THE ANIMAL FILES

Polar bear

Ursus maritimus

Sea ice is hunting habitat, not just a cold floor.

Polar bears rely heavily on seals and use Arctic sea ice as habitat. Their breeding cycle includes a specialised denning period for pregnant females and prolonged care of cubs.[2]

Follow the evidence ↓
Polar bear
Image: Alan Wilson · Commons · CC BY-SA 3.0
Food on the ice
Ringed seals are important prey.[2]
A den for birth
Pregnant females overwinter in dens.[2]
Growing beside the mother
Cubs commonly remain with their mother for about two years.[2]

Food on the ice

Ringed seals supply much of the prey, with bearded seals and other animals also taken. Whale remains can provide food in some regions. Scavenging and hunting both connect bears with the Arctic marine food web.[2]

A den for birth

Pregnant females enter protected dens for birth and early cub development. This differs from a claim that every polar bear disappears into a winter den; sex and reproductive state matter.[2]

Growing beside the mother

Small litters and extended care mean a successful reproductive cycle spans years. The mother supports cub development beyond the den, so leaving the birth shelter is not the end of dependency.[2]

A COMMON MIX-UP

Do all polar bears spend winter in maternity dens?

No. Maternity denning is associated with pregnant females.[2]

TRY A LITTLE REASONING

Why is sea ice more than a resting surface for this bear?

Reveal the explanation

It is habitat associated with access to seal prey, connecting the bear to marine food.[2]

Sources & editorial notes

Original explanations, checked against the sources below. The image has its own credit and licence above.

  1. NCBI Taxonomy — Ursus maritimus
  2. U.S. Fish & Wildlife Service — Polar bear

Last fact check:

One discovery leads to another

Brown bear“Brown” is a species name, not a reliable colour swatch.Ursus arctos ↗WolfA pack is a social family, not just a contest for a title.Canis lupus ↗CoyoteA pounce, a den and a chorus are three different clues.Canis latrans ↗