Tag Archives: distribution

Ancient polar bear remains explained by sea ice and polynyas: my peer-reviewed paper

My open-access, peer-reviewed paper on the ecology of ancient polar bears in relation to sea ice has just been published in Open Quaternary. It’s called ‘Polar Bear Fossil and Archaeological Records from the Pleistocene and Holocene in Relation to Sea Ice Extent and Open Water Polynyas’.

A unique compilation of more than 104 polar bear skeletal records from the Holocene and late Pleistocene shows that most ancient remains are associated with existing or ancient open water polynyas or the expansion of sea ice during past cold periods. This big-picture analysis indicates that as they do today, polar bears were most commonly found near polynyas throughout their known historical past because of their need for ice-edge habitats.

Read my longer summary below and download the paper here. This is a much-updated and expanded analysis based on an informal study I did in 2012.

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Polar bears are distributed throughout their available habitat

All Arctic sea ice habitats that are currently suitable for polar bears have polar bears living in them 1 – even the southern-most regions of Hudson Bay that are well below the Arctic Circle (see previous post on polar bear numbers here).

Have a look at the maps below and see how well the current maximum extent of sea ice correlates with the present range of polar bears around the Arctic.

Fig. 1. Sea ice extent at April 25, 2012, from NSIDC (the winter maximum). Note that although there is sea ice in the Sea of Okhotsk (top right of the map), polar bears do not currently live there nor is there any evidence they ever did1.
Compare to the polar bear’s official range below.

Fig. 2. The global range of the polar bear, showing the 19 regional subpopulations. Map from Polar Bear Specialist Group (PBSG), with a few extra labels added.

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