Most dog owners know that dogs bark at intruders and associated outside noises. Actually, many dog owners know that their dogs bark in a variety of contexts and situations.
It can be said that barking is a “hypertrophied” trait in dogs, when we compare it to the amount of barking in the wild canids.
Dogs have been reported to bark when they are excited about going on walks, when dinner time is around the corner, when intruders approach the home and when they are left alone.
Barking at intruders and outside noises is a common behavior and it can be triggered by just about anything, from the noise of the wind, to sensing other dogs barking or a distant siren from a fire truck.
Interestingly, research has revealed some interesting findings which may explain why dogs may be so prone to barking inside of the home when they sense the presence of intruders and outdoor noises.
Is Barking the Result of Selective Breeding?
Throughout history dogs and humans have been social partners, with both species reaping several mutual benefits.
Humans provided dogs with food, shelter and water. Dogs, on the other hand, helped humans in several ways such as through their warnings of danger (barking), localization of prey, and as effective hunting partners.
It comes natural to therefore think that dogs were selectively bred for their barking.
After all, a dog with no bark would have failed in alerting humans of many dangers such as invasions of enemy tribes or presence of wild animals!
What Research Reveals
Interestingly, a study has closely analyzed the barking behaviors in canines and has found that many species (from jackals to coyotes and wolves) tend to vocalize when intruders approach their dens.
This makes sense from an adaptive standpoint since this is where young, vulnerable pups are found and where escape behavior is impossible.
Based on this, it can be hypothesized that dogs have a tendency to bark more when housed in domestic environments with minimal escape routes.
Confined in a crate, kennel, house or fenced yard, dogs are therefore prevented from evading approaching intruders and are left with only the option to "confront them."
Interesting Findings on Village Dogs
This hypothesis is further reinforced by the fact that, research by Boitani et al. (1995) found that, free-living “village dogs” who are never confined, exhibit much lower levels of barking towards human intruders or strange dogs.
The exception to this was when the core of their territories were "invaded."
Research by Ortolani et al. backs this up as village dogs in Ethiopia were found to significantly increase their vocalizations when confined in homes, compared to when they were roaming freely and approached on a street.
A Matter of Confinement
A dog's tendency to bark is believed to be genetically transmitted. Indeed, dogs who are born deaf were found to start their barking behavior at the same time as normal hearing dogs, and they would even bark in the same way.
Selective breeding though may not be the ultimate cause of the increased barking seen in dogs compared to their wild counterparts.
Research therefore seems to suggest that the frequency of our domesticated dog's bark is the result of being introduced to our domestic environment and its associated artificial restraint.
Barking as "Mobbing Behavior"
Barking can therefore be compared to the "mobbing behaviors" observed in birds.
Basically, when a predator (or in this case an intruder) is detected, birds move rapidly and on occasion reunite in a joint physical attack with the intent of sending the intruder away.
The mobbing behavior is typically started by one individual who firstly detects the intruder and signal the approach through animated vocalizations. Conspecifics may soon join in with the goal of sending the intruder away.
Such behavior has also been reported in canines.
McNay (2002) conducted an assessment of several wolf and human interactions taking place in Alaska and Canada from 1900 to 2001.
Wolves were reported to bark and run towards and away from humans when they approached their dens or rendezvous sites.
A Socially Facilitated Behavior
Barking often is described as being a socially facilitated behavior.
In other words, when one dog starts barking, all dogs living nearby may start to bark, suggesting the phenomenon of social contagion.
With this in mind, according to the research conducted by Kathryn Lorda, it can be concluded that the relatively close living quarters of captive dogs, helps facilitate group vocal response to a mobbing signal.
This explains the cacophony that often follows the initial barking of a single animal.
Why Do Dogs Approach to Bark?
In the wild, we expect most canines to flee given the opportunity.
An exception may be when a canine parent stands her ground at the den to protect the vulnerable pups.
In dogs though, it appears that they may approach rather than flee, even when they have the option to escape, why is that?
Most likely, this is because dogs compared to the wild counterparts, have a decreased fear of novelty and this causes them to sometimes put themselves into conflicting situations.
On top of this, a dog's barking may be reinforced by owner attention. This includes attention of the negative type.
For example, if a dog barks at outdoor noises, most owners will do something about it. They may go check at the window, or they may tell the dog to shush in an upset tone.
These are all forms of attention, and for a dog who craves it, they can reinforce the barking, making it more likely to occur in the future.
- Barking and Mobbing Kathryn Lorda,∗, Mark Feinsteinb, Raymond Coppinger, Behavior Processes s 81 (2009) 358–368