Ecology for dogs

Population and habitat of dogs

The global dog population is estimated at 900 million and rising. Although it is said that the "dog is man's best friend" regarding 17–24% of dogs in developed countries, in the developing world they are feral, village or community dogs, with pet dogs uncommon. These live their lives as scavengers and have never been owned by humans, with one study showing their most common response when approached by strangers was to run away (52%) or respond with aggression (11%). We know little about these dogs, nor about the dogs that live in developed countries that are feral, stray or are in shelters, as the great majority of modern research on dog cognition has focused on pet dogs living in human homes.

Competitors

Being the most abundant carnivore, feral and free-ranging dogs have the greatest potential to compete with wolves. A review of the studies in the competitive effects of dogs on sympatric carnivores did not mention any research on competition between dogs and wolves. Competition would favor the wolf that is known to kill dogs, however wolves tend to live in pairs or in small packs in areas where they are highly persecuted, giving them a disadvantage facing large dog groups.

Wolves kill dogs wherever the two canids occur. One survey claims that in Wisconsin in 1999 more compensation had been paid for dog losses than livestock, however in Wisconsin wolves will often kill hunting dogs, perhaps because they are in the wolf's territory. Some wolf pairs have been reported to prey on dogs by having one wolf lure the dog out into heavy brush where the second animal waits in ambush. In some instances, wolves have displayed an uncharacteristic fearlessness of humans and buildings when attacking dogs, to the extent that they have to be beaten off or killed. Although the numbers of dogs killed each year are relatively low, it induces a fear of wolves entering villages and farmyards to take dogs. In many cultures, there are strong social and emotional bonds between humans and their dogs that can be seen as family members or working team members. The loss of a dog can lead to strong emotional responses with demands for more liberal wolf hunting regulations.

Coyotes and big cats have also been known to attack dogs. Leopards in particular are known to have a predilection for dogs, and have been recorded to kill and consume them regardless of the dog's size or ferocity. Tigers in Manchuria, Indochina, Indonesia, and Malaysia are reputed to kill dogs with the same vigor as leopards. Striped hyenas are major predators of village dogs in Turkmenistan, India, and the Caucasus.

The spiked collar common on working and pet dogs is no mere ornament: it originated as a protection of the vulnerable neck of a dog from wolves, but also protects dogs from attacks by other dogs.

Diet

Despite their descent from wolves and classification as Carnivora, dogs are variously described in scholarly and other writings as carnivores or omnivores. Unlike obligate carnivores, dogs can adapt to a wide-ranging diet, and are not dependent on meat-specific protein nor a very high level of protein in order to fulfill their basic dietary requirements. Dogs will healthily digest a variety of foods, including vegetables and grains, and can consume a large proportion of these in their diet, however all-meat diets are not recommended for dogs due to their lack of calcium and iron. Comparing dogs and wolves, dogs have adaptations in genes involved in starch digestion that contribute to an increased ability to thrive on a starch-rich diet.