(khoahoc.tv) – Why are wolves forever wild animals, while dogs can be domesticated?
>>> Little-known facts about wolves
Dogs and wolves share a very similar gene pool, which makes it challenging for biologists to understand why wolves remain wild, while dogs can willingly become “man’s best friend.”
Currently, a doctoral study conducted by evolutionary biologist Kathryn Lord at the University of Massachusetts Amherst indicates that the different behaviors between dogs and wolves are linked to their earliest sensory experiences and the critical period of socialization. Details of this study are published in the journal Ethology.
To this day, scientists know very little about sensory development in wolf pups and often extrapolate from what is known about dogs, Lord explained. This is reasonable, except that scientists have observed significant differences in early development between wolf pups and dog puppies, primarily in the timing of their mobility, she added.
To clarify this, she studied the responses of 7 wolf pups and 43 dog puppies to both familiar and novel smells, sounds, and visual stimuli, testing them weekly and noting that they developed their senses simultaneously. However, her research also revealed new information about how the two subspecies of Canis lupus experience their environment during a 4-week developmental window known as the critical socialization period, and how new experiences can significantly alter our understanding of the development of both wolves and dogs.
When the “socialization window” opens, both dog puppies and wolf pups begin to walk and explore fearlessly, retaining familiarity throughout their lives with the things they encounter. Domestic dogs can familiarize themselves with humans, horses, and even cats during this stage and remain comfortable with them forever. However, as they grow, fear increases, and after the window closes, new sights, sounds, and smells can elicit a fearful response.
Through observation, Lord confirmed that both dogs and wolves develop their sense of smell by 2 weeks of age, hearing by 4 weeks, and vision on average at around 6 weeks. However, these two subspecies enter the critical socialization period at different ages. Dogs begin this period around 4 weeks, while wolves start from 2 weeks. Thus, the way each subspecies experiences the world during these critical months is distinctly different, seemingly leading to different developmental pathways, she said.
Lord first noted that wolf pups are not yet able to open their eyes or hear when they begin to walk and explore their surroundings at two weeks old. “No one knew this about wolves; when they start exploring, they have not opened their eyes, cannot hear, and at this stage, they primarily explore their environment through smell, which is very fascinating,” she remarked.
She added: “When wolf pups first hear, they are initially afraid of sounds, and when they first see, they are also frightened by new visual stimuli. As each sense becomes involved in the perceptual process, wolf pups experience a new round of sensory shocks that dog puppies do not.”
In contrast, dog puppies only begin to explore and walk after all three senses—hearing, smell, and sight—are functioning. Overall, “The differences between dog puppies and wolf pups in their early weeks are quite surprising, showing how genetically similar they are. Two-week-old dog puppies are essentially unable to stand and walk. Yet at this age, wolf pups can actively explore, walk robustly with good coordination, and begin to climb small steps and mounds.”
Significant differences related to the developmental processes in the experiences of dog puppies and wolf pups have created clear distinctions in their social relationships, especially with humans. This new information will aid in managing both wild and captive wolf populations, Lord stated.
