Why does the dog wag its tail? It's only a communication tool, doesn't help in manoeuvres
We all love watching dogs when they wag their tails, people say they wag their tails to show excitement or happiness. But scientists and dog lovers still wonder what is the actual purpose of the dog's tail. Entire research by an international team went into this, and they concluded that the tail cannot wag the dog.
Various studies in the past have shown that numerous animals from lizards to squirrels use their tails to pull off impressive manoeuvres such as righting themselves mid-air when falling from trees. Cats also use their tails to balance themselves when flipping over and landing on their feet, they also use their tail as a counterweight to perform extreme hunting moves in the wild, including rapid, tight turns to keep up with their prey.
As dogs are more inclined to stay on the ground, scientists have been unclear whether dogs' tails help them with agile movements or not, said a report in The Guardian. Some were of the opinion that a dog's tail primarily served as a waggable communication device, and/or to ward off unwanted visitors such as flies.
To know more about this, Dr Ardian Jusufu, who studies animal locomotion at the Max Planck Institute for Intelligent Systems in Stuttgart, and his colleagues built a mathematical model that allowed them to check what happens when dogs twist and turn their torsos, and move their legs and tails when they bound into the air.
The study concludes that "Tail wags the dog is unsupported by biomechanical modelling of Canidae tails use during terrestrial motion." In simple words, the tail movements made by dogs made almost no difference to a dog's trajectory when it leapt into the air.
The findings suggest that tails are not as critical for agile movements in dogs as they are for other animals. Moving the tail mid-jump, the researchers found, changed the dog’s trajectory by a mere fraction of a degree.
Across the dog family, "It appears the inertial impacts that tail movement has on complex manoeuvres such as jumping, have little to no effect," the authors write. "The utilising of the tail during jumping … achieves very low amounts of the centre of mass movement across all species with the largest being under a single degree."
"We believe that this implies that dogs utilise their tails for other means, such as communication and pest control, but not for agility in manoeuvres", they further added.
According to previous research, dogs use their tails to communicate everything from dominance and friendliness to fear and appeasement. A tail held high signifies confidence or a dog’s willingness to play, while a stiff tail can express a threat or anxiety. When the tail is down low or tucked between the legs, the animal might be afraid, but loose wagging from side to side communicates friendliness.