What have other workers found out about the Amur tiger? How far north is the tiger living in the northernmost part of its range in Russia’s Far East, at the Amur River? In what kind of a climate is this large cat living there? At which density? On what kind of a plant-cover does it live there? How much prey biomass is there per square kilometer?
The International Union for Conservation of Nature and Natural Resources, in Switzerland, reports in its book The Amur Tiger in the USSR (1980):
“Probably the most northern point of the tiger’s main habitat in the Amur basin was on the Gorin river (51°N). As regards penetration by individual specimens they were similar here to those in the upper Amur – relatively frequent and far-reaching. …
“It can hardly be hoped that the number of tigers within the reserve will grow. Its present level is probably a maximum for the conifer/broadleaved forests of central Sihote-Alin. It is noteworthy that the number of tigers recorded during the counts has stabilized in the course of the last 5 years. On 25-29 January 1977 the minimum number of tigers counted by researchers on the routes amounted again to 6 or 7.
“From these data (and taking into account the home ranges of the animals with regard to the reserve boundaries) the density of the tiger population is equivalent to 0.13 – 0.32 individuals per 100 km˛. This corresponds to the number suggested by S. P. Kutcherenko (1973) for the ‘optimum biotopes’. But the tigers inhabit Sikhote-Alin reserve unevenly because about one third of the territory has types of vegetation, which the animals virtually do not use. After making appropriate correction, a higher density should be expected – about 0.3 – 0.4 individuals per 100 km˛. These last figures in all probability reflect the natural level near the northern limit of the tiger’s range.” (1960:6, 7, 14).
0.3 tigers/100 km˛ = 1 tiger per 333 km˛. And 0.4 tiger/100 km˛ = 1 tiger/250 km˛.
“Lazovsky reserve is approximately one-third the size of Sikhote-Alin reserve. Results of the counts made in three successive winters, starting in 1974-75, are similar – although different individuals were recorded – but their distribution had changed considerably. The minimum number of animals recorded during the whole winter plus special tracking enabled us to increase this figure to 10. The total number of tigers visiting the reserve is about twice that – 18-23 in the winter of 1975-76.
“The density of the tiger population in Lazovsky reserve is equivalent to 0.6 – 0.9 individuals per 100 km˛. Detailed research shows that in the coastal part of the reserve – where the animals were distinguished individually – this number may rise to 1 individual per 100 km˛. Either way the density of the population here is 2-3 times higher than in the Sikhoto-Alin reserve.” (1980:14, 15).
0.6 tiger/100 km˛ = 1 tiger/166 km˛. 0.9 tiger/100 km˛ = 1 tiger/111 km˛.
“The depth of snow varies from none at all to about one meter – particularly in February and March. On the southern slopes, especially near the coast, the snow, under the influence of sun and wind, quickly melts. The further from the shore and the higher up in the mountains, the deeper and more uneven the snow cover. Snow 35-50 cm deep and lying for 2-4 months a year is characteristic of the tiger habitat. Under such conditions – and more so in years when there is no snow – the tigers spend the winter quite safely, though from time to time difficult or even critical situations may develop.
“The Sikhote-Alin winter is characterized by infrequent, but heavy snow-falls. The tiger then finds it hard to move and creates a kind of trench when doing so. Even a thin layer of snow causes difficulty. Lumps of ice, frozen on the soles, produce bleeding of the toes: drops of blood can often be found in tracks. …
“In the northern and southern part of Sihoto-Alin the high-altitude zones of vegetation take different forms – as too does man’s impact on the forests. In Sikhote-Alin reserve on the eastern slopes of the mountains, cedar forests predominate; the nearer the sea, the more they are replaced by secondary birch and broad-leaved forest, oak-woods and meadows. The tiger gravitates mainly towards the middle of the river basins. … Above 700-800 m are the coniferous (Abies, Picea) mountain forests, with vegetation of a subalpine type on several summits. These areas, occupying up to 30% of the territory of the reserve, are scarcely ever visited by tigers. The upper part of the basin of the Lolumbe river in the north of the reserve, where the Abies, Picea taiga is dominant vegetation, has no tigers.
“In Lazovski reserve, where conifers are markedly fewer and where the vegetation is more southern in character the tigers occur almost everywhere. … More than half of the Lazovski reserve is covered by (usually) secondary forests, where the Mongolian oak (Quercus Mongolia) predominates. These areas in the south of Sikhote-Alin are a ‘normal’ habitat of the Amur tiger. … The number of tigers depends mainly on food resources and effective protection.” (1980:17-19).
Amur tiger in Russia’s Far East in winter. From: Ronald L. Tilson et al. (eds.), Tigers of the World (1987:394).
How large is the home range of the Amur tiger? And how far does this cat walk there in one day?
“Although scarcity of food may compel some animals to cover 80-100 km in 24 hours (Baikov, 1925), under normal conditions the distance will not be more than 15-20 km.
“According to observations in1970-72 in Sihote-Alin reserve the tigress moved within an area of about 200-400 km˛ and the male tigers within an area of about 900-1000 km˛. These are maximum figures, but yet those given by L. G. Kaplanov (1946) are 3-6 times as large. The differences are accounted for by changes in the density of the population: fewer tigers (as at the time of the early research) mean a larger home range. This fact is confirmed by contemporary observations made in Lazovksy reserve. Here, the tigers being more numerous, the size of the female’s home range is only about 100 km˛ (Zhivotcheno, 1976). When the cubs are little, movement is minimal. L. G. Kaplanow (1948) notices that a tigress with two cubs stayed within an area of 5 x 3 km for three weeks.
“The home ranges of tiger with tiger – or tigress with tigress – are clearly separated or overlap only slightly. At the same time the males cover to a considerable extent the home ranges of the females. Where V. I. Zhivotchenko (1976) did field research, one male and two females lived in the winter of 1973-74. One of the tigresses had two grown-up cubs, while a young, but independent animal periodically joined the second male. In the winter of 1974-75 the young tiger left the home range of their parents, but three little cubs appeared in two new litters (one cub in one litter, two in the other). … Every year a certain number of the females have no young. L. G. Kaplanov (1948) wrote of meetings with un-mated tigresses; in recent years their tracks have been regularly observed in Sikhote-Alin reserve. …
“Tigers hardly ever stay near their prey till the latter is fully consumed; they leave behind 20% - 70% of the weight of the carcass. The remains are sometimes returned to and eaten by the ‘owners’, but are usually devoured by scavengers.” (1980:23-25, 31).
How much biomass of wild ungulates is there in the forests of the Far East, where the Amur tiger now lives? This is usually mixed forests, with oaks and other broad-leaved trees. Professor Andrej G. Bannikov, University of Moscow, has found out about this:
The Far East forests have an average wild ungulate biomass of 2800 kg/km˛. The following kinds of animals are living thee: Moose, wild pig, musk deer, roe, red deer, and reindeer. That is in the national parks. Outside of the national parks, wild ungulate biomass is lower, because people are hunting there and are using some of the land for farming. Otherwise the wild ungulate biomass would there be much higher: Outside of the national parks, the Far East forest zone of the mountains and the mixed forest have an ungulate biomass of up to 1000 kg/km˛, and an average 350-400 kg/km˛. Bannikov, A. G. (1967:259).
The residential tigress, raising cubs, and her male tiger, will be able to live, where there are many wild pigs and red deer: where the wild ungulate biomass is an average 2800 kg/km˛. The tigress will stay there at least as long, as her cubs are small. Later on, when the cubs are larger, she will move with them into areas, where prey biomass is a little lower: down to 1000 kg/km˛. Nomadic adult tigers, without an own territory, not raising any cubs, could also move at times into poorer areas, having a prey biomass of only 350 to 400 kg/km˛.
How heavy is the Amur tiger on the average? And how heavy can the Amur tiger get?
Professor V. G. Heptner: “The body size of the Amur tiger varies much, especially that of the male, which is much larger and heavier. Important is also, that the tiger is able to live a long time, and that it keeps on growing for a very long time, practically throughout its whole life. Under favorable conditions, the animals are well-nourished and even fat. The largest weight of an Amur tiger was 390 kg (Bajkov 1927) and 384 kg (a male; V. P. Sysoev 1952). Bajkov (1927) states as a general upper level even 400 kg. It might be that these figures are a little too high. At least, they do apply to large old males, which have become rare in our time. The existence of animals with a weight of 325, 340 kg and 360 kg, however, is proved. Up to 320 kg for males and up to 180 kg for females are mentioned as a ‘normal maximal weight (Bajkov 1925)’.” (1980:118).
In what kind of a climate is the tiger living now - or has recently still lived -in the northernmost part of its range? Does this prove that the tiger and lion during the time of the woolly mammoth have also been adapted to an arctic climate?
According to the distribution maps of V. G. Heptner et al. (1980) the tiger has lived in the southernmost parts of western Siberia and is still living in Russia’s Far East: at the Amur River. In western Siberia and southeastern Europe, the tiger has lived until a few decades ago east of the Caspian Sea (between Lake Aral and Lake Balkhash) and still further east, till it was exterminated there by settlers. The tiger has lived there mainly close to the rivers, among the dense reeds, hunting the wild pig. In western Siberia, this large cat went up to about 47° to 48°N.
In Russia’s Far East, at the Amur River, the tiger is living (or has lived until quite recently) up to about 52°N. That are residential tigers, with their own territory, raising cubs. Nomadic tigers (without an own territory) have moved at times much further north, into southern Siberia (as shown on map by black dots and broken line). But the nomadic tiger does not reproduce up there. The nomadic tiger, moving at times into southeastern Siberia, does not get there any cubs, also not, when staying up there for a long time, as Prof. Heptner reports. The reason: The tiger is not able to reproduce in southeastern Siberia, because there is too little food, to support a tigress with her cubs.
What does the climate at the northern limit of the tigers range show us? Does it prove that this cat could also have lived in the arctic tundra or dry arctic steppe?
In the northernmost part of the tigers range, at the Amur River in Russia’s Far East, the temperature sum of days, with temperatures above 10°C, is 1600-2000°. In West Siberia, the tiger’s northern range has an annual temperature sum with days above 10°C, of 3500°. In Siberia’s arctic tundra (above the northern tree-line), it is only 200°. That is 9 times less than at the Amur River.
The mean air temperature of the warmest month (July) at the Amur River is about 18°C. At the northern limit of the tiger’s range in West Siberia, the warmest month of the year is 25°C. In Siberia’s arctic tundra, it is usually 3-10°C. And still further north, in the polar desert, where they also have found the remains of the tiger, the lion and the mammoth, only 0-3°C.
Mean annual potential evapotranspiration at the Amur River is now 1000 mm. In the tundra of northern Siberia, mean annual potential evapotranspiration is only 200 mm. And in the polar desert, still further north, it is still lower.
Mean annual air temperature at the Amur River is +2°C to +4°C. At the northern limit of the tiger’s range in West Siberia, +12°C. And northern Siberia has now a mean annual air temperature of only –9°C to –13°C.
In the Amur area, there is now sporadic or scattered permafrost, at least in the mountains, 0-25 m thick. But these scattered pieces of permafrost are lying there beneath a layer of earth, 2-3 m deep, the active layer. No ice wedge is able to grow there. In West Siberia, at the northern limit of the tiger’s range, there is no permafrost at all. In northeastern Siberia, however, there is continuous permafrost, 300-500 m thick, with thick ice wedges. The active layer above it (the surface of the ground, which thaws in summer) up there is only about 20 cm deep. Only on a few well-drained south-facing slopes, the surface of the ground might be able to thaw deeper.
The lion has lived in northern Siberia at least up to about 77°N, as R.-D. Kahlke (1994) distribution map shows us. In Alaska, they have found the remains of the lion up to the arctic coast. And it is very likely that also the tiger has lived then so far north in northern Siberia and Yukon/Alaska. This shows us something, which the proponents of the modern ice age theory will not like at all: This climatic table shows us, how warm it must have then at least in northern Siberia, Alaska, and the Yukon Territory, when the lion and the tiger were hunting up there an the mammoth-steppe.
We should remember here: The climate at the Amur River, where the tiger is living now, represents only the northernmost part of its range: its marginal habitat. That is, the climate, where this large cat is still able to survive. The climate on its normal range, further south, must therefore be still warmer. This shows us:
When the tiger and lion were living in the Far North, at least up to 77°N, the temperature sum with days above 10°C, has been then at least 1600°-2000°.
The warmest month of the year (July or August) has had then a mean air temperature of at least 18°C. The mean annual potential evapotranspiration was then at least 500 mm. And the mean annual temperature of the air of northern Siberia, Alaska and the Yukon, has been then at least +2°C to +4°C.
When the tiger and lion were living in northern Siberia, Alaska, and the Yukon, there has been then no continuous permafrost. And there were no ice wedges, nor arctic tundra, and no polar desert. The Amur area has now at a few places sporadic permafrost, up to25 m thick. But only in the northernmost part of its range: in its marginal habitat. On its normal range, as in the southernmost part of West Siberia, there is no permafrost at all, but the climate down there is subtropical. Also the food, which the herds of mammoths needed, could only have grown in a mild, temperate climate, where there was no permafrost at all. This is only the climate, deduced from the northernmost limit of the tiger’s range, living now at the Amur River. Its normal range – its optimal habitat – had to have, therefore, a still warmer climate.