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June 24, 2009 6:12 AM   Subscribe

The training of and science behind SAR dogs is a quite interesting and well developed field...

Some dogs, like this one, use the airscenting techniqueto find any living human scent within a search grid. These dogs generally operate off lead, covering a wide search area in a short period of time. These dogs do not generally require a scent article (caution PDF) from the missing person. (However, discerning airscent dogs do exist.)

Airscenting dogs run quickly, with their heads in the air, working back and forth as directed, trying to find the scent cone. As you can visualize, a scent cone is a triangular shaped field of scent dissapation that spreads out along the wind and water from the source of an odor, in this case the human. Once the canine realises she is inside the cone, she works frantically back and forth, pushing forward, as the cone gets narrower and narrower, eventually winding up at the point of origin.

Obviously, issues arise when sudden wind shifts, extreme weather, and elevation change occour within the search grid.

They may operate as far as 1-2 acres ahead of their handler. Some even wear loud field bells. Once they find their subject, they generally let the person know they've been seen, and return to their handler and perform an alert. Like any detection dog, this can be a passive alert or an active alert. The point is that the handler knows, without question, that the dog has found something. "Show me!" and the dog leads the way back to the subject.

Other dogs are tracking or trailing dogs. These dogs operate on-lead, and are generally quite excited and insane, often yelping, barking, and pooing frequently along the trail. This particular video shows a young dog in the "runaway" stage of training, where the dog physically watches someone run away.

Tracking dogs move quickly too, dragging their handler down the exact path taken by their subject. In many cases, dogs have custom, hand-tooled harnesses for maximum comfort and safety. Unlike airscenting dogs, they detect the decay of skin rafts left by the subject. These dogs generally require a scent article and a point of origin, however a well trained dog will find the track of the offered scent within a couple acres fairly quickly. The dog instinctively follows the scent in the correct direction, detecting minute changes in the age of scent to detect direction of travel. Some dogs, like Bloodhounds , have been specifically bred so that their physiology makes them more adept at their scenting role. You can see the flaps around his mouth, and imagine how they capture scent and direct that scent to the nasal passage. I can't readily find the source outside of the book below, but a bloodhound can have up to 400 million scent receptors, compared to the measly 5 million present in the best human nose. A typical German Shepherd will have approximately 220 million. There is some evidence which suggests that dogs with darker noses have better scenting capacity, but the research is inconclusive.

Cadaver dogs can operate on land or water. These are dogs specifically trained to discover decaying human remains. While it sounds macabre, too many times a missing subject becomes a cadaver search, and families and authorities appreciate having the remains. Cadaver dogs are also used in law enforcement to detect and uncover the bodies of missing persons and murder victims who might have been burned, buried, or otherwise hidden. Interestingly, and perhaps counterintuitively, cadaver dogs are often trained with an active alert, which might involve digging. Mouthing is specifically forbidden, however.

What makes a dogs scenting skill remarkable isn't the volume of smell detected, but rather the ability to discern the individual elements of the odors percieved. This is why a skilled tracking dog will follow 1 trail from a room with dozens of people inside.

Want to learn more? The most widely accepted and generally acknowledged work in this field is "Scent and the Scenting Dog", by William G. Syrotuck. Alternatively, you can follow the link in the post title to visit NASAR and find a group near you.

This is my first post to the blue, and I apologize for its length. Maybe next time I'll discuss operational command and the role of the Incident Commander, mapping, the ideal search environment, and the motivation of the dogs in question.
posted by TomMelee (32 comments total) 49 users marked this as a favorite

 
just in time for take your pet to work week!
posted by snofoam at 6:46 AM on June 24, 2009


I've been in those scent cones before. Sometimes they are hard to avoid. Especially on the subway.
posted by digsrus at 6:54 AM on June 24, 2009 [1 favorite]


Awesome post - as previewed in this AskMe thread
posted by Jofus at 7:03 AM on June 24, 2009


yes, excellent post, great reading - thanks much

TomMelee, i'm going to quote your comment from that other thread because i found this a vivid image of airscenting:

... for example, my border collie was an air-scenter. Meaning that she found all living humans w/i the search grid, she did not key on a scent article. It's used when you don't have a specific point of last origin AND the search area isn't too contaminated. Or...when you've got hundreds of acres to cover fast. Anyway, as she searched for the scent cone, she'd often stand on her hind legs, spinning in circles, trying to find the human scent as it wafted from wherever.

posted by jammy at 7:14 AM on June 24, 2009 [1 favorite]


I'm so glad you decided to take your terrific comment and flesh it out into a post, thanks TomMelee.
posted by jessamyn at 7:16 AM on June 24, 2009


Heh, thanks. I was afraid I was totally derailing in that other post. I'd happily post pictures of my dogs working...but that seemed a little...eh...borderline.
posted by TomMelee at 7:18 AM on June 24, 2009


My wife trains hunting dogs, primarily pointing breeds. Next month our Viszla is taking his Navhda Natural Ability test.

I've worked with hunting dogs when I was a kid - mostly retrievers used for duck hunting. The drive that those dogs exhibit is amazing. Now that I watch pointers work, I am no less amazed.

Generally, the dogs work a field at a full run. You can tell when they have caught wind of a bird though, because they usually turn hard back onto it as they leave the scent cone. Then it's nose down back and forth until they get close enough to point. It's just amazing to watch.
posted by Pogo_Fuzzybutt at 7:23 AM on June 24, 2009


Great post! And yes, definitely post photos of your dogs!
posted by orrnyereg at 7:24 AM on June 24, 2009


Borderline .. collie?

Thanks for the volumes of detail, very interesting stuff.
posted by filthy light thief at 7:27 AM on June 24, 2009


Yes, this is an awesome post. Seeing that "excited and insane" link above makes me go all snoogie-woogums. "Aww! Who's a good boy? You are! You're a good boy! You're a good boy who can track fleeing criminals with uncanny accuracy!"
posted by JHarris at 7:33 AM on June 24, 2009 [3 favorites]


Mouthing is specifically forbidden, however

"No ma'am, those bite marks were there when we found him."
posted by scrutiny at 7:46 AM on June 24, 2009 [1 favorite]


I drive by the Search Dog Foundation headquarters a couple of times a week.

Was there a post where some guy was discredited for lying about his dog's ability to track criminals recently? Can't remember where I saw it.
posted by Xoebe at 8:15 AM on June 24, 2009


You know, we have this rule in SAR: "Trust the dog."

Once my dad hid for me as part of a search demo. He specifically disregarded my instructions about where I wanted him to go. Tracking him along, my goldie veered off the path (on his trail). I kept trying to tug her back, but then finally gave up and went with it. She brought me right to his feet.

Re: that article, tracking isn't like a DNA test. It's not cut and dry. Moisture at ground level, wind speed, temperature, other people on the trail, fatigue...all issues that can mess with a track.

That said, the most talented dog I've ever seen was a black lab named Axel. His bloodline is well-enough known that the airforce gets first-dibs on his pups. Anyway, I once watched Axel track a 48-hour old track across a couple miles of asphalt in the summertime. Ran it full speed, never even slowed down.
posted by TomMelee at 8:27 AM on June 24, 2009 [3 favorites]


TomMelee: Cadaver dogs can operate on land or water. These are dogs specifically trained to discover decaying human remains. While it sounds macabre, too many times a missing subject becomes a cadaver search, and families and authorities appreciate having the remains. Cadaver dogs are also used in law enforcement to detect and uncover the bodies of missing persons and murder victims who might have been burned, buried, or otherwise hidden. Interestingly, and perhaps counterintuitively, cadaver dogs are often trained with an active alert, which might involve digging. Mouthing is specifically forbidden, however.

As seen on TV.
posted by paisley henosis at 8:33 AM on June 24, 2009


Awesome, awesome post TomMelee, thanks. My wife and I just got an aussie mix pup and are training her as an air scent dog here in Seattle. They are truly remarkable animals and watching the "light bulb" moments where they make a connection is really rewarding. She's at the runaway stage at the moment and just loves to work.

Looking forward to hearing more about the SAR work you're doing. What part of the country are you in?
posted by Pantengliopoli at 9:00 AM on June 24, 2009


Fantastic post. Really interesting about the bloodline thing - I know the Royal Australian Engineers always get 'mutts' as their EOD dogs - the stupider the better as the saying goes. I think (don't quote me) that the Army police go for 'proper' breeds though.
posted by Megami at 9:12 AM on June 24, 2009


This is a great post.

Besides hounds, what other dogs are potentially suited for SAR?
posted by canine epigram at 10:11 AM on June 24, 2009


... and the training and development of SAR robots (Robin Murphy doing great stuff at TAM) has had some bumps as it matures and the field in general could learn a lot about human:agent coordination(128KB IEEE pdf) from the richness and diversity of human:canine joint activity .
posted by oldefortran at 10:24 AM on June 24, 2009


I'm in Appalachia. For full disclosure, I haven't done much other than support for the last couple years. I have 3 dogs...1 border collie mutt and 1 golden, who grew up together and ran together. I installed this sweet platform above the wheel wells in my 94 isuzu trooper so I could get 2 fullsize crates in there, with storage underneath. If one dog went, both dogs went.

The border is my airscenter. She's a flipping genius. I actually got her at 5 weeks old as an abandoned puppy, about 8 weeks after my Redbone had died of a seizure following a search demo. My golden is the tracker. She's about as dumb as a stick, but she lives and breathes for balls, kongs, and sticks, and she's got a pretty good sniffer, so she made a great tracking dog. However, we discovered young that she had terrible hips (another rescue), and she was forced to retire young because of the carting-like pressure that tracking leads put on their hips. She and the border are straight up where-the-red-fern-grows close, and it simply wasn't going to happen to take the border out and leave the golden. I still have to hide her harness from her, she sees it and flips out. So anyway, I let them both retire, and now we just play hide and seek as a fun distraction.

My third dog is also kind of a rescue, he's an Epagneul Bleu de Picardie. He's a little old to start search, however we do some intensive obedience and such with him. The past couple weeks he's been commissioned as "Chief Groundhog Exterminator", a job he tackles with relish. (Ketchup too, probably.) (I can smell the memails now about my killer dog...)

The thing about search is that any dog can do it. I mean, I wouldn't recommend a toy breed, but I've seen GSD's and Malinois', Newfoundlands, European and American Labs, Chesapeake Bay Retrievers, collies (ok, that one wasn't impressive), Border Collies, really any dog big enough to go through brush and motivated by praise, balls, or food, or all of the above. (I don't like food though, such a hassle. Ball-dogs are the best!) Lots of bird dog breeds are sight hounds, which doesn't mean that they won't sniff, it just means they're developed to use eyes first and nose second.

There's nothing that says a purebreed is any better, really lots of purebreds come from a show lineage instead of a working lineage, and that means they're for looks more than utility....i.e. their noses might have suffered. Lots of folks pick out their new scent dog by finding the most active, intelligent, and playful dog in the litter. Crazy is good, because energy=motivation.

I talk too much.
posted by TomMelee at 10:39 AM on June 24, 2009 [4 favorites]


I have a Presa Canario, which is a guard dog breed, who wants a job so badly. I've been thinking about looking into hunting training. The link to NAVHDA might be a good place to start. I know know nothing about hunting and he's probably too big and slow to be any good but I think the training would be good for him.
posted by shoesietart at 11:49 AM on June 24, 2009


Lots of folks pick out their new scent dog by finding the most active, intelligent, and playful dog in the litter. Crazy is good, because energy=motivation.

This is part of the reason behind the dogs I was talking about. 'Take a ball to the pound' - they are usually chosen as not fully grown, not little puppies. Why stupid dogs? Stupid dogs are energetic and they don't question - they will fetch that ball until they fall over. Not sure that is what you want in SAR dogs, but it works well for bomb disposal/EOD dogs.

Mine finding dogs on the other hand are more passive - they are trained to point once they have detected. They are more 'pointers' (in the broad sense, rather than the specific breed) whereas the EOD dogs are 'retrievers'.
posted by Megami at 11:56 AM on June 24, 2009 [1 favorite]


TomMelee: I talk too much.

No, you don't. It's obvious you have a love for these dogs and the art and science of tracking, and hearing about it is fascinating for us mundanes.
posted by Evilspork at 1:15 PM on June 24, 2009 [2 favorites]


Yes yes, seconding Evilspork. This is all wonderful!
posted by JHarris at 1:25 PM on June 24, 2009


Yeah, this info is riveting. Thanks!
posted by cybercoitus interruptus at 2:33 PM on June 24, 2009


SO fascinating, thanks for the post! I have a weird mutt mix: she's part Dachshund, part Beagle, and some Springer Spaniel. She's the sniffingest dog I've ever seen, and I've considered training her for this kind of work. But being a rescue, she's very wary of new people, so I don't think she could do it "professionally." Still, it would be fun to see her track something. If we didn't live in the 'burbs I think she'd be a hunting dog.
posted by TochterAusElysium at 3:15 PM on June 24, 2009


Excellent first post. Way to go.
posted by GatorDavid at 3:57 PM on June 24, 2009


I saw an avalanche rescue dog demo once as part of an avalanche school that I attended. Friggin' amazing. Here is a short video shot at Berthoud Pass, CO that is similar to what I saw. linky
posted by fieldtrip at 6:49 PM on June 24, 2009


Why do they train cadaver dogs to do an active alert?

And nth -ing: great post!
posted by txvtchick at 8:08 PM on June 24, 2009


Agree with all the compliments! I guess it would be redundant to have an fpp sidebarred. I know it is usually considered bad form to comment a lot in your own thread, but this is an excellent example of how it sometimes works out well. I look forward to learning a lot about scent dogs tomorrow! Good night, all.
posted by TedW at 8:43 PM on June 24, 2009


TomMelee, I'm not a "dog person" and I dont have a dog but this is a wonderful post and a really really fascinating subject. keep it coming, please!
posted by supermedusa at 9:17 PM on June 24, 2009


A lot of my former team members now run a FEMA team instead of a wilderness team. I'll see if I can put together some info on that. Disaster dogs are truly amazing...but I'd never run disaster with my own dog, as the mortality rate is just too high. They do this walking drill though, where the dog looks almost like a chameleon, because they test the ground in front of them for stability a couple times before stepping, and then they only put their back feet in the exact places where their front feet stood.

For real, they leave two footprints.

There's another great apparatus that is 2x2's on end in a row about 2 feet wide by 10 feet long, and they're all different heights, about 6 inches apart. The dogs must traverse it. Really amazing to watch.
posted by TomMelee at 6:39 AM on June 25, 2009 [2 favorites]


i find this really interesting. yay thread!
posted by rmd1023 at 4:07 PM on June 25, 2009


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