Domesticated dogs share many traits with their wild relatives, but distinct differences exist as well. Science hasn't completely caught up with the various differences, due largely to the fact that the DNA of domestic dogs (Canis familiaris) is nearly identical to that of gray wolves (Canis lupus).
Feeding is both similar and different in domesticated dogs and gray wolves. Wolves hunt in packs, taking down large prey to feed their family groups. A hierarchy is derived between the pack, with the alphas feeding first, followed by other adults and then the juveniles. While the diet of the domestic dog still relies heavily on animal proteins, the domestication process has changed their diet to more closely mimic that of humans. One theory suggests this is because, as dogs became domesticated, they largely survived from scavenging the leftovers of human hunts. As time progressed, the first domesticated dogs survived heavily off of "table scraps" from human meals, meaning they were getting more fruit, vegetables and grains in their diet than their wild counterparts.
Feral dogs are those that are, by definition, wild. They are more than a generation away from domesticated pets. Feral dogs are largely scavengers as opposed to hunters, although pack hunting does take precedence in some feral groups. They are more opportunistic feeders than hunters. This behavior more closely mimics their close relative, the coyote. Some feral packs feed largely on human garbage, while others take down livestock such as chickens. Feral dogs form packs, like many wild canines. In the United States, most feral dogs look similar to huskies and German shepherds, although the wide range of breeds and interbreeding result in a variety of appearances in feral dogs.
Reliance on Humans
Domesticated dogs have grown undoubtedly reliant on the cues, care and behaviors of their human counterparts. Many pet dogs, certain breeds in particular, wouldn't survive without the care of a human. Genetic mutations caused by selective breeding, such as short snouts and hairless coats, sadly reduce the dog's ability to provide for itself. These mutations combined with the overall care humans provide create a creature more dependent than independent. That being said, some domestic dogs are resourceful enough to survive and sometimes thrive when left by their humans to do so. Even some wild canines have greatly come to rely on the presence of humans to survive by eating trash and taking shelter in man-made buildings.
Wolf vs. Dog
During the late 1900s and early 2000s, several studies of the differences between wolf and dog behavior were conducted. One such study dealt with the difference between human-raised wolf pups and human-raised domestic dogs. Although both were raised in the same manner, as the wolves matured, they showed no reliance on humans and had no interest in pleasing their owners. The dogs, on the other hand, relied upon humans and took great interest in pleasing their owners. The domesticated dog relies heavily on human motions, such as pointing, on a daily occurrence. The domesticated dog can also read human emotions by studying the human face. The studies show the distinct differences in these two species despite their close relation and nearly identical DNA sequences.