Which of the following organisms is least likely to be found in polar regions?

Small animals, like hummingbirds, shrews, etc., have a larger surface area relative to their volume and they tend to lose body heat very fast when it is cold outside. So, such small animals are rarely found in polar regions.

Bergmann's rule states that populations and species of larger size are found in colder environments, while populations and species of smaller size are found in warmer regions. Polar bear, Arctic fox and snowy owl are large animals which reside in polar regions.