Cpt Davenport,
Bears have an incredible sense of smell. With all due respect your sense of smell is not even close. It is estimated that Black Bears' sense of smell is about seven times greater than a bloodhound's!
Ref:
https://www.nps.gov/yose/blogs/bear-series-part-one-a-bears-sense-of-smell.htm#:~:text=Even%20bloodhounds%2C%20dogs%20so%20famous,that%20it's%20difficult%20to%20measure.
They also learn to associate human odors with food.
The answer to your question based on testing is, No, Bear canisters and food bags do not prevent Bears from smelling the food odors because they are almost always present on the outside surfaces of the containers. Further, even a small amount of molecules of odor escaping a container, as the air in it expands and contracts during heating and cooling during the day and night, can be detected by a Bear. So while we use tight seals on the lids of our canisters that is mainly to keep water, dirt and tiny bugs out.
Also don't hang food or trash, except perhaps on approved Bear poles in parks and campgrounds that still have them. It too often doesn't work and for that reason a number of places have removed them and installed metal food storage lockers.
Bottom line: Black Bears in particular are nimbler than cats, very intelligent, can see in color and learn easily. Grizzlies are more brutish than nimble and smart. That is why hanging food from bags in trees rarely works in places where it has been done for decades because the Black Bears have learned they can climb out on the limbs or send Cubs out to bend the branch down or break off the limb to get the food. They have even learned to defeat commercial Bear poles by Cubs climbing up and standing on the shoulders of a standing Mama Bear.
That intelligence and love of food is why once they break into a vehicle and successfully get a food reward often times the very next vehicle, they will try will be a car that looks identical in style and color.
That intelligence is also is why there is documented evidence of Bears working together to defeat latches on large trash bins; One Bear trips the latch while another opens the lid. Incredible and true.
In popular places (Yosemite, Sequoia and Yellowstone come to mind quickly) if a Black Bear sees something that looks like food in your car (from past success at getting food in colored wrappers, say on a camp table or trash can) it is probable and peraps likely that they will try to break in. They are very strong and it is usually easy for them to pop a locked car door open or bust out a window. They often leave a poop thank you when they leave, after tearing up the seats looking for the food scraps they smell under them.
The Park Service, Forest Service, BLM as well as California Forest and Park rangers say “a fed Bear is a dead Bear”. Once a Bear is successful at getting human food they will very quickly become repeat offenders and thereby become dangerous to humans. That in turn too often leads to them ultimately being euthanized.
Please seek input from Rangers wherever you camp and dutifully employ their advice on how you can avoid inadvertently feeding Bears and thereby helping create a problem Bear. It is important to do this every time because the situation is constantly evolving. Places where Bears were not historically a problem are now having Bear problems due to the massive increase in visitation and sloppy camper food and waste storage habits.
Factually, this is a people problem not a Bear problem. The Bears are just doing what they have evolved to do The problem is people feeding them intentionally or unintentionally though ignorance or carelessness.
Here are National Park Service, Dept of Agriculture and Calif Parks & Recreation links to proper food storage when camping:
https://www.nps.gov/subjects/bears/storingfood.htm
https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5191168.pdf
https://www.parks.ca.gov/NewsRelease/806
I hope this information is helpful,
P.S. I have been in the Bear resistant food storage business, working with Park and Forest Service Bear experts, for over 20 years as well as an avid camper and backpacker for nearly 60 years (since before i was a teenager). I have personally tested containers many times with both Grizzly and Black Bears and I have encountered Black Bears while both camping and backpacking several times. No Bear has ever gotten any of my food or trash (except during supervised testing).
Craig
