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Ice-age megafauna in Arctic Alaska: extinction, invasion, survival

Quaternary Science Reviews

By:
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DOI: 10.1016/j.quascirev.2013.03.015

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Abstract

Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age megafauna was more diverse in species and possibly contained 6× more individual animals than live in the region today. Megafaunal biomass during the last ice age may have been 30× greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly bears comprised the predator/scavenger guild. The youngest mammoth so far discovered lived ca 13,800 years ago, while horses and bison persisted on the North Slope until at least 12,500 years ago during the Younger Dryas cold interval. The first people arrived on the North Slope ca 13,500 years ago. Bone-isotope measurements and foot-loading characteristics suggest megafaunal niches were segregated along a moisture gradient, with the surviving species (muskox and caribou) utilizing the warmer and moister portions of the vegetation mosaic. As the ice age ended, the moisture gradient shifted and eliminated habitats utilized by the dryland, grazing species (bison, horse, mammoth). The proximate cause for this change was regional paludification, the spread of organic soil horizons and peat. End-Pleistocene extinctions in arctic Alaska represent local, not global extinctions since the megafaunal species lost there persisted to later times elsewhere. Hunting seems unlikely as the cause of these extinctions, but it cannot be ruled out as the final blow to megafaunal populations that were already functionally extinct by the time humans arrived in the region.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Ice-age megafauna in Arctic Alaska: extinction, invasion, survival
Series title:
Quaternary Science Reviews
DOI:
10.1016/j.quascirev.2013.03.015
Volume
70
Year Published:
2013
Language:
English
Publisher:
Elsevier
Contributing office(s):
Alaska Science Center
Description:
18 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Science Reviews
First page:
91
Last page:
108
Country:
United States
State:
Alaska
Other Geospatial:
North Slope