Growls Don’t Lie

“When growling, dogs don’t lie about their size,” states Péter Pongrácz, an ethologist at Eötvös Loránd University in Hungary. In a recently completed study in a controlled setting, dogs were shown projected images of two different-sized canines while a centrallyplaced speaker emitted a growl that corresponded with one of the two projected images. The watching canines were filmed to see which way they looked, and for how long. 20 out of the 24 test subjects matched the sound to the correct projection, meaning that dogs are able to judge another dog’s size by his growl alone and listen to growls to determine their fight or flight reaction. Pongrácz’s original study, undertaken with colleagues, proved that dogs use a specific growl when guarding a bone; this knowledge is now furthered by the understanding that other dogs, with only the information provided by a growl, can not only tell whether the growling canine is guarding food, but can also ascertain the size of the foodguarding canine.