My mom is a Canis Lupus
Written by Ida Hambiralovic 2005
Among pets, the dog is more than common. This loving and playful animal is of great joy and comfort to millions of people. It is considered to be mans best friend, yet not so many years ago in evolutionary terms the predecessor of canis familaris, the wolf spread fear and terror among the prehistoric humans. Somewhere along the time line of evolution the wolf was tamed and the dog appeared.
For many people around the world the dog is a trusted family member, it is allowed to play with our children and sleep in our bedroom. Yet considering the relatively short period of time it took for the wolf to transform, can we be sure of if the shiny white canine and the incisors of the dog are actually presenting a smile, and not a sign of hunger and aggression.
What is a dog?
The long process of genetic divergence of the dog from its ancestor was accomplished by important behavioural changes that could have genetic basis because of a selection pressure for dogs that were able to adapt better to the human social setting.
But does this mean that we can blindly trust these newly created animals?
Recent studies have shown that dog’s performance at some communicative task is surprisingly good in comparison, to chimpanzees.
Dogs have the ability to use different forms of human directional gestures, to find hidden food indicated by a human, and they can also inform humans about locations of hidden food by gazing at it.
These are all signs to that the dog has fully adapted it self in a human environment, and in a way chosen the life within a human family.
But how much is it left of the wolf inside this new-created animal. One way to investigate the genetic effects on dog behaviour is to compare the dog’s behaviour with that of the nearest living relative, the wolf (canis lupus).
Two certain studies have been performed concerning this particular case. Trying to compare the behaviour of a dog and a wolf, and their associations to humans.
Experimental
procedures:
Subjects (for study1 and study2)
In 2001 and 2002, there were individually raised two groups of wolf puppies from day 4 with 24 hour human contact in family homes. At 3 months of age, the animals were transferred to a farm where they lived together in a large garden around a house. Apart from the owners of the farm, who had daily contact with the wolves, the caretakers visited them as well.
In general, this means that the wolves have experienced a very similar rearing environment, just as dogs living in families.
(Study 1)
Investigations of how four socialized wolves perform in two way object choice task. The object is a bowl, one containing food (raw meat), and one empty. The experimenter is standing between the two containers, 1.5 m apart. The performance was obtained for three different gestural cues:
-distal pointing (the index finger of the human is about 50 cm from the object)
-proximal pointing (5-10 cm away from the object)
-touching (the human touches the object physically)
The data of the first and last 20 trials were analyzed. At the end of the test series, 20 control trials were used without the use of any gestures.
The performance of each wolf was analyzed individually. Similar testing situation were performed with dogs instead of wolfs.
Procedures (study1)
The tests were carried out in a kennel at the farm where the animals lived. The test sessions started when the wolves were 4 months old and were staged once a week for the following 7 month period.
Two bowls of brown plastic were used to hide the bait, which were small pieces of raw meat. The animals had not eaten at least 1 hour prior to the training session.
Previous studies have shown that olfaction does not play a role in this context, but prior to starting the experiment trials, both bowls were rubbed inside with a piece of meat.
The experimenter showed a piece of food to the subject (wolf) and than placed it into one of the bowls with slow movements so that the animal could see the baiting. Than the subject was allowed to go to one of the bowls and was encouraged to eat the food. If the subject visited the empty bowl first, it failed to get the food.
This was repeated with distal pointing gesture, proximal and touching the bowl.
The wolves were tested continuously during the whole period with the distal pointing gesture. On the 17th week of training, the touching gesture was introduced and was followed by testing with the proximal pointing gesture on the 23rd week. Control trials were staged on the last 2 weeks of testing.
Procedures (Study2)
Both wolves and the dogs were tested at an outside area at the dog school.
Study 2 consisted of two behavioural tests, a bin-opening and a rope-pulling test, in which such gazing/looking behaviour was tested directly.
Bin test:
A normal litter box with lid was used as container of the meat in this test. The test animals were placed 1.5 m form the box with their owner 1m further back. In the first ten trials the experimenter would place a piece of meat inside the litter box whilst the subject could not see it. When the subject was turned around and watched the experimenter, the lid of the bin was opened and the piece of meet given to the animal. In the next round the subject was left to open the bin on their own to get the meat, the time it took for each subject was clocked. For the blocked test trial the lid would be fixed mechanically, and during two minutes the attempts of the subject to get the lid open was videotaped and analysed to note the looking behaviour of the test subjects.
Rope-pulling test:
The test animals were placed in front of a wire mesh cage.
In the warm up trials the experimenter would crouch into the cage and through the bars offer the test animals a piece of raw meat, which they were allowed to eat upon retrieval.
After this session the next step was initialised.
In this setting the meat inside the cage would be attached to a 40 cm long rope, were 15 cm would extend outside the cage. For the test animal to obtain the meat it would have to pull the rope.
During the test the owner or caretaker of the animal would stand 1 m behind the animal. In the blocked trial the rope would be fixed to the cage so that pulling the rope would not move the food an inch.
Again the owner would be place 1 m behind the test animal, so that for the animal to look at its owner it would have to turn away from the food.
Results (study1)
The statistical analysis showed that the performance was at chance with “distal pointing” gestures at the beginning of the test, but one wolf increased his performance significantly by the end of the experiment, and was correct in 80% of the trials.
Further in the cases of “touching” all individuals performed well over chance.
Two individuals preferred to choose the container indicated by “proximal pointing” gesture.
In sum, all the wolves performed over chance in at least one condition.
Overall, it seems that when they experience appropriate rearing conditions, wolfs can learn about human cuing.
These results may indicate that wolves in fact can learn about some human gestures, but their performance is generally worse than that of the dog in a similar testing situations, and there is a large individual variability among wolves.
This might be explained by the fact that wolves had many opportunities to learn that the human hand is often associated with the presence of food.
To be able to explain the “distal pointing” gesture, the wolves have to look on the human as well on the bowl containing food. They need to associate the signs given by the human (pointing), with the food.
Wolves simply avoid looking at humans, or they look only for a short period, so therefore they are not able to perceive the directionality of the gesture.
We can say today that we assume that one of the first steps in the domestication of the dog was the selection for “human-like” communicative behaviour.
As the study showed, there are individual differences among wolves in behaviour variability; this species might have been predisposed for successful selection to take place.
In other words, we created the dog out of the wolf that could “trust” the human.
Results (study2)
The results from the bin test and the rope pull showed that whilst there were no difference in the ability and motivation to solve the problems to get the food, during the blocked test the dogs would turn to their owner much faster and for longer time than the wolves would. Of the nine wolves that took part in the test only two turned towards their human caretaker, for the dogs this was however the other way around. This observation suggests that, when the dogs were faced with difficulties they would initiate contact (eye contact) earlier and for longer time that wolves. Also the dogs tend to have a not so strong attraction towards the food as that that of the wolves.
Of all the animals in wild-life kingdoms, why did we choose the wolf, the canis lupus, to be the animal which we bring into our homes, into our shelters? Make it a part of our human family. Why is the wolf incomparable to any other species? What makes it so unique?
Although this project showed us that there are major differences between the dog and the wolf and their behaviour towards humans, one of the wolves had developed a deeper contact or understanding with the humans. This might have been the reason to why the wolf thousands of years ago were chosen to be the companion of the human hunter. By choosing these wolves who were more ample to cooperate with the humans and crossbreeding them, the prehistoric people got themselves a friend whom which they could communicate and utilise for practical tasks. However the project showed only if the wolves who were raised by humans would behave like dogs and not whether dogs raised in the wild would still be able to learn from and cooperate with humans.
And so I will always wonder, if the wolf in my golden retriever is still alive or lost forever.
Sources: “A Simple Reason for Big Difference: Wolves Do Not Look Back at Humans, but Dogs Do” 2003
Adam Miklosi, Enyko Kubinyi, Jozef Topal, Marta Gasci, Zsofia Viranyi and Vilmos Csanyi.
Special thanks to Peter Kabai and his encouragement for pursuing this topic.