Welcome back to Science Sunday
It is pretty obvious and well known that dogs bond with their human families, but do they sense any kinship with their actual parents?
Domestic dogs share most of their genetic makeup with wolves, and the familial bonds in the wolf population are well documented. Contrary to popular belief, wolf packs are generally made up of families. The male and female bond for life and raise litters together with the male sharing in the workload. For example, the male Gray Wolf is typically extremely faithful to his mate and will bring her food her after she gives birth so that she can focus on the newborn litter. Father wolves are also very protective of their pups, guarding them from danger at all costs. And they are responsible for teaching the young cubs important survival skills, such as hunting.
As usual when humans get involved things get messed up. Pups are generally weaned at eight weeks of age and sent to their new homes. The father, if even present, has little of no contact with the pups. So is there any familial recognition at all?
Several interesting studies were carried out by Peter Hepper, from the School of Psychology at Queens University of Belfast, Northern Ireland. In one experiment, two bitches of the same age and breed were placed in enclosures at each end of a room, one of the bitches being the mother of a litter. A puppy would enter at one end of the room and the experimenter recorded which of the areas he went to first and how long he spent attending to the dog in that place. The results were unequivocal with 84% of pups choosing their mother. The experiment was repeated with litter mates as the target. Pups from their own litter were placed in one location and those of another litter at another, and again when a pup was brought in, they chose their own litter mates 67% of the time. The mechanism of identification was identified by Hepper as scent by replacing the actual target animals with their scent (towels on which either the bitch or the litter had laid). The results were almost identical with the previous experiments with 82% showing a preference for their mothers scent to some other bitch and 70% choosing the towel impregnated with their litter mate's scent over that of another litter.
Hepper repeated part of the experiment with dogs of two years age who were separated from their mothers at eight weeks. First the mothers were given the choice between fabric impregnated with the odour of their two year old offspring and another with the odour of some other dog of the same age and breed. The mothers clearly recognized their offspring's scent 78% of the time.
The experiment was then reversed to see if the offspring could recognize their mother's scent and again the results were unequivocal with the mother's scent chosen 76% of the time.
So, its clear that their is a lingering familial recognition between mothers and offspring, but not so much with the father. Male dogs generally greet their offspring in the same way that they would greet any other dog. Once the pups grow, he may indeed play with them, but that interest isn't much different from the interest in other non-related pups. Having a father-and-son relationship doesn't necessarily mean an absence of altercations or violence; paternal attacks on pups are unfortunately not unheard of.
So, sorry Twist nothing in the mail for you on Father's Day.