Do dogs understand barks?

This habituation study shows that the dogs can tell the difference between the barks. It does not show that the dogs have a different response to the two kinds of barks (let along attribute different "meaning" ... doggie meaning that is ... to the two barks).

Please note that barking is a recent innovation in these wolfian subspecies. Almost all breeds of domestic dogs bark, but other canids do not. It seems to be an effect of domestication. Given that canids evolved for tens of millions of years with strong olfactory signalling, any consideration of somehting novel like barking really is probably best understood in that context.

Your dog smells the over the fence dog. All the time. The change in smell tells your dog on a minute by minute basis some combination of where that other dog is, what it is doing, what it's affective state is, and which way the wind is blowing. The TV dog does not exist in your dog's world because it can't be smelled. The fact that the TV barks now and then is odd.

This does not mean that a dog (or cat) can't occasionally react to at TV image of a dog (or cat, or prey item) with sound, etc. as though that thing was real. These large brained organisms (mammals) are complex. But asking questions about what dogs react to (what they are "thinking") outside the context of olfaction is like the audience at American Idol who is the best performer based on the direction of the breezes in the auditorium, and ignoring the fact that the performance is mainly auditory and visual.

Greg: Our dog barks only in response to a bark from the other dog. So it is pretty clear she is responding to the other dog's bark, but I agree with you that the only thing this experiment seems to show is that barks can be differentiated. I didn't know the evolutionary aspect of barking, which is pretty interesting. Thanks.

You obviously know a lot about this. Good, Greg, good greg. Stay!

Greg - A very thoughtful comment. I especially appreciate the analogy at the end.

I have often wondered myself about animals and communication. Your analogy brings up an interesting point. We tend to assume that if a dog is barking that the the primary mode of communication will be auditory, when that may not be the case.

I once heard that cats only meow as an attempt to communicate with humans, not each other. I have no way of verifying this - could be an urban legend for all I know - but it's an interesting thought nontheless.

My cats don't meow at each other, but they do meow at people, especially me. The one I talked to most as a kitten meows all the time. They meow more at people they know than at strangers.

However, kittens and mothers meow to communicate with each other. My mostly silent cat meowed almost continuously when she was in heat.

My cats occasionally make noises when communicating to each other, but usually only in the "this fight has gone from play to real" transition, and it's accompanied by body language and probably scent changes.

http://www.modernpooch.com/archives/FarSideDogCartoon.jpg

I agree that the study seems to indicate that the dogs can tell one bark from another, not necessarily that they can identify a warning bark as opposed to some other type of bark. In other words, it is the novelty that they responded to. Although my expertise is limited to observing my own dogs closely for many years, I think Greg is right about the dog world - it is a different world from ours. Their ability to detect odors is amazing. I have often wondered what it must be like.

But, on the other hand, I would not be surprised to learn that a dog can tell a warning bark from some other types of barks. I have no doubt that a dog would recognize other types of dog sounds, like a puppy whimpering or an aggressive dog growling.

Cats use a rising trill as a "anybody here?" call, and a two note hi-low as a response. I've noticed this for decades.

Once I was home alone upstairs and heard the clunk of our cat door as one of the cats -- we had several at the time -- came in. I heard its "prrrRT" and replied with the appropriate "PR-rr" noise.

Then I heard the cat come through the house and up the stairs making a little "prrt" on each step. He came into the bedroom. Turned out this was a young cat -- one of a pair of kittens the household had taken in off the street that season.

He looked around, ignoring me sitting on the bed reading, and he went "prrrRRT" again. Silence. He looked around again, then went over and looked behind each piece of furniture, then looked all around again, went over and into the closet and poked around, came out, went under the bed and back out, went back looking behind the furniture, slowly moving faster and faster.

Then he stopped, looked around, and started to trot straight toward the door. Just as he got into the door, he froze with one foot in the air and slowly looked over his shoulder and, for the first time, raised his eyes and looked at me.

I went "PR-rr."

He ran back, threw himself up onto the bed and onto me, purring like mad. After that he was 'my cat' and he stayed with me the rest of his life, a good 23 years.

I dunno, ya think cats use sound?

Maybe it's just me.

No, seriously, listen for those two "hello" and "here I am" noises. You'll hear them from cats, both to other cats and, once you learn the appropriate response, they'll use them to call you too.

They work the other way too. I can do the "prRRTT?" and get back the "PRrr" reliably in our house and any house I recall visiting with cats.

This is a little different from the experiment you describe, but perhaps related:

My Pekingese used to bark and snarl furiously at six or eight assorted good-sized dogs in one yard along our walking route.

The dogs behind the fence would fall over themselves to get in my dog's face,just two or three inches away, barking and growling. It was a long yard, and the dogs would keep this up for the entire time it took me to walk my Peke past them. One day, however, as the dog pack inside the yard followed us along the fence they came to a gate that had been left open, and they all spilled out into the road. For a moment, I was terrified, surrounded by all the noise and activity. But then the dogs, my Peke included, seemed to suddenly realize what had happened, and there was total silence.

The yard dogs slunk back inside the fence, and as my Peke and I moved on past the gate, the yard dogs followed, and with the fence safely between us again, they all returned to barking and snarling at each other.

My Peke had previously attacked both a huge husky and a big Chow, so I'm not thinking it was fear that silenced her. And certainly the pack of large dogs had nothing to fear from me or my Peke. It looked to me rather like they all understood that the barking had been fake, a bit of entertainment, and nobody was holding any grudges. It was interesting to me that every dog, mine included, seemed to have the same understanding about the meaning of all that barking and the meaning of the silence as well.

A couple of years ago I saw a report of some research to see if people could interpret dogs' barks (sorry, I don't have a link). They used a breed that barks a lot, recording it in various situations ('let's play', 'I want food', 'keep away' and so on). Both dog owners and non-dog owners did significantly better than chance in identifying the situations. Presumably if people can, dogs can too.

I have 3 dogs, all of them street dogs, picked up off the streets of Taipei between the ages of 6-9 months. Mongrels all.

The oldest one happens to be the brightest one, and is the leader. She understands up to 20 phrases in mandarin, or about 50 words, but her english ain't too great. She barks commands at her human masters, and generally does not bark at other dogs. Basically, "it's time to go, WTF is taking you so long", or if the doorbell rings, she barks to confirm "someone is coming", and there is another bark when she barks to tell those shooting off firecrackers during the Lunar New Year holidays "Enough already, STFU". Other than that, she uses non-verbal communication, like looking at you, and then looking at the kitchen, meaning, "give me something to eat". If her tail is down, she is not comfortable, if it is up and wagging, all is well. All 3 barks are distinguishable to me, but then again, since I hear the doorbell and firecrackers, maybe it's my imagination.

Our youngest dog is the dumbest. She barks when she is anxious, when she wants us to know someobody is coming, and at any other dog on the street in an agressive tone that says, "get off my turf you SOB". Any size dog she will bark at, no matter the size, and if not on a leash, she will take off after the dog, and if the dog does not back off, she then reverses course and seeks a safe haven. She is not a fighter. The smallest of dogs, if thats what they are, she ignores, she will not bark at them, recognizing they are mindless creatures who do not know she could crush them if she so desired, and her thrill lies in the chase, not the effort required to snap their neck. Since they are too dumb to run, no point in wasting calories barking, let alone biting them. Her words, not mine. Her barks are distinguishable, especially the anxious bark and someone is coming bark, vs the agressive bark.

The middle one is male. In his youngest days he was a renowned streetfighter, and drew blood against any dog unfortunate to meet up with him. If off the leash and on the street, he would not bark at dogs he met, he just gave chase, and if anyone dared clash with him by not running away, it was just growling between bites. Obviously, we kept him on a leash most of the time, but in an urban environment, with 3 dogs, and many street dogs roaming off a leash, and my wife of 95 lbs walking them, as I travel a lot, it's tough to do so. Today, he is older, and generally inclined to look the other way and pretend not to notice other dogs, but our younger dog makes this difficult, so if the younger one charges a dog that does not back off, this one ends up taking on the opponent as the younger one had veered off, and there is no barking. His barks then were more out of frustration when he saw a dog, or heard a trash car, both of which he wanted to fight, but was prevented from doing so by the leash. He also barks to let us know when someone is coming. All his barks sound alike.

The older female, as indicated, is the only one who does not treat other dogs as the enemy. She does not bark at them at all. Her interactions involve more sniffing and tail wagging than anything else. If the other dogs tail does not wag, and it is pointed up, she walks away, seeing it as an agressive stance. If it does not wag and is pointed down, she stands her ground but does not approach, perhaps thinking the dog is unsure of her intentions or is sick. If it wags back, then it becomes a bit of a sniffing contest between the 2, and if they both passs the others sniff test and visual inspection, they may play around a little. But the arthritis and a heart problem have limited this kind of interaction of late.

I think the bark then is not a language in itself, but is one component of a language made up of verbal (bark or whine, growl), tail movement/position and smells (fear, phermones, etc), and some visual inputs. Taken together, the dog communicates with other dogs. Since we don't have access to the smell component, we must guess, but between the eyes, tail, nose (dry or not) you can tell a lot. After all, a dogs life is rather simple, eat, sleep, relieve themsleves, take a couple of walks. The tricky part comes later on in life when the health deteriorates, and trying to figure out what is ailing them, and hoping your vet knows what he is doing when you figure out it's more than just a bad day for the dog.

I once entered my brother's yard by the side gate, when one of his dogs saw me and emitted a single bark, at which the other dog - an excitable miniature pinscher - came around the house and ran up to me without a sound and proceeded to be petted.

I've always wondered what that single bark was. Could it have been my name?

JuliaL,

That reminds me of a dog that used to snarl, bark, and lunge at me daily, when I rode a bicycle past its house. The dog was tied to a stake and posed no actual threat, until one day, lunging, he broke the leash and came charging toward me. Certain of an attack, I speeded up, but the dog came to an abrupt halt before reaching the road, stopped barking and snarling, walked back to his broken leash and sniffed the frayed end. He seemed completely nonplussed by the sudden change in routine.

It would be interesting to see this done with an even wider range of breeds. Years of working in training centers and vet's offices have given me a lot of time observing dogs.

Just as certain breeds bark more than others, some breeds have a wider range of vocalizations in general. Many spitz family dogs have a very broad range of sounds they'll make for example. Even within this group, some add more barking while others rarely if ever vocalize with a bark, even though they "talk" quite a lot.

My own dogs have different reactions to the barks of the dogs down the street depending on the "tone of voice." They certainly aren't seeing body language when it's happening. My dogs are usually in the house while the other dogs are across our back yard, a parking lot, past a business and on the other side of a house. We have no windows on that side of our place either. I suppose scent could be part of it but I don't think so. I'll have to see about paying attention to the wind now.

When I would get down on all fours and start play behaviors with my dogs as though I were a dog, they would respond as though I were a dog who wanted to play, but I always got the impression they were humoring me and not really taking me seriously.

However, when I would bark, they always seemed non-plussed. I don't think I mastered the syntax!

They did understand the start reflex - when I would, on all-fours, look out the window and suddenly "start" without any vocalization, like I'd seen something of interest, you could guarantee they would both come trotting over.

My favorite was "dog alert". When we were out in the car and I would see a dog, I would say, in normal conversational tone, "Dog alert!" and they would both get up to check out the dog I'd seen. Not that they understood the words, per se.

These behaviors are entirely expected from social organisms of the level of dogs.

All of this was great fun, but none of it tells us if a specific bark carries a specific meaning. I suspect that it really doesn't, but rather carries a tone. Dogs respond very well to tone - if you say something nice in a harsh tone, they appear unnerved by it, and something nasty in a sweet tone makes them wag their tails.

Dogs and their wild relatives have no need for a real vocabulary. A few recognizable tones is all they seem to require. Why would evolution provide more than is necessary?

As a lifetime dog owner, I am most amused that there is even a question of whether dogs can differentiate among the various kinds of barks. As someone above said, if humans can, then dogs can. It doesn't matter that it's a recent development, nor that hearing is not their primary mode of communication; hearing is still an important sense, and they use it.

My older dog (he's 10) has over time developed this kind of vocalization that sounds like he's mimicking human speech. He'll do it in response to a question posed to him. It's a mixture of growl, whine, grunt, and yawning sound, but if he wants you to do something it has more syllables and more of a human whine sound to it.

I have two standard poodles. They are big dogs. A few years ago I headed straight for the tub after spending the day in the front garden. I had no sooner sat down in the bath when the front door opened. (I had neglected to lock it.) My dogs, asleep in the front room went ballistic. They barked in a way I haven't heard used before or, since. I knew what the bark meant, they knew what the bark meant and trust me, the man entering the house knew what it meant. Instead of a short clipped warning bark it was more of a deep-chested 'hold still I'm gonna' rip your throat out' bark. Whoever the invader was he left in a great hurry.
What I suspect has happened is dogs have listened to us talk for thousands of years. They obviously cannot speak, nor do they have much of a grasp of what is being said. What they do know is people talk to each other all the time. When they do, other people listen. Dogs have since learned if you want to be listened to then make noise. I can hear the differences between, I need to go out, the food bowl is empty, I want to go for a car ride and, mister you are about to be road kill. The training is self-taught not taught by mother dog. Once they get your attention, they remember the bark inflection. In essence, they have trained you to speak dog.

I love the idea of dogs actually understanding each other's barks as a language. I think more experiments have to be done in order to draw better conclusions.

I know what you mean Shannon, I know my dogs' barks and when someone is in the house who they think shouldn't be, the vocalizations are very different than when they are barking at a rabbit in the front yard.
Our Greater Swiss has an extremely wide range of vocalizations, yodels to barks to a kind of barooooo that freaks every dog in the 'hood out big time. He only uses that when he is in guarding mode like when the UPS man shows up. I know that something real is happening. God help anyone who tries to get in the house if they ignore him.
My dogs don't bark except in case of warning, but there are differences with in that barking range as well as differences for the reasons they bark.

One of my three dogs uses her "warning bark" to get a preferred seat on the sofa next to us. If one of the other dogs is sitting or napping there, she executes the alarm bark while looking towards the door in the next room. As soon as the sofa is vacated and the other dog runs off, barking, to the door, she jumps up and claims the seat.

Maine Coon cats have an extraordinary range of vocalizations.

Live with one for a while. You may find yourself beginning to think "this isn't random, it's a working vocabulary" after listening to the cat carefully.

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Let's not conflate "meaning" in the sense of denotation, with "meaning" in the sense of "emotional information."

Interesting about dogs evolving barking behavior in response to living with humans. Various studies have shown that dogs have an exquisite degree of emotional sensitivity to human social situations. Much of human communication is conveyed not in the words themselves, but in the tone of voice.

Think of all the nuances that can be communicated by the phrase "Yes, Dear," depending on how it's spoken: romantic love, familial love, mutual agreement, grudging compliance, sarcasm, putting-down, and more.

It would not be surprising if dogs were operating on that basis: making and using subtle distinctions in the rhythm, tone, harmonics, timing, and duration of various components of what we think of as "barking."

And, like chimps taught sign language, once dogs have picked it up from humans, they would tend to use it in human-related social situations with each other.

As for dogs barking at the postal carrier or the refuse collectors, consider those situations from the dog's point of view: "Person comes to house, hands something to my human, my human has an emotional reaction, sometimes positive sometimes negative, therefore this person is a potential hazard..." and "My human carefully puts leftovers in a secure container outside, and then these guys come every week to steal it and feed it to the big animal they rode in on...."

As for cats: a close friend of mine trained himself to speak Cat effectively and with repeatable results. He also told me that my efforts at meowing were coming across as random gibberish. I'll have to keep in mind that item about the rising trill and the two-tone reply. They remind me of humans intonation for "Who's there?" and "It's me."

One more about dogs. Somewhere I read that their olfactory sensitivity is 30,000 x that of humans. Imagine living in that world: a symphony of smell!

As for measuring the effects of communication, the best way to do that is to tape electrodes to the dog's head and run an EEG looking for patterns of reactions.

I'm not scientist enough to analyze the research, so could someone explain why this study shows the claimed results? I just don't see a clear output. First, the dogs' reactions seem the same for each type of bark - an increased heart rate. Second, dogs, and other animals, can take cues from humans to adjust their behaviors (e.g., "counting"). The pups were with their owners, and previous studies showed that humans can recognize the difference in the barks. Thanks.

gort: All your points are valid ones. As noted, I think you could plausibly interpret this as saying that the dogs can detect (meaning have a physiological reaction) to a change in bark pattern and that's about it. There will always be some residual issues (e.g., whether the dogs got a cue from their owners) but I don't know the details of the experimental setup here to know how plausible that is.

g510 says, "Interesting about dogs evolving barking behavior in response to living with humans". Did dogs actually evolve the barking behavior in response to living with humans or did humans breed it in?

Pauls

There's a good chance that it was a side effect of selecting for more human friendly social behaviour rather than something we actively selected for, at least early on. Later we found some uses for it, and made some intentional selection for barking. The belling of hounds on the hunt comes to mind.

This unintended consequence was seen when such selection was intentionlly done with foxes.

While I realize it's not the best source, it's all I've got time for right now:

http://en.wikipedia.org/wiki/Tame_Silver_Fox

I think dogs do understand barks... after all, that is how they communicate with other dogs, right?