Study finds which dogs are more likely to reply to wolf howls

Domestication ‘fundamentally changed’ the vocal repertoire of dogs and their perception of howling

A study that evaluated the reactions of dogs to wolf howls has found conclusive evidence that some breeds were more likely to reply with their own howls than others.

Wolves typically use howls for long-distance communication with others, to mark territory boundaries and to define the position of other wolves, which, in most cases, also reply with howling, explained scientists, including those from Eötvös Loránd University in Hungary.

The tendency of dogs – that descended from wolves – to respond to howls from their wild cousins was assessed on the basis of the former’s breed, age and sex by scientists, who published their findings recently in the journal Communications Biology.

However, some dog breeds are known to howl in response to sounds like bells, sirens or music, while many others never howl even once during their life even though they are capable of doing so.

In the new study, scientists investigated whether specific breeds were more prone to howling and if this had a link with their genetic closeness to wolves.

They tested about 70 purebred family dogs by playing back recordings of wolf howls and observing the dogs’ reactions in a laboratory.

Unsurprisingly, the results suggested that breeds genetically closer to wolves were more prone to reply with their own howls while modern breeds reacted by barking instead.

“It seems that although howling is present in most breeds’ repertoire, it lost its functionality due to the changed social environment, thus, modern breeds do not use it in adequate situations,” study co-author Fanni Lehoczki said.

Scientists also found that the dog breeds that howl more also tend to show more stress-related behaviours in this situation.

They suspected that more ancient breeds, which are genetically closer to wolves, may be capable of processing information encoded in wolf howls better than modern breeds.

“Thus, ancient breeds of our study might become stressed by intruding on a pack’s territory and use howling for the sake of avoidance, just as wolves do,” said Tamás Faragó, another study author.

The study also noted that the genetic effect on howling appears to occur mainly among older dogs of over five years of age, suggesting there may be an experience- or age-related personality effect.

“It is possible that in line with our hypothesis, that howling appearing with a higher level of stress is a fear reaction - older dogs are more fearful, which was already suggested by previous studies, but these speculations require further investigation,” Dr Farago said.

Scientists also found that neutered male dogs lacking testosterone howled more in response to the wolf playbacks, indicating howling behaviour could be linked to male sex hormones.

“As neutered males are suggested to be more fearful, this result can be in line with our findings about responsiveness and more stressed behaviour. Thus, the dog howl may mean ‘I am scared, don’t come closer’,” Dr Lehoczki said.

Based on the results, domestication and selective breeding by humans “fundamentally changed” the vocal repertoire of dogs along with their perception and production of howling as well.

“Our results suggest that domestication impacts vocal behaviour significantly: disintegrating howling, a central, species-specific communication form of canids and gradually eradicating it from dogs’ repertoire,” scientists wrote in the study.