April 12, 2017
Researchers at the University of
Alberta have demystified the way that polar bears search for their typical prey
of ringed seals. The answer, it turns out, is simple: they follow their nose
using the power of wind.
Using satellite telemetry data
collected from 123 adult polar bears in Canada's Hudson Bay over 11 years, the
researchers merged the movements of polar
bears with wind patterns
to explore how they looked for seals.
They hypothesized that when a
bear smells prey, it moves up-wind to find it. But what is a bear to
do before it smells anything at all?
"Predators search for prey
using odours in the air, and their success depends on how they move relative to
the wind," explained Ron Togunov, University of Alberta alumnus and lead
author on the study. "Travelling crosswind gives the bears a steady supply
of new air streams and maximizes the area they can sense through smell."
While this phenomenon had been
suspected in many animals, it had not been quantified in mammals until now.
The best conditions for olfactory
hunting, explained UAlberta professor Andrew Derocher, co-author and renowned
polar bear expert, takes place at night during the winter.
"Crosswind search was most
frequent when winds were slow, when is is easier to localize the source of a
certain smell, and at night when bears are relatively active and when vision is
less effective, so bears rely more heavily on their sense of smell."
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