Comprehension of human pointing gestures in young human-reared wolves and dogs

1. Comprehension of human pointing gestures in young human-reared wolves and dogs Katherine Mahoney Minako Berthet

2. Background • Three mechanisms to facilitate animals success in locating hidden food based on human given cues: • Extensive experience with humans • Formal training to use human given communication cues • Evolution of domestication

3. Background • Evolution of domestication • Seen in puppies with limited human contact • Domestic cats, foxes selected for tameness • Evolution involves both divergent and convergent processes • Living in close contact, relying on human provision might be affected by similar selection pressures • Decrease fear of humans ect.

4. Background • Why test wolves vs. dogs? • Comparative studies show what features are likely because of domestications

5. Background • Ensure there are no priori reasons why one species cannot perform a task • Species compared must have the same environmental experiences both development and testing • Need to give “inferior” species the ability to improve

6. Background • Wolves and dogs are the most intensely investigated pair of a domesticated animal and its wild pair. • Studies have been small and limited • Found that wolves didn’t rely on any human gestures • questionable because of the different experiences

7. Background • Present study: • Larger sample size • Socialized to humans in the same way • Tested in the same manner

8. Goal of study • Test two behavioral aspects: • Dogs’ sensitivity to human gestural cues when locating hidden food • Tendency to look at humans in problem situations • Hand-raising/extensive experience with humans or formal training in object-choice tests

9. Study 1:comparing wolf and dog puppies in a two-way choice task with human distal pointing

10. Study 1: Subjects • Hand-reared wolves • 9 grey wolf pups taken from mother 4-7 days after birth. • Hand-reared dogs • 8 dog puppies from dog shelter litters taken from mother 4-10 days after birth • Pet dogs • 9 dog puppies from dog breeders were taken from mother 6-9 weeks after birth.

11. Study 1: Pretraining • Experimenter kneels in front of 2 bowls. • Subject and owner are facing the experimenter; owner is restraining subject. • Experimenter shows food to subject and slowly places it in one bowl, subject is then released. • Subjects that do not eat food are excluded from the test.

12. Study 1: Methods • Experimenter places food in one bowl then places bowls on floor. • Experimenter kneels by bowl, makes eye contact and pointed at baited bowl. • Clapping/name calling prior to pointing if no eye contact is made. • 5 seconds to choose correct bowl  praise and food.

13. Study 1: Results • Hand-reared dogs and pet dogs performed the same (above chance). • Hand-reared wolves did not perform above chance and did not maintain eye contact.

14. Study 2:use of different human pointing gestures in young wolves

15. Study 2: Methods • Subjects: 7 individually socialized wolf pups 7-11 months old (5 from the first study) • Same procedure as study 1 except now standing upright • 4m x 4m enclosure • 20 trial for each cueing type in a predetermined, semi random order

16. Study 2: Methods • Momentary distal pointing - Definite point for 1 second, then subject released, distance 50cm 2) Dynamic distal pointing -Held arm in position subject released, distance 50cm 3) Momentary proximal pointing -Definite point for 1 second, closer to bowl distance 10 cm 4) Touching -Touched rim of bowl, 1 second 5) Standing behind -Stepped behind bowl and looked at subject till it made its choice

17. Study 2: Results • Slightly elevated performance on hand-given gestures • Result of association from being hand fed? • Signs of learning • Possible effect of developmental maturation

18. Study 2: Results

19. Study 3:use of different human pointing gestures in young wolves

20. Study 3: Method • 4 wolves from Study 1 (but not used in Study 2) were tested in 22 sessions over 6.5 months. • Same five cues as Study 2 (but in a pre-determined order). • Momentary distal pointing (22 sessions = 220 trials) • Standing behind (4 sessions = 40 trials) • Dynamic distal pointing (6 sessions = 60 trials) • Touching object (4 sessions = 40 trials) • Momentary proximal pointing (6 sessions = 60 trials) • Control trial: no signals.

21. Study 3: Results

22. Study 3: Results • Most successful with gestures in which the experimenter’s hand or body was close to the baited container. • May be learned through feeding. • Little evidence of learning (small sample size?)

23. Study 4: comparing the wolves after extensive training and naïve dogs of same age in momentary distal pointing trials

24. Study 4: methods • Results of 10 wolves from the previous studies • Comparison 10 pet dogs • Dogs tested in a room at dog school • Wolves same 4m x 4m at the wolf-farm

25. Study 4: Results • No significant difference beteen trained wolves and naïve dogs in the number of their correct choices or their latency of eye-contact with the pointer • 5 wolves (50%) and 5 dogs (50%) chose correctly above chance • Number of correct choices of wolves increased since tests at 4 months and the latency of eye-contact decreased • Dogs did not show this impovement

26. Study 4: Results

27. Discussion: Summary • Removal of biases (phobias, differences in day to day interactions) is necessary. • Dog pups do not require special, intensive socialization to utilize a more difficult version of a pointing gesture. • Hand-reared wolves can only rely on some gestures spontaneously. • Wolves require months of training to reach same level of success that is spontaneously achieved by dogs.

28. Discussion • Associative: hand-rearing allows for the formation of association between human hand and food. • Communicative: distal pointing is not likely to be associative (chimps fail distal pointing at 20 cm!). • Dogs will follow gesture even if experimenter stands behind empty location.

29. Discussion: Evolution/Selection • Dogs have increased tendency to spontaneously make eye contact  selection of dogs that were perceptive to human cues. • High variability in wolves ability (despite close relation) indicates little selection of ability that is strongly selected in dogs. • Variation may be the basis for selecting ‘prospective’ companions from ancient wolf/dog populations during early domestication.