Chapter 3: The Eurasian Lynx
Where is the Eurasian lynx (Lynx lynx) living? How heavy does it get? Which kinds of animals does it kill for food? And how much prey biomass must the home range of the residential Eurasian lynx, raising kittens, at least have?
Trotting lynx. Nature Preserve ‘Stolby’ near Krasnoyarsk, East Siberia. Photo V. V. Kozlov. In: V.G. Heptner et al. (1980:476) Fig. 243.
The Russian Professor V. G. Heptner (1980) reports: In northern European Russia in winter the snow hare is the lynx’ main prey. When there are no hares, the lynx will also be rare. The lynx is killing red deer, reindeer, young moose, roe deer, domestic sheep, pigs, dogs, Siberian ibex, and fox. The lynx is hunting everywhere smaller ungulates, mainly roe deer and musk deer, usually when the snow is deep or crusted over. In areas, where there are no ungulates, or where they are rare, the lynx is catching hares, mainly snow hares, and its density depends upon the numbers of the snow hare.
In the mountainous taiga (boreal forest), it catches in winter smaller ungulates (especially roe deer and musk deer). Hares come in second place. Rodents (ground hogs, squirrels, ground squirrels, and mice), pikas and birds (mainly chicken-birds) are playing during the snowless months an important role, but is not its main-food.
Despite its size, the lynx is eating only little. In the Mordwinian Reserve (southeast of Moscow), an adult lynx is eating within 5 winter months about 240 kg meat. In the zoo, the adult lynx gets 1,500 g meat a day. In the Central Forest-Reserve in the district of Welikiye Luki, one lynx is eating on the average in 4 days one snow hare. During one year it devours therefore up to a 100 hares. A lynx family of 1 female and two young animals devours per day one whole hare.
Home range of lynx
The home range of the lynx depends on the number of the lynxes, the number of its prey, and on how easily the prey can be caught. In the circuit of Prioserny in the district of Arkhangelsk, northern Russia, in December, on an area of 30x18 km, there are 13 lynxes. Each had an average 41 km². In the district of Kemerowo, in West Siberia, the lynx is occupying in winter an area of 25-100 km². The European adult male lynx weighs an average 19.6 kg. The female 17.3 kg. The Carpathian lynx in SE Europe: Male 25.7 (15.5-36.5) kg. Female: 19.2 (13.8-29.0) kg. This is the largest lynx. - Heptner, V. G. (1980:437).
The arctic hare (Lepus othus) weighs about 2.5.-3.0 kg. There might be from 400 to 2,400 arctic hares/km². 20-40% of the annual hare production is used by predators. - Grzimeks Enzyklopädie (1987) Vol. 4.
Arctic hares are snow-white throughout the year in the Far North, but the tips of their ears are black. Southern populations on the Canadian and Siberian mainland turn brown in summer. From: Bernard Stonehouse, Animals of the Arctic, the ecology of the Far North (1971:127).
Eurasian Lynx with two Kittens
A family of 1 female Eurasian lynx and two young animals devours per day one whole hare (Heptner, 1980). How much digestible and metabolizable energy must they take in then per day? I do assume here that the mother is also eating the food, consumed by her 2 kittens.
The average adult female European lynx weighs about 17.3 kg. The average adult arctic hare weighs 2.75 (2.50-3.00) kg. The Canada lynx is eating about 85.173% of the snowshoe hare (Saunders, J. K., 1963). The European lynx is able to eat then 2.342 kg from the 2.75-kg arctic hare. That is 824.384 g DM/day (at 35.2% DM). The European female lynx, with her two kittens, when eating one whole adult arctic hare a day, is taking in then 439 kcal DE and 372 kcal ME/kg0.75 day.
This Eurasian lynx has just killed a deer for food. From: Grzimeks Enzyklopädie (1988:613) Volume 3.
Lowest Prey Biomass
How much prey biomass/km² does the European lynx need at least, when raising kittens, in the northern part of its range?
In the district of Prioserny, near Arkhangelsk, in northern Russia, near 65°N, near the coast of the White Sea, in December, 13 lynxes were living on 30x18 km. Each lynx had an average 41 km² (Heptner, 1980). One European female lynx, weighing 17.3 kg and her two kittens is eating 1 whole arctic hare a day. This arctic hare weighs 2.75 kg. In 1 year, this lynx family must kill 1,004 kg arctic hare biomass on its 41 km² home range. The Canada lynx in Central Alberta, W. Canada, is killing about 7.964% of the total prey biomass on its home range per year, when raising kittens. The European female lynx, with her 2 kittens, on her 41 km² home range, on the forest-tundra near Arkhangelsk, near the White Sea, needs then a prey biomass of 307 kg/km², when raising kittens.
This means: The residential, reproducing Eurasian lynx (Lynx lynx) weighing 17.3 kg, is only able to live in this subarctic climate, when there is a prey biomass (of arctic hares) of at least 307 kg/km². And the smaller residential Canada lynx, weighing 8.6 kg, on its 17.8 km² home range, needs a prey biomass of at least 283 kg/km².
Result
The Eurasian lynx (Lynx lynx) is found from NW Europe to eastern Siberia. The average male weighs 19.6 kg, the female 17.3 kg. The Carpathian male lynx in SE Europe may reach 36 kg. The residential female lynx, with two kittens, is living in NW Russia, near Archangelsk, on her 41 km² home range. They are consuming 1 adult arctic hare a day, weighing an average 2.75 kg. That are 365 arctic hares/year (Heptner, 1980).
The Eurasian residential lynx, raising kittens, is only able to live in the forest-tundra, when there is a prey biomass (of arctic hares) of at least 307 kg/km². The African lioness, with two cubs, 6 months old, needs an ungulate prey biomass of at least 3,145 kg/km². That is 10.2 times more than that of the Eurasian lynx in the North-Russian forest-tundra near the White Sea. This clearly disproves the idea, that the cave lion and woolly mammoth were adapted to a severe arctic climate.
The Eurasian lynx (Lynx lynx). From: Grzimeks Enzyklopädie (1988) Volume 3. It ranges from N.W. Europe to eastern Siberia. The average adult male weighs 19.6 kg, the female 17.3 kg. The Carpathian male lynx in S.E. Europe may reach 36 kg. The residential female lynx, with two kittens, is living in N.W. Russia, near Arkhangelsk, near the coast of the White Sea, on its 41 km² home range. They do consume 1 adult arctic hare a day, weighing an average 2.75 kg. That are 365 arctic hares per year (Heptner 1980). The Eurasian lynx, raising kittens, is only able to live in the Far North, in the forest-tundra, when there is a prey biomass (of arctic hares) of at least 307 kg/km². The lynx clearly proves that the much larger cave lion has not lived in the Far North in an arctic climate. There was too little food. The lynx clearly disproves the belief, that the much larger cave lion, during the time of the woolly mammoth, has lived in an arctic climate, like the reindeer and the musk-ox of today. There would have been too little food, to support the residential lion and tiger, raising cubs.
Arctic hares on the Canadian High Arctic Islands. Arctic hares huddle against the winter cold. Protected from the cold ground by their thickly padded hind feet, they have assumed as near a spherical shape as possible in order to conserve heat. From: David R. Gray, The Muskoxen of Polar Bear Pass (1987).
On the 6th of February 2002 at 20:15 p.m., the German television transmitter 3SAT has shown a film about the European Lynx (Lynx lynx), under the title NetzNatur: Luchs. This report dealt with the lynx, which they have re-introduced in the eastern part of Switzerland.
How many lynx are living now again in Switzerland, after they had been exterminated there during the last one to two centuries? How much food does this grown Eurasian lynx (Lynx lynx) need there per day and per year? Which kinds of animals does it mainly hunt there? And how large must its prey biomass of hoofed animals be there at least during the lean season of the year?
The biologist Andreas Moser reports in this film: In Eastern Switzerland 40-60 lynx are living now again. The lynx is hunting there mainly the chamois and the roe deer. A grown lynx kills there 60 prey animals in one year, mainly chamois and roe deer. He kills there each week one roe or one chamois. He devours 3 kg meat per day.
From the hoofed animal, which this cat has killed, about 33% it is not able to eat, like the bones and the contents of the stomach and intestines. The grown European lynx weighs about 19 kg, about twice as much as the Canadian lynx. It needs 3 kg meat per day. To this we have to add 33% un-edible parts (bones, stomach contents, etc.). That is then 3.990 kg live ungulate prey per day, or rounded up, 4 kg. In one year, this lynx needs then 1456 kg living ungulate prey biomass.
The lynx living from hoofed animals (instead of from hares) kills about 10% of the ungulates on his home range per year, namely 1456 kg. That is 60 prey animals per year. On his home range there must be then at least 14.560 kg hoofed animals. That is then 600 hoofed animals (roe deer, chamois, red deer). How large is this home range?
In northern Russia, near the coast of the White Sea, the home range of the residential lynx, raising cubs, is about 41 km². The adult lynx living on small hoofed animals (on chamois, roe deer and red deer) needs then an ungulate prey biomass of 355 kg/km². On his home range there must be then at least 600 hoofed animals (chamois, roe deer, and red deer). So much ungulate prey biomass must be there on his home range during the lean season of the year. Any surplus during the rest of the year is irrelevant.
This means: the largest residential wild cat, weighing about 19 kg, is only able to live, where there is a ungulate prey biomass of at least 355 kg/km² during the poorest season of the year. That is 600 small hoofed animals on about 41 km². Of these it must kill 10 percent, 60 animals per year.
In an arctic climate this is not possible. The arctic tundra (or tundra-steppe) is not able to support a biomass of hoofed animals of 355 kg/km². I would like to repeat here again: So must ungulate prey biomass must be there during the poorest time of the year. Any surplus during the rest of the year is irrelevant. The Canadian wildlife biologists R. J. Hudson and F. L. Bunnel (1980:210) found out: The arctic tundra has a biomass (of caribou and muskoxen) of only 18-26 kg/km², or an average 22 kg/km². Thus, also the much larger cave lion and tiger living in the Far North together with the woolly mammoth, have not been able to live up there in an arctic climate, on an arctic plant-cover. The climate up there must have been then much milder than now, without an arctic winter, without ice and snow.