How keen is a wolf’s sense of smell?

Imagine simply in­hal­ing and be­ing able to tell who has passed by and how long ago, what sex they are and what their gen­er­al health is, where they’ve been, what they’ve eaten and what mood they’re in.

To a large de­gree, a wolf nav­ig­ates the world through its sense of smell. The tip of its nose is a com­plex land­scape of minute ridges and creases, which, when com­bined with the out­er edges of nos­trils, cre­ates a pat­tern as dis­tinct as a hu­man fingerprint.

Each nos­tril can be moved in­de­pend­ently, al­low­ing wolves to de­term­ine which dir­ec­tion a par­tic­u­lar scent is com­ing from. Inside the broad snout are ap­prox­im­ately 280 mil­lion scent re­cept­ors, a princely amount when com­pared to a German shepherd’s 225 mil­lion, a dachshund’s 125 mil­lion and hu­mans’ scant five to six million.

A wolf’s nose alerts them to danger, the pres­ence of pack mem­bers or en­emies, fe­male wolves in heat and prey. Each wolf has dis­tinct­ive scent glands on dif­fer­ent parts of their body so smells unique, at least to oth­er canids.

Scientists know that wolves can smell prey 2.5 kilo­metres (1.5 miles) away. Gordon Haber, who spent most of his life re­search­ing wolves in Alaska, was con­vinced that wolves could smell a dead moose or cari­bou bur­ied un­der three metres (ten feet) of snow, even if the wind was blow­ing the wrong direction.

In Wolves on the Hunt, a ra­dio-collared fe­male wolf with pups makes a beeline for a cari­bou herd more than 100 kilo­metres (62 miles) distant.

What sur­prised the re­search­ers was the tim­ing of the wolf’s jour­ney and the re­l­at­ively straight line she made for the cari­bou. The week be­fore her trek, the av­er­age daily dis­tance between her den and the cari­bou was 242 kilo­metres (150 miles). The day she left, it had nar­rowed by more than half.

If the wolf had veered to the north­w­est, she might have missed the herd en­tirely or not found them un­til later. There’s no way to know if she smelled the un­gu­lates from her den, picked up their scent part­way through her jour­ney or simply headed in the dir­ec­tion she’d found cari­bou before.

But cari­bou are highly mo­bile so the wolf couldn’t have de­pended on memory alone. The re­search­ers spec­u­late that if a hu­man can smell smoke from a forest fire more than 100 kilo­metres (62 miles) away, why couldn’t a wolf smell a cari­bou herd from the same distance?

Photo cour­tesy Wolf Conservation Centre.

WCC is an en­vir­on­ment­al edu­ca­tion or­gan­iz­a­tion that teaches people about wolves, their re­la­tion­ship to the en­vir­on­ment and hu­mans’ role in pro­tect­ing their future.