Chapter 1: How far north?

How far north have they found the remains of the bison in North America and Siberia? What have scientists found out now about this? In what kind of a climate has it lived up there? On what kind of a plant-cover has it grazed in the Far North?

The frozen remains of the steppe bison, they have found in northwestern North America and northern Siberia, up to the shores of the Arctic Sea. In northern Siberia, they have found its frozen remains up to Cape Chelyuskin, at the northern tip of Taimyr Peninsula, at 77.5°N. See, please, also map of late Pleistocene range of steppe bison in Kahlke, R.-D. 1994:20. The bison has lived up there on zonal steppe and forest-steppe, not on arctic tundra. In what kind of a climate is the bison living now at the northern limit of its range in Eurasia and North America? How far north is the bison living now? Or how far north has it lived until one or two hundred years ago, before man killed it off? In what kind of a climate is it living up there, at the northern limit of its range?

The bison has lived in historical times (or is still living) in North America and Eurasia at the northern limit of its range, in this climate: 140 (120-160) days above 5°C. 90 (70-150) days above 10°C. 34.5 (27-47) kcal cm² mean annual net radiation at earth’s surface. 1700° (1400°-2000°) 10°C temperature sum. 17.0° (16-19) mean July temperature. 300 (250-350) mm annual potential evapotranspiration (P.E.). There is either no permafrost at all, or only sporadic permafrost at its southern limit.

In Eurasia, the northern limit of the range of the bison lies now about 1,700 (1500-2000) km further south. And in North America it has moved some 1,300 km further southeast.

During the time of the woolly mammoth, the steppe bison in North Siberia and Yukon/Alaska was usually the most numerous large mammal. It has lived then "everywhere": in the large river valleys, in the smaller mountain valleys, higher up, on the slopes and tops of the hills and mountains. Today, the bison is able, to live up there now only at a few small areas, in fertile lowlands.

Bison in North America, in historical times, its northern limit

The bison in historical times, at the northern limit of its range, with the annual net radiation at the earth’s surface, in North America. This is marginal bison habitat. Historical range of bison in North America in, Yukon Bison Management Plan 1998 to 2003, July 1998. And, Status report on Endangered Wildlife in Canada 1987, December 1987. Annual solar net radiation at earth’s surface, from, R. A. Bryson and F. K. Hare, Climates of North America, 1974.

The annual net radiation at the bison’s northern range in North America varies from 25-40 kcal/cm². Its average is 32.5 kcal/cm² year.

During the time of the woolly mammoth, large herds of the steppe bison have lived in northwestern North America (Alaska, Yukon, and Northwest Territories) up to the shores of the Arctic Sea, up to Barrow, northern Alaska, and Baillie Island (on the continental shelf), east of the Mackenzie Delta, in the Northwest Territories. Barrow has now an annual net radiation of about 11 kcal/cm², and Baillie Island about 7 kcal/cm². The northern end of the Great Slave Lake lies about 700 km south of Baillie Island. The Great Slave Lake area has now an annual net radiation of about 25 kcal/cm².

This means: When the large herds of steppe bison were grazing at the shores of the Arctic Sea, near 71°North, there had to be then an annual net radiation at the earth’s surface of at least 25 kcal/cm². Further south in northwestern Canada, near 60°North, there had to be then a mean annual net radiation at the earth’s surface of about 40 kcal/cm². In an arctic and subarctic climate that is not possible. The climate up there had to be then temperate, without an arctic winter.

Bison in Eurasia, in historical times, its northern limit

The bison in Eurasia, in historical times, at the northern limit of its range, with the annual net radiation at the earth’s surface. This is marginal bison habitat. The annual net radiation at the northern limit of the bison’s range in Eurasia varies from 25-33 kcal/cm². The average is 28.5 kcal/cm² per year. Range of bison in historical times, from, V. G. Heptner 1966 p.487, Map Fig. 132. Net radiation from, World Survey of Climatology, 1A (1985) Map Figure 7, by A. Kessler, and from, M.I. Budyko, Global Ecology 1980, Map Figure 7. Moscow.

During the time of the woolly mammoth, large herds of steppe bison have grazed in northern Siberia up to the shores of the Arctic Sea. In Central Siberia, on Taimyr Peninsula, one has found their remains up to the northern part of Taimyr Peninsula, up to about 77°N. Northern Taimyr has now an annual net radiation of about 5 kcal/cm² at the earth’s surface. Until about 100-200 years ago, the bison has lived in Central Siberia about 2240 km further south in latitude. In Eastern Siberia, the bison has lived in historical times up to the headwaters of the Lena River, near 61°N. From Cape Chelyuskin, at the northern tip of Taimyr Peninsula. That is about 1900 km further south in latitude.

This means: When large herds of the steppe bison were grazing in the Far North, up to 77° North, together with the wild horse and the woolly mammoth, the mean annual net radiation at the earth’s surface up there had to be then at least 25 kcal/cm². And further south, near 60°N, the annual solar net radiation at the earth’s surface had to be then about 40 kcal/cm². In an arctic and subarctic climate this is not possible. From this I do conclude: When the bison was grazing in northern Siberia, up to about 77°N, the climate up there had to be temperate, without an arctic winter, without any continuous permafrost.

Prairie bison grazing in summer on South Canadian bison ranch. From: Bison Pastures and Grazing Management (1998:5). Published by Grazing and Pasture Technology Program (APT)