Inside a bear’s snout lies a rare world.
The ursine nostril is lined with an unlimited sheet of specialised tissue, referred to as the epithelium, which is embedded with scent-detecting nerves. Just like the human epithelium, these cells have the distinctive capability to regenerate themselves (in contrast to most different nerves). However a bear’s epithelium dwarfs our personal. “It’s a lot, a lot bigger than a human’s,” defined Heiko Jansen, a neuroscientist who researches human and animal physiology at Washington State College. “It is a number of orders of magnitude bigger.”
And mendacity above a bear’s nice muzzle, scrunched below the mind, sits the olfactory bulb — a tube-shaped construction that connects a bear’s profusion of nostril nerves to different elements of its mind. Jansen’s measured this mind construction. It is about 5 instances the dimensions of a human’s.
Although analysis on bear olfaction is scant, the consequence of this highly-evolved scent structure is indeniable.
“It is clearly clear to all people that bears have an amazing sense of odor,” mentioned Jansen.
“I’d characterize a bear’s sense of odor as advanced and simply as necessary to their lives as sight is to people,” mentioned Mike Fitz, a former park ranger at bear-filled Katmai National Park and Preserve and at present a resident naturalist for the wildlife livestreamers explore.org.
Bears’ dependence on extraordinary olfaction creates a actuality that we are able to think about, however by no means actually know. Their very existence could be swamped in potent odors.
“It is a completely different world,” mentioned Andrew Derocher, a polar bear biologist on the College of Alberta.
Katmai Nationwide Park’s Bear 747 sniffing round his realm.
Credit score: NPS / B. MOSBROOK
What kind of world?
It is a world in which you will be roaming by way of a river or Arctic plains by your self, however you’d have a agency consciousness of the presence of different bears (or anybody else) round you, even when they’re nowhere to be seen. The presence of others wafts by way of the air.
“You’re by no means actually alone,” mentioned Derocher.
It is a world by which details about different people is saved on the bottom, timber, and grass, lengthy after they’ve gone elsewhere.
“Sound and sight are ephemeral,” famous Fitz. “Scent lingers far longer. I may journey by way of an space and piece collectively tales of who was there previous to me with out having to see or hear them.”
Polar bears, for instance, will cross a path of bear prints and promptly sniff the frozen earth. In some instances, the male bears will flip round, maybe sensing a dangerous or uninviting meeting with another bear. But when they understand a possible feminine mate, “they will comply with [the scent] like loopy,” mentioned Derocher.
“You’re by no means actually alone.”
Male brown bears have adopted an identical technique. The bears obsessively pursue a feminine’s scent in the event that they understand she’s in warmth. It turns into a drawn-out chase, usually by way of dense forest. “The male can use his highly effective sense of odor to comply with her path nearly precisely even when he cannot see her,” mentioned Fitz.
It is a world that may disturb or overwhelm us.
“If I had been abruptly endowed with a superpower like a bear’s sense of odor, I believe I could be shocked initially by the world of odor,” mentioned Fitz.
Maybe day by day life for a bear is like perpetually strolling round a piquant landfill, a fish market, or a New York Metropolis subway automotive in sweltering July. Or perhaps it is extra like a perfumery.
It is a world we’ll by no means fairly perceive.
“We discover sure issues revolting based mostly on odor — different animals simply discover them irresistible,” mentioned Jansen, noting animals that eat their very own poop.
Katmai Nationwide Park Bear 480 “Otis” and his massive muzzle.
Credit score: nps / n. Boak
Bear cranium displaying the place olfactory neurons result in the mind’s olfactory bulb.
Credit score: Heiko Jansen
Certainly, we do not ever know what animals are actually pondering, what they perceive, and the way they view the world by way of their full of life eyes and enormous nostrils.
“What would it not be prefer to odor like a bear?” requested Jansen. “I do not suppose we might ever actually know.”
However we do know that bears have olfaction powers maybe many instances stronger than bloodhounds. “[Bears] are most likely extra delicate than a bloodhound to smelling various things,” Jansen famous.
Realizing simply how highly effective this olfaction is, although, is an open query.
“We all know bears have a wonderful sense of odor however there are few research that quantify simply how good it’s,” defined Derocher.
That leaves room to marvel.
“You hear all kinds of tales,” mused Jansen, “like bears can odor a carcass from miles away.” “There’s most likely some fact to that,” he added. “However there hasn’t been quite a lot of scientific analysis to again up these assertions.”
However one factor is definite. Bears depend on scent for survival. That is as a result of they must get fat. They solely have a restricted period of time to amass fats reserves earlier than the good, annual winter famine, also called hibernation, begins.
“Relating to bears it’s survival of the fattest,” Derocher mentioned emphatically.
“Their entire lives revolve around food,” mentioned Jansen. “They need to get fats within the fall and hibernate. It is no shock that quite a lot of what they do is predicated upon their sense of odor.”
“It’s survival of the fattest.”
Bears usually stand erect within the wild, with their muzzles prolonged into the air to “see” what’s on the market. The winds might carry hints of a meal within the distance, maybe miles away. “Bears are working the winds on a regular basis,” famous Derocher.
With out bears’ extraordinary capability to not simply understand scent — however perceive a wealth of data saved in these scents like a thumb drive — the big omnivores (some effectively over 1,000 kilos) won’t survive within the harsh, aggressive wilds.
“For those who’re a bear and also you misplaced your sense of odor, I do not suppose you’d be a bear for much longer,” mentioned Derocher.
This story was initially printed in October 2019.
