Human/Bear Security Trade-Off

Interesting example:

Back in the 1980s, Yosemite National Park was having a serious problem with bears: They would wander into campgrounds and break into the garbage bins. This put both bears and people at risk. So the Park Service started installing armored garbage cans that were tricky to open -- you had to swing a latch, align two bits of handle, that sort of thing. But it turns out it's actually quite tricky to get the design of these cans just right. Make it too complex and people can't get them open to put away their garbage in the first place. Said one park ranger, "There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists."

It's a tough balance to strike. People are smart, but they're impatient and unwilling to spend a lot of time solving the problem. Bears are dumb, but they're tenacious and are willing to spend hours solving the problem. Given those two constraints, creating a trash can that can both work for people and not work for bears is not easy.

Posted on August 18, 2006 at 7:02 AM • 63 Comments

Comments

TimTheEnchanterAugust 18, 2006 7:42 AM

"There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists."

That is a phrase to savour.

jmcAugust 18, 2006 8:19 AM

Instead of giving bears the right to vote, I'd rather see ppl with the intelligence of bears /not/ voting in the first place. ;)

Ian EiloartAugust 18, 2006 8:19 AM

Isn't the assymetry here the relative reward. The bear clearly has a lot to gain by working out how to get the food.

There's not much perceived benefit to the human, who can take the garbage home, or just dump it. If tourists are taking their garbage home, then that's great. If they're just dumping it instead of bothering to work out how to open the garbage bins, then I say feed them to the bears!

SaxonAugust 18, 2006 8:30 AM

How long before the bears start lurking near the cans, waiting for a human to open one so the bear can "mug" the human and get at the contents (rather like an ATM mugger)? Based on my experiences with the black bears in New England, this would not be beyond a bear's reasoning capacity.

Dom De VittoAugust 18, 2006 8:34 AM

Does anyone else not see the comparison between "people" and terrorists?

Anti-terror security is a trade off between people who want convienience and safety, and terrorists that are willing to devise cunning (and time-consuming) plans to achieve their goal.

Fred F.August 18, 2006 8:36 AM

I don't know what the solution is but I am sure it involves either tagging the bears or tagging the humans. Maybe some face recognition software would work, although there may be some overlap there too.

Maybe the rangers should start taking all food before allowing the tourists in. For their safety of course.

JonAugust 18, 2006 8:43 AM

Good example and quotation, but has anyone been able to find the source? I've seen it as a motd and a sig, but have yet to find the original.

Mike SherwoodAugust 18, 2006 8:45 AM

The party putting stuff into the trash is willing to spend about 10 seconds on the activity, whereas the party getting stuff out has no time limit. In order to cater to the lazy and stupid, someone has to do more work.

The configuration given doesn't work because it has the traditional open and closed configurations, while making the switch between those configurations needlessly complex. In this case, they need a recepticle that fails secure.

A mailbox like solution seems pretty obvious and rational to me. A cylinder with a horizontal axis has to be rotated to a position where it is accessable only from the outside in order to put trash in, then it rolls back to the position where the contents drop into a storage bin. A simple lock on the bin would keep everyone but the trash collector out of the bin, but allow everyone to deposit their trash in a designated location.

However, the trash can design could have been someone's thesis paper to prove that bears are pretty smart and a lot of humans are dumber than paste.

AlanAugust 18, 2006 8:45 AM

Maybe the lack of intelligence is in the Park Service and its vendors. I would think a simple combination lock, with the combination printed next to the lock, would stump a bear. For example, one of those mechanical door locks with six little silver buttons close together, where the person has to press four buttons in the right order then turn a knob, would probably work fine.

Dom De VittoAugust 18, 2006 8:47 AM

How long before the hungry bears start hinding the the trash cans in oder to jump out and eat the tourists?

[ Sorry, I've just been reading the plot of "Snakes on a Plane".... ]

Anyway, why is this news? Has nobody ever heard of 'Yogi Bear' ??? He used to get pick-a-nick baskets all the time, "Mr Park Ranger, sir".

GedAugust 18, 2006 8:47 AM

I think the most efficient way of solving the problem would have been to ban all sorts of liquids in any form of containers in the entire park.

After all, that works for TSA and DHS.

AlanAugust 18, 2006 9:04 AM

I found a page on the web from 1995 that attributed the "smartest bears" quote to Richard Wabrek, who appears to be a professor of engineering at Idaho State University (isu.edu)

GavinAugust 18, 2006 9:08 AM

Mike,

A combo lock has been tried at parks. Within 2 days someone always Jams it open or doesn't re-lock it (depending on which design - all have been tried). You have, in the process, also to design for the jerk human who just wants to break stuff.

You would be surprised how many ideas we at the park service have tried. Maybe think before declaring us stupid?

Kees HuyserAugust 18, 2006 9:40 AM

@ Mike Sherwood
"A mailbox like solution seems pretty obvious and rational to me. A cylinder with a horizontal axis has to be rotated to a position where it is accessable only from the outside in order to put trash in, then it rolls back to the position where the contents drop into a storage bin."

In my neighbourhood in Amsterdam, The Netherlands, we have garbage collection points like this. You open the lid, put your garbage bag in and close the lid. The garbage bag then rolls out of the tray into an underground container.

If you put garbage next to the container, the 'trash police' will collect it and go through the contents to try and find you, then fine you.

There are always a few bags next to the collection point...

I'm for the right to arm bears so they can shoot the littering so-and-so's!

ZachAugust 18, 2006 9:49 AM

Looks like a new research field is opening up: CAPTBHAs (Completely Automated Public Turing Test to tell Bears and Humans Apart)

Grant GouldAugust 18, 2006 9:56 AM

Clearly the solution is to create a mandatory national ID card for bears. The trash can would demand ID from bears, and refuse access to any that presented ID that verified that they are bears.

quincunxAugust 18, 2006 10:11 AM

'Time to give bears the vote.'

'Instead of giving bears the right to vote, I'd rather see ppl with the intelligence of bears /not/ voting in the first place. ;)'

It is precisely that bears are smart that they do not vote.

The solution of the bear/trash problem is obviously the same solution that would prevent poor forest management: privatize it.

Both economics and studies confirm that private owners take care of their properties much better than government caretakers.

The areas with least forest fires and deforestation are privately owned.

Tim SakayevAugust 18, 2006 10:24 AM

"There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists." - that is a phrase of the year, IMHO.

However, aren't we trying to solve wrong problem? I'm quite ignorant in study of bears, and might be wrong, but wouldn't this scenario work only if bears were learning that it is "not worth" going near people, since the food is unreacheable. That is, a bear after few visits to a campground would learn that despite the smell the food still cannot be retrieved, and therefore further attempts are unfeasible, and learn not to react to the smell.
If i'm not mistaking, the bears will still come to campgrounds following the smell. No matter how "bear-proof" the trash can may be, that's not going to stop bears from smelling the food. And since bears cause problem by presence in the campground, it doesn't really matter whether they are there trying to break in, or already going through the trash.

Instead, the solution could include something to supress the odor of the food (again, i don't know how feasible if possible at all this kind of a solution), so that the smell wouldn't attract bears in the first place.


Well, those are my thoughts - nothing more. Any opinions?

JoeAugust 18, 2006 10:24 AM

What about a honey pot (bears, remember?) type of solution? Leave (and maintain) trash areas that are more accessible to bears and prohibit people from going there.

Bruce SchneierAugust 18, 2006 10:33 AM

@ quincunx

Final warning. Please do not turn every post into a hook for a political diatribe. I appreciate that you're here, and I would like you to continue to comment. But the next step is to delete off-topic comments such as this.

Diesel SweetieAugust 18, 2006 11:00 AM

@Martyn:
> Time to give bears the vote.

Down that road lies madness... before you know it, people will demand the right to arm bears, too!

(Yeah, I know, weak pun, but someone had to do it.)

L8ShiftAugust 18, 2006 11:04 AM

bears would want nothing to do with my wife's cooking.. no need for any lock..

I forfeit...to the bears.. :)

Jon BarkerAugust 18, 2006 11:21 AM

"A combo lock has been tried at parks. Within 2 days someone always Jams it open or doesn't re-lock it (depending on which design - all have been tried). You have, in the process, also to design for the jerk human who just wants to break stuff."

Why doesn't this happen with the ones that bears can open?

Do the bears come along and shut them if they can?

AnonymousAugust 18, 2006 11:27 AM

Why not just have a catch that you have to stick your finger in to open? A bear would have to use a twig to acheive the same thing...

Dossy ShiobaraAugust 18, 2006 11:34 AM

"There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists."

"[...] creating a trash can that can both work for people and not work for bears is not easy."

...

I said something very similar to someone the other night who is playing around with a new CAPTCHA implementation. I pointed out that "if you make the CAPTCHA too hard for a computer to solve programmatically, then you'll end up with humans that can't solve it either. As 'dumb' as computers and the current state of AI is, the 'smartest' computer is still smarter than the dumber humans."

ChrisAugust 18, 2006 11:45 AM

"Why not just have a catch that you have to stick your finger in to open? A bear would have to use a twig to acheive the same thing..."

I think this fails the "jerk human" test. What's to stop someone from jamming the catch or more likely placing something unpleasant into it?

Seems the most robust candidate solution I've seen here is the mailbox-style drop off. It seems that such a device could be made remarkably jerk-resistant with little effort. Such a solution would require timely collection of the refuse to prevent the bin from overflowing but otherwise seems sound.

another_bruceAugust 18, 2006 12:32 PM

palm readers. a human hand placed on the plate opens the container automatically, no go for a bear paw. simple enough for human resources people to operate.

AnonymousAugust 18, 2006 12:39 PM

"Why not just have a catch that you have to stick your finger in to open? A bear would have to use a twig to acheive the same thing..."

"What's to stop someone from jamming the catch or more likely placing something unpleasant into it?"

This is the system used across all the parks in Canada and I have never had a problem with sticking my fingers into something unpleasant. The campgrounds with the least bear problems are the ones with the most aggressive waste managment programs. For example the ones that pick up all the garbage 2 or 3 times a day. It is a little expensive to do it, but it really cuts down on the bear problems.

BrendanAugust 18, 2006 12:53 PM

The mailbox *is* the right solution, precisely because it solves the same problem.

Mailboxes are the way they are to:
1) provide public drop-off points for everyones mail, while
2) maintaining security to prevent spies/thieves/delinquents from access that mail

You just have a different thief going after tastier mail. The two services have almost identical requirements for ease-of-use and difficulty-of-tampering, so it's no coincidence they have similar solutions.

BrianAugust 18, 2006 1:14 PM

Vaporization chambers. Trash goes in... a small pile of ashes comes out.

Also handy for body disposal.

AnonymousAugust 18, 2006 1:15 PM

if you want to talk about cleaning up the parks, it's too bad pollution from the old petroleum fired two-stroke engines are killing the rangers and the bears. now that's a harmful trade-off.

aikimarkAugust 18, 2006 1:44 PM

Whatever you do, don't tell Stephen Colbert how persistent bears are. He's already deathly afraid of bears. ;-)

RichAugust 18, 2006 2:02 PM

Keep in mind that like people, bears come in various varieties. Black bears have poop with red berries in it.

Grizzley bears on the other hand- well, you know those bells that hikers wear to keep away bears...

The other way to tell them apart is to climb a tree. A black bear will climb up after you. A grizley will rip the tree down.

AndrewAugust 18, 2006 2:12 PM

To me, the problem is failure to put enough eyeballs on the issue. We have several viable solutions in this list -- and if the Forest Service would solicit ideas as effectively as your blog, they'd have an answer much easier and cheaper.

I see this as a powerful argument for open-source security design. A good design doesn't depend on obscurity anyway . . .

HansAugust 18, 2006 2:52 PM

"To me, the problem is failure to put enough eyeballs on the issue. We have several viable solutions in this list -- and if the Forest Service would solicit ideas as effectively as your blog, they'd have an answer much easier and cheaper..."

The only viable solution anywhere on this page is the one that they've already been using for the past couple of decades. The rest sound like what one would expect from a bunch of armchair engineers that have exactly zero experience in dealing with dumpsters and bears. Pushbutton combination locks, image recognition, vaporization chambers, etc... wouldn't even pass a trial test, assuming they didn't kill someone first.

JimAugust 18, 2006 2:53 PM

What about a simple combination lock -- maybe a mechanical keypad with 6 digits, and a 3-digit combination -- and a printed sign that clearly states the combination?

Bears can't read no matter how long they try, but people can still open it very quickly and won't lose patience.

Can a bear brute-force a lock and then memorize the correct combination? Seems unlikely.

--jim

BrendanAugust 18, 2006 3:33 PM

Jim,

It's not just a question of the intteligence of bears. If the user can do something to make the process marginally easier on themselves (i.e. leave it unlocked, or block it open) then they probably will.

sidelobeAugust 18, 2006 3:38 PM

Airline passengers are the "park tourists", and the terrorists are the "bears".

Clive RobinsonAugust 19, 2006 8:06 AM

Although not as dangerous as bears-humans, in the UK there is a similar battle going on that so far shows that humans can be out witted by animals with very small brains.

The North American Grey Squirrel was introduced into the Uk several decads ago and has quickly eradicated the native red squirrel in any area it has chosen to inhabit (ie most of the UK mainland). Whilst Red squirrels are (supposedly) cute Grey Squirrels are regarded as vermin (tree rats).

A very large number of people in the UK like the birds that land in their gardens and try to encorage them by putting out food for them. However the squirrels think that they are more entitled to this food than the birds.

So there is an on going battle where the humans ,try to design a Bird Feeder that is squirrel proof, as far as I am aware nobody has yet come up with a (cost effective) design that defets squirels whilst still alowing the birds to feed...

I guess it is the UK modern equivelent of the "Better mouse trap".

NAugust 19, 2006 9:27 AM

My grandpa built a working squirrel-proof birder feeder, but it has to be placed away from trees.

You put the feeder on top of a pole with an inverted dish underneath it (he used the lid from a charcoal grill).

Even if the squirrels can climb the pole, they can't get around the lid. The only way to get to the top is to jump onto it from above.

MikePAugust 20, 2006 9:31 AM

N's grandfather's design works fairly well - my parents have a very large population of squirrels and birds. The birds sit in the feeder and drop the hulls, the squirrels scavenge the hulls for anything that's left. Everybody's happy, including the cats. As you say though, can't have any trees close by, or anything else from which the squirrels can leap... squirrels sometimes run along the house power lines and jump into the feeder, but it's difficult enough that it doesn't seem to be a problem.

Their biggest problem is the jays and magpies chase away the smaller birds.

As far as the bears go, most campgrounds at which I've been have a central dropoff point that gets emptied on a regular basis, but there's nothing special, just a heavy lid on a dumpster. Problems start when people don't drop garbage off there though, I imagine. I was trained as a child to always dispose of garbage at night, or any time the small bag got full, but I guess expecting that level of discipline from everybody might be a bit much.

guestAugust 21, 2006 2:16 AM

Growing up in Alaska, I think this problem is unsolvable, basically because when a 800 pound bear, comes and eats your garbage. You don't dare to try and stop him.

OldWorldBlueEyeAugust 21, 2006 3:17 AM

Put all visitors to pay 500 $ deposit (or progressively based on yearly income?) and list all carbage-producing stuff before entering park. Deposit ID is required and must be shown then asked to rangers. If visitors can show that they brought back all garbage, deposit is paid pack other wise used to "Bear Safe - Human Easy" garbage can development program.

DeathwindAugust 21, 2006 7:28 AM

No problem has ever resisted the application of a high-yield thermonuclear bomb : so I'd say nuke the bears ! ;-)

More seriously, Bruce as (almost) always has a point.

The similarity between this case and the current situation with airline traffic is uncanny.

The "solution" to a problem just makes life intolerable for the most part of humanity.

jayhAugust 21, 2006 9:22 AM

My brother tried to put up a squirrel proof feeder but twice it was thoroughly destroyed by bears

EoinRAugust 21, 2006 10:30 AM

Thanks for such an entertaining read!

My suggestion to the problem would be to try and generate peoples interest in their rubbish.

I haven't been to Yosemite before but would guess that there must be some sort of a 'centre' with buildings of some description.

What if there was a permanent exhibit describing the problem of bears and rubbish - since it's been highlighted here, its fun to laugh at ourselves and how stupid mankind can be. A few accompanying bins of various designs that would encourage visitors to test the bins (and put their rubbish in, in the process) and rate their own intellegence against the bears! A final suggestion would be to get people to design their own bin - no matter how whacky their idea, it will at least be getting people to focus on the problem of how to dispose of rubbish. And you never know, maybe somebody might just come up with the best solution in the process.

TomBAugust 21, 2006 11:29 AM

Yosemite used to have an open dump. With bear feeding. I am sure there is plenty of film, and you could cut in a few shots of bears breaking into cars.

For a lighter look at the issue, I highly recommend Phil Frank's book Fur and Loafing in Yosemite.

real worldAugust 28, 2006 2:05 AM

why not try some negitive reinforcement like a mild electrical shocks given by a ranger or vol when bears investigate a trash can ? perhaps a dose of noise at a frequency that humans can't detect. lLets think outside the box campers.

David Chaplin-LoebellSeptember 7, 2006 10:35 AM

These days, hikers in most places with bears are asked to carry "Bear-Resistant Food Canisters" which are basically containers that (according to the park ranger I chatted with) can't be opened without the use of an opposable thumb. In general you want to carry your trash out with you, not leave it in a trash can in bear country.

http://www.wcs.org/international/northamerica/...

I see from a quick web search that these are required at Yosemite also:

http://www.nps.gov/archive/yose/wilderness/...

I just got back from the Adirondacks, in New York, where I took a short day hike on Mount Marcy. There used to be a cable over the creek by Marcy Dam-- where food could be hung, in bags, on a long cable over a wide creek. This has been removed, and there are some amazing photographs at the trailhead of bears climbing out on these cables, dangling over the creek, and retrieving the food from bags. Unfortunately I can't find these photos on the web anywhere... they're a testament to the ingenuity of bears.

Jeff LanamSeptember 8, 2006 7:03 PM

Geez, don't you people go to national parks? At the ones I've been to the trash containers have a very simple latch that requires you to stick your hand about two inches in and push a lever. It's too small for a bear and too heavy for a racoon. The problem isn't that people can't use it, it's that they won't!

BearSaverNovember 10, 2006 12:44 PM

Folks, there is a full line of tested, field-proven, user-friendly bear-resistant trash containers of all sizes and for all applications available through Bearsaver - see bearsaver.com website. This company supplies bear-resistant trash cans to national parks and national forests throughout the US via a GSA contract.

Nicholas CarboneFebruary 20, 2008 5:37 PM

I have a 3/4 of a acker residental Area and continue to have someone taking the fruits off of my trees. I want to know what is available.

example
Trip wire with tear gas, Trip wire with electric shock just like the police use, or anything else you can suggest.

This has been going on for two years and has to stop. They wait until the fruits are just about ready to pick and take them all.

Nick

David HarmonJanuary 4, 2011 6:25 AM

Nicholas Carbone: A shotgun loaded with rock salt, and a camouflaged tent. ;-)

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