Inside a bear's snout lies an extraordinary world.
The ursine nose is lined with a vast sheet of specialized tissue, called the epithelium, which is embedded with scent-detecting nerves. Like the human epithelium, these cells have the exceptional ability to regenerate themselves (unlike most other nerves). But a bear's epithelium dwarfs our own. "It is much, much larger than a human's," explained Heiko Jansen, a neuroscientist who researches human and animal physiology at Washington State University. "It's several orders of magnitude larger."
And lying above a bear's great muzzle, scrunched under the brain, sits the olfactory bulb — a tube-shaped structure that connects a bear's profusion of nose nerves to other parts of its brain. Jansen's measured this brain structure. It's about five times the size of a human's.
Though research on bear olfaction is scant, the consequence of this highly-evolved scent architecture is indisputable.
"It's obviously clear to everybody that bears have a great sense of smell," said Jansen.
"I would characterize a bear's sense of smell as complex and just as important to their lives as sight is to humans," said Mike Fitz, a former park ranger atbear-filled Katmai National Park and Preserveand currently a resident naturalist for the wildlife livestreamersexplore.org.
Bears' dependence on extraordinary olfaction creates a reality that we can imagine, but never truly know. Their very existence might be swamped in potent odors.
"It's a different world," said Andrew Derocher, a polar bear biologist at the University of Alberta.
Katmai National Park and Preserve's Bear 747 sniffing around his realm.©Provided by Mashable
What sort of world?
