Tag Archives: Messerli Research Institute

Gambling wolves take more risks than dogs

Would you rather get 100 euros for certain, or have a fifty-fifty chance of receiving either 200 euros or nothing? Most choose the first, as humans tend to be “risk-averse”, preferring a guaranteed pay-off over the possibility of a greater reward. It is thought that the human preference for “playing it safe” has evolved through natural selection: when you live precariously, like our remote ancestors, losing all your food reserves might be catastrophic, while adding to them might not make much difference to your chances of survival.

Wolf pups

Etu and Ela, two wolf pups at the Wolf Centre Photo credit: Rooobert Bayer

Here, in one of the first studies on risk preferences in animals other than primates, scientists show that wolves are consistently more prone to take risks when gambling for food than dogs. When faced with the choice between an insipid food pellet and a fifty-fifty chance of either tasty meat or an inedible stone, wolves nearly always choose the risky option, whereas dogs are more cautious.

“We compared the propensity to take risks in a foraging context between wolves and dogs that had been raised under the same conditions,” says Sarah Marshall-Pescini, a postdoctoral fellow at the Messerli Research Institute at the Veterinary University of Vienna and the Wolf Science Centre, Ernstbrunn, Austria, the study’s first author. “We found that wolves prefer the risky option significantly more often than dogs. This difference, which seems to be innate, is consistent with the hypothesis that risk preference evolves as a function of ecology.”

The study was done at the Wolf Science Centre, Ernstbrunn, Austria, a research institute where scientists study cognitive and behavioral differences and similarities between wolves and dogs. Here, wolves and dogs live in packs, under near-natural conditions within large enclosures.

Marshall-Pescini let each of 7 wolves and 7 dogs choose 80 times between two upside-down bowls, placed side-by-side on a movable table-top. The animals had been trained to indicate the bowl of their choice with their paw or muzzle, after which they would receive the item that was hidden beneath it.

The researchers had taught the wolves and dogs that beneath the first bowl, the “safe” option, was invariably an insipid food pellet, while beneath the second bowl, the “risky” option, was either an inedible item, a stone, in a random 50% of trials, and high-quality food, such as meat, sausage, or chicken, in the other 50%. As a control, the side for the “safe” and “risky” option changed between trials, but the animals were always shown which side corresponded to which option; whether they would get a stone or high-quality food if they chose the “risky” option was the only unknown. Rigorously designed control trials confirmed that the animals understood this rule, including the element of chance.

Wolves are much more prone to take risks than dogs, show the results. Wolves chose the risky option in 80% of trials, whereas dogs only did so in 58% of trials.

The researchers believe that dogs evolved a more cautious temperament after they underwent an evolutionary shift from their ancestral hunter lifestyle to their present scavenger lifestyle, which happened between 18,000 to 32,000 years ago when humans first domesticated dogs from wolves. Previous research has suggested that species that rely on patchily distributed, uncertain food sources are generally more risk-prone. For example, chimpanzees, which feed on fruit trees and hunt for monkeys, are more risk-prone than bonobos, which rely more on terrestrial vegetation, a temporally and spatially reliable food source.

“Wild wolves hunt large ungulates — a risky strategy, not only because hunts often fail, but also because these prey animals can be dangerous — whereas free-ranging dogs, which make up 80% of the world’s dog population, feed mostly by scavenging on human refuse, a ubiquitous, unlimited resource. So dogs no longer need to take risks when searching for food, and this may have selected for a preference to play if safe,” concludes Marshall-Pescini.

Source:  EurekAlert! media statement

Happy faces/sad faces

This is the experimental set-up used to test whether dogs can discriminate emotional expressions of human faces.  Photo by Anjuli Barber, Messerli Research Institute

This is the experimental set-up used to test whether dogs can discriminate emotional expressions of human faces. Photo by Anjuli Barber, Messerli Research Institute

Dogs can tell the difference between happy and angry human faces, according to a research published recently in the journal Cell Biology.

The discovery represents the first solid evidence that an animal other than humans can discriminate between emotional expressions in another species, the researchers say.

Previous attempts had been made to test whether dogs could discriminate between human emotional expressions, but none of them had been completely convincing. In the new study, the researchers trained dogs to discriminate between images of the same person making either a happy or an angry face. In every case, the dogs were shown only the upper or the lower half of the face. After training on 15 picture pairs, the dogs’ discriminatory abilities were tested in four types of trials, including (1) the same half of the faces as in the training but of novel faces, (2) the other half of the faces used in training, (3) the other half of novel faces, and (4) the left half of the faces used in training.

The dogs were able to select the angry or happy face more often than would be expected by random chance in every case, the study found. The findings show that not only could the dogs learn to identify facial expressions, but they were also able to transfer what they learned in training to new cues.

“Our study demonstrates that dogs can distinguish angry and happy expressions in humans, they can tell that these two expressions have different meanings, and they can do this not only for people they know well, but even for faces they have never seen before,” says Ludwig Huber, senior author and head of the group at the University of Veterinary Medicine Vienna’s Messerli Research Institute.

This research adds to the body of knowledge about the human-animal bond.  The researchers believe it is likely that the dogs associate a smile with a positive meaning and an angry expression with a negative one.

Source:  EurekAlert! media release

 

Attentiveness in dogs

Photo by Angela Gaigg

Photo by Angela Gaigg

Researchers at the Messerli Research Institute at the Vetmeduni in Vienna have researched dogs’ attentiveness and how it changes over their lives – and the patterns shown are similar to humans!  The results have been published in the journal Frontiers in Psychology.

Dogs are individual personalities, possess awareness, and are particularly known for their trainability. To learn successfully, they must display a sufficient quantity of attention and concentration.

The study’s lead author, Lisa Wallis, and her colleagues investigated 145 Border Collies aged 6 months to 14 years in the Clever Dog Lab at the Vetmeduni Vienna and determined, for the first time, how attentiveness changes in the entire course of a dog’s life using a cross-sectional study design.

To determine how rapidly dogs of various age groups pay attention to objects or humans, the scientists performed two tests. In the first situation the dogs were confronted with a child’s toy suspended suddenly from the ceiling. The scientists measured how rapidly each dog reacted to this occurrence and how quickly the dogs became accustomed to it. Initially all dogs reacted with similar speed to the stimulus, but older dogs lost interest in the toy more rapidly than younger ones did.

In the second test situation, a person known to the dog entered the room and pretended to paint the wall. All dogs reacted by watching the person and the paint roller in the person’s hands for a longer duration than the toy hanging from the ceiling.

The dogs generally tended to react by watching the person with the object for longer than an object on its own. The team found that older dogs – like older human beings – demonstrated a certain calmness. They were less affected by new items in the environment and thus showed less interest than younger dogs.

In a further test the scientists investigated so-called selective attention. The dogs participated in an alternating attention task, where they had to perform two tasks consecutively. First, they needed  to find a food reward thrown onto the floor by the experimenter, then after eating the food, the experimenter waited for the dog to establish eye contact with her.  These tasks were repeated for a further twenty trials. The establishment of eye contact was marked by a clicking sound produced by a  “clicker” and small pieces of hot dog were used as a reward. The time spans to find the food and look up into the face were measured. With respect to both time spans, middle-aged dogs (3 to 6 years) reacted most rapidly.

“Under these test conditions, sensorimotor abilities were highest among dogs of middle age. Younger dogs fared more poorly probably because of their general lack of experience. Motor abilities in dogs as in humans deteriorate with age. Humans between the age of 20 and 39 years experience a similar peak in sensorimotor abilities,” says Wallis.   

Dogs also go through a difficult phase during adolescence (1-2 years) which affects their ability to pay attention. This phase of hormonal change may be compared to puberty in Man. Therefore, young dogs occasionally reacted with some delay to the clicker test. However, Wallis found that adolescent dogs improved their performance more rapidly than other age groups after several repetitions of the clicker test. In other words, the learning curve was found to be steepest in puberty. “Thus, dogs in puberty have great potential for learning and therefore trainability” says Wallis.

Source: Vetmeduni media release

The ability for dogs and wolves to learn

Wolves can learn from observing humans and pack members where food is hidden and recognize when humans only pretend to hide food, reports a study published for the first time in the open-access journal Frontiers in Psychology.

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions.  Photo by Wolf Science Center

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions. Photo by Wolf Science Center

These findings imply that when our ancestors started to domesticate dogs, they could have built on a pre-existing ability of wolves to learn from others, not necessarily pack members.

A paper published recently in the journal Science suggested that humans domesticated dogs about 18 thousand years ago, possibly from a European population of grey wolves that is now extinct. But it remains unknown how much the ability of dogs to communicate with people derives from pre-existing social skills of their wolf ancestors, rather than from novel traits that arose during domestication.

In a recent study, Friederike Range and Zsófia Virányi from the Messerli Research Institute at the University of Veterinary Medicine Vienna investigated if wolves and dogs can observe a familiar “demonstrator” – a human or a specially trained dog – to learn where to look for food within a meadow. The subjects were 11 North American grey wolves and 14 mutts, all between 5 and 7 months old, born in captivity, bottle-fed, and hand-raised in packs at the Wolf Science Center of Game Park Ernstbrunn, Austria.

The wolves and dogs were two to four times more likely to find the snack after watching a human or dog demonstrator hide it, and this implies that they had learnt from the demonstration instead of only relying on their sense of smell. Moreover, they rarely looked for the food when the human demonstrator had only pretended to hide it, and this proves that they had watched very carefully.

The wolves were less likely to follow dog demonstrators to hidden food. This does not necessarily mean that they were not paying attention to dog demonstrators: on the contrary, the wolves may have been perceptive enough to notice that the demonstrator dogs did not find the food reward particularly tasty themselves, and so simply did not bother to look for it.

Source:  EurekAlert! press release