From Polar Bear Science
Dr. Susan Crockford
My open-access, peer-reviewed paper on the ecology of historical polar bears in relation to sea ice has simply been printed in Open Quaternary. It’s referred to as ‘Polar Bear Fossil and Archaeological Records from the Pleistocene and Holocene in Relation to Sea Ice Extent and Open Water Polynyas’.
A singular compilation of greater than 104 polar bear skeletal data from the Holocene and late Pleistocene exhibits that the majority historical stays are related to present or historical open water polynyas or the growth of sea ice throughout previous chilly intervals. This big-picture evaluation signifies that as they do at the moment, polar bears had been mostly discovered close to polynyas all through their recognized historic previous due to their want for ice-edge habitats.
Read my longer abstract under and obtain the paper right here. This is a much-updated and expanded evaluation primarily based on a casual examine I did in 2012.
Polar Bear Fossil and Archaeological Records from the Pleistocene and Holocene in Relation to Sea Ice Extent and Open Water Polynyas
No Arctic animal is extra iconic than its apex predator, the polar bear (Ursus maritimus). However, its distribution throughout time and house has not beforehand been reported. Natural loss of life skeletal specimens of this species (‘fossils’) are uncommon however archaeological stays are rather more widespread. This historic compilation presents the file of recognized historical polar bear stays from fossil and archaeological contexts earlier than AD 1910.
Most polar bear stays date to the Holocene (the final 11,700 years) and are available from human habitation websites inside the fashionable vary of the species. Specimens discovered outdoors the trendy vary (extralimital) have been documented within the north Atlantic throughout the late Pleistocene (ca. 115,000- 11,700) and the southern Bering Sea throughout the center Holocene (ca. 8,300-4,200 years in the past), together with pure expansions of sea ice throughout recognized chilly intervals.
Surprisingly, the only largest assemblage of this species can also be the oldest archaeological web site with polar bear stays. Zhokhov is without doubt one of the northern-most islands within the East Siberia Sea, Russia which polar bears females nonetheless use at the moment as a denning space. The web site was occupied primarily throughout a brief interval (ca. 8,000-7,900 years in the past) close to the start of the Holocene Climatic Optimum (about 9,000-5,500 years in the past), when the Arctic was hotter than at the moment. Almost 6,000 polar bear bones had been recovered from Zhokhov Island, which represented about 28% of all of the animal stays recognized on the web site.
In nearly all different archaeological websites worldwide, lower than 3.5% of recognized stays had been polar bear. The Zhokhov Island assemblage can also be our first proof of the return of polar bears to the western Arctic after terribly thick sea ice throughout the Last Ice Age (ca. 30,000-19,700 years in the past) drove seals and bears into the north Pacific.
This examine exhibits that polar bear stays are most frequently present in proximity to areas the place polynyas (recurring areas of skinny ice or open water surrounded by sea ice) are recognized at the moment and which doubtless additionally occurred up to now. As a consequence, the oldest recognized fossil (dated to about 130-115k years in the past) and the oldest recognized archaeological specimens (dated to about 8,000 years in the past) had been doubtless related to polynyas as nicely. This sample signifies that as they do at the moment, polar bears could have been mostly discovered close to polynyas all through their recognized historic previous due to their want for ice-edge habitats at which to hunt seals, their main prey.
Citation: Crockford, S. J. 2022. Polar bear fossil and archaeological data from the Pleistocene and Holocene in relation to sea ice extent and open water polynyas. Open Quaternary 8(7): 1-26. https://doi.org.10.5334/oq.107
