times, which can cause irreversible degradation of the subspecies, if no steps are taken to eliminate the dividing barrier. This
* Effective size of species is always less than the actual number of population of animals due to available species incapable of reproduction or distortion in sex ratio. -Ed.
concerns, in particular, the tigers living in the southwest of Primorski Krai.
The Amur Tiger program envisages different research trends: genetic and hormone-containing. Besides, we are developing and use the so-called noninvasive methods, which allow to get biological information on animals on the basis of their excrement. Pavel Sorokin, Cand. Sc. (Biol.), a staff member of our institute, is studying genetic peculiarities of Amur tigers by isolating DNA from their excrement. Due to this work, we know "by sight" not only all tigers on the reserve territory, but have also established blood relations existing between them. Sergei Naydenko, Cand. Sc. (Biol.), a leading research assistant of the institute is studying the state of their genital system and hormone-containing status, and we set up a special unique laboratory for this purpose. Today, apart from photos and description of morphological features, we have genetic and hormone-containing certificates for each tiger. It must be emphasized that this job was completed less than in 2 years and not in vain, as the collected information was an important argument in development of a strategy of endemic preservation in our country.
—Is the time, which has elapsed since the construction of the technogenic corridor, enough to connect the genetic changes of tiger population with this fact?
—Today all things happen very quickly in the world, therefore we are in a hurry to work out preventive measures. We exchange information with our foreign colleagues, and all our joint efforts are focused on preservation of the Amur tiger. We have to inform business organizations in advance, how to protect rare species from negative influence. Unfortunately, environmental assessment is undertaken now not for all objects under consideration. There is no satisfactory cooperation between different departments, namely, timber and hunting industries, and the Ministry of Natural Resources. Besides, there is no feed-back connection between state structures and environmental institutions. In the course of working out any project, irrespective of its regional or federal status, it is necessary to invite biologists, who can explain, how to minimize losses—possibly in a number of cases to decrease the factor of anxiety for the tiger, say, to transfer the planned construction to some other place. It goes without saying that such steps need scientific substantiation.
For instance, data on movements of animals enable us to clarify our ideas on the impact scale of economic activity on their habitat. Today we know that the tigress (Sergha) walks around a territory, which twice exceeds the Ussuri Reserve area. Consequently, human behavior should be corrected adequately outside its borders too.
—Do you propose creation of new wildlife reserves?
—The tiger lives everywhere in the territory of the Far East, and it is impossible to cover it with a network of wildlife reserves, as the region must develop new lands. But the economic activity should be regulated. For example, felling of cedar and oak should be prohibited, as they form a food basis of hoofed mammals, who in their turn serve as food for beasts of prey. Game husbandry should apply all efforts to stop poaching. In the process of construction of highways, it is necessary to envisage ways for animal migration, as it is planned during reconstruction of the Razdolnoye-Khasan road with a 500 m tunnel (it will pass through a volcano).
— The previous strategy of the Amur tiger preservation of 1996 produced fairly good results. According to estimates, in a period of its realization the tiger population increased from 415-476 to 428-502 individuals in 2005. Thus, human activity potentially dangerous for tiger was limited at that time, wasn't it?
-The success of perspective projects for tiger preservation depends mainly on the extent of their integration into long-term programs of territorial development. In the 1990s, this goal was achieved as there existed an appropriate regulatory and legal base. At that time the problem of preservation of the existing population was clearly defined. Needless to say that tiger hunting as well as trapping of its cubs for zoological gardens were forbidden. Today we witness other economic conditions in our country and other structures of environmental institutions. This is one of the main reasons, why the government has initiated working out of a new strategy. The working group includes Moscow, Far-Eastern and foreign specialists.
— Who is responsible for realization of the Strategy of the Amur tiger preservation ?
-The RF Ministry of Natural Resources and Ecology is responsible for preservation of rare species entered in the Red Data Book.
—Could you name most negative factors of impact on the vital activity of tigers—poaching, territorial development or wood felling?
—All factors, which adversely affect tigers (we should add here infectious diseases causing mortality of animals, tigers' food), are equally important. They cannot be compared. Our new strategy describes each of them and considers measures to avoid consequences.
— What kind of cooperation will be between countries, where the Amur tiger is or was found some time ago?
—Korea is planning to bring the Amur tiger to the country and try to create its new population. Similar projects exist in Iran and countries of Central Asia-Turkmenistan, Kazakhstan and Uzbekistan. China intends to restore the number of tigers. For this purpose, in particular, our countries have to organize a transbor-der reserve.
—Is the tiger going to cross the Russian-Chinese border?
—Quite probably, but we do not know for sure, when and how often it does that. Satellite collars appeared in our arsenal only in 2008, and they will be helpful. Therefore, one of the tasks of the national project is to trap tigers in an area of engineering constructions on the border, if they come there, and put collars on them. At the present time a group headed by Viktor Lukarevsky, Cand. Sc. (Biol.), a research assistant at our institute, is working there.
—Records of the last years proved that the number of tigers in the Far East of our country has decreased starting from 2005. Why?
— It is true, 16 monitoring sites registered decrease in the quantity of footprints. Where does the reason lie? It is too early to draw far-reaching conclusions. The point is that tigers were registered usually in wintertime, but winters were cold and snowy for the last years, and tigers could just decrease activity of their movements. Real factors of the negative impact on the Far-Eastern population surely exist, but such quick results are rather doubtful. At least I am skeptical about information on a 40 percent decrease in the tiger population.
—But the situation is not so simple, as the fate of the Amur tiger greatly depends on people, but in most cases we are not ready to give up our interest for abstract though good goals. It is no secret that for a majority of people preservation of a rare species is just insignificant words. Then why bother about such things ?
—The tiger is atop of a unique energy pyramid called coniferous-latifalious forests in the south of Russian Far East. Preservation of a stable endemic population in its natural habitat means existence of an adequate bioceno-sis necessary for survival of Mankind. That is what should be understood and realized. It is not the tiger, who should adapt to people, who live how and where they want, but we must fit in its natural habitat by our activity, including the whole economic infrastructure.
Опубликовано на Порталусе 30 августа 2021 года
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