In spring, 22,500 years ago, a large old male mammoth died in a sheltered hollow in the full-glacial tundra of Yakutia in N. Siberian, near Yukagir. Mud slumped over him in the summer and he was frozen in the permafrost. His body was discovered in 2002; his head with its impressive tusks, front legs, and part of the stomach and intestinal tract were preserved. What did the mammoth eat?
A 6-ton mammoth would need to eat about 180 kg of plant material each day. Therefore, dung preserved in the lower intestine was subjected to a multiproxy array of analyses both botanical (pollen, spores, and macrofossils) and biochemical (plant DNA, biolipids, fecal biomarkers, bile acids), to determine the mammoth’s diet. The dung was 80% grassy material, herbs, and mosses and 20% dwarf-willow twigs, identified as Salix arctica. The first sign of a new annual ring in the twigs and the presence of well developed leaf primordia in the Salix buds indicate ingestion in early spring. Spores of coprophilous fungi inside the intestine demonstrate coprophagy; the mammoth ate dung. Modern elephants and many herbivores show coprophagy. The mammoth lacked bile acids, just like modern elephants, and their absence in the dung implies that the mammoth ate mammoth dung.
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| Salix arctica twigs and remains of Salix leaves, twigs, and fruit capsules Some macroscopic plant remains from the Yukagir mammoth dung |
Botanical analyses of the dung using pollen, plant macrofossils and mosses, and plant DNA showed that the mammoth lived in dry, windy, dusty, treeless tundra dominated by grasses, Kobresia myosuroides (sedge), Salix arctica, and herbs; the so-called ‘Mammoth Steppe’. He also grazed damper vegetation by streams and snow-beds. Seeds of snow-bed plants in his last meal indicate that these had already been uncovered in early spring and were eaten with the new vegetation. Previously, based on the results of pollen analyses, the treeless ‘Mammoth Steppe’ has been reconstructed as an extinct (no modern analogue), grass-rich biome over Beringia (the area of Siberia and Alaska and the linking Bering Land Bridge). It was productive enough to support herds of large grazing animals and their predators. Further palaeoecological work involving plant macrofossils and more detailed pollen identifications has shown that the vegetation was not uniform but was differentiated according to water supply, depending on wind exposure, slope, aspect, snow-lie, etc. into a mosaic of communities reminiscent of remnant areas of grassy tundra in Siberia and Alaska today. Summer temperatures were only a little cooler than they are today with clear skies and low precipitation but winters were cold. Sparse snow cover allowed exposed grasses to provide adequate winter fodder for the herds.
The Yukagir mammoth was old, as shown by his tusks and his worn teeth. The willow twigs were broken but not crushed, so perhaps he was unable to obtain sufficient nutrition from his food. He suffered from ankylosing sphondylitis in his upper back, so maybe he ate a lot of willow as self-medication to obtain pain relief (aspirin). The stress of surviving the bitter winter proved to be too great and he lay down in the sheltered hollow and died.
Reference:
‘The ecological implications of a Yakutian mammoth’s last meal’. Bas van Geel, André Aptroot, Claudia Baittinger, Hilary H. Birks, Ian D. Bull, Hugh B. Cross, Richard P. Evershed, Barbara Gravendeel, Erwin J.O. Kompanje, Peter Kuperus, Dick Mol, Klaas G. J. Nierop, Jan Peter Pals, Alexei N. Tikhonov, Guido van Reenen, Peter H. van Tienderen (2008). Quaternary Research 69, 361-376.