Ajay Immanuel Gonji
Introduction
In an earlier article, I had talked about a unique behaviour in street dogs where they are known to respond to high-pitched anthropogenic sounds such as sirens by means of howling. While I researched this particular behaviour, I was drawn to several other aspects of dog behaviour which I was absolutely fascinated by. In this article, I will be talking about certain interesting aspects of dog behaviour and ecology, most of which I have drawn from a book by Raymond Coppinger and Lorna Coppinger called What Is a Dog? (2016). When I talk about street dogs, I am referring to the free-ranging dogs that we often see in the streets of cities, towns and villages in India.
What are Street Dogs?
According to the Merriam-Webster dictionary, a “domestic” animal refers to any of various animals domesticated so as to live and breed in a tame condition. However, an interesting definition provided by the Coppingers refers to domestic animals as species that can eat in the presence of people. By this definition, all animals and birds, including monkeys, squirrels, pigeons, etc. that we encounter on a daily basis, especially in a city like Delhi, are all domestic animals. Of course, the street dog also falls within this category, for it is one species which eats food almost always in the presence of human beings.
Although all canids such as wolves, coyotes, jackals, dingoes, and dogs are interfertile (can mate with each other and produce offspring) and are known to interbreed and hybridize, they are adapted to different niches. While wolves, coyotes, jackals and dingoes are well adapted to the wild, street dogs are almost never found in the wild but have developed their own unique niche in close proximity to human beings. Further, unlike the so-called “pure-breed” dogs which are a product of ‘artificial selection’ by human beings who repeatedly select for specific traits over several generations, the street dog is a product of ‘natural selection’ and is its own natural species. Although they are not controlled by humans, they are commensals (living in close association) and depend on human-derived food waste as their primary food source (Vanak & Gompper, 2009).
While wild canids have the perfect shape, size and instincts for life in the wild, and pure-bred dogs are artificially created by humans to have characteristics which make them ideal “pets”, street dogs have carved out a unique niche for themselves around humans by being scavengers of human-generated food waste. Street dogs are generalists in their habitat and are known to occupy a variety of habitats all over the planet and are active wherever and whenever humans are active (Banerjee & Bhadra, 2019). It is said that their unique niche was created when human beings shifted from hunting and gathering to growing food crops. However, interestingly, not all street dogs around the world look the same but have distinct characteristics depending on geographical location, climate and food resources. For instance, dogs that live high up in the mountains are a lot bigger in size and have thicker coats as compared to the dogs living in the plains.
Survival of the Fittest
As stated in the preceding section, street dogs are a unique species whose existence depends on living around humans and subsisting almost entirely on the food waste generated by humans. Dogs are also particularly adept at calmly waiting for food to come to them rather than spending time and energy in searching for food. This inherent trait of the street dog decreases its transportation and acquisition cost in terms of energy spent on finding food. This is in stark contrast to wild canids which must spend a lot of time and energy in searching for food that is highly sporadic. The energy that the street dog saves in acquiring food is then channelized to other aspects of its life. For instance, dogs are able to not only reproduce much faster but also have larger litter sizes as compared to wild canids. While a female dog can come into heat every six months provided she does not have a litter, female wild canids will come into heat only once a year. Also, while the breeding cycle in wild canids is in response to climatic conditions and availability of resources, street dogs do not have any such constraints and can reproduce any time of the year.
Related to breeding is also the fact that street dogs are highly promiscuous and will often mate with multiple partners. This is because the objective of dogs, much like other species, is not to survive physically but to survive genetically. For instance, mating with several females increases the chances of a male to pass on his genes to the next generation. Similarly, a female in heat will often mate with several males and give birth to a litter in which each pup has a different father, thereby increasing the chances of passing on her genes to successive generations. Interestingly, because a male cannot be sure of whether a female he mated with is pregnant with his progeny, male dogs will almost never invest their energy in parental care. This again is in stark contrast to wild canids where a lot of energy is spent on parental care by both males and females. In this case, because males and females usually form long-term bonds, a male has an advantage in investing energy in parental care because all the pups in the litter belong to him and will probably be responsible for carrying his genes to successive generations.
If street dogs are such prolific breeders, how is it that the planet is not exploding with dogs? Here is where the carrying capacity of the dog’s niche comes into focus. The size of the niche or the amount of available resources in a particular habitat will decide how many individual dogs can be accommodated in that niche. In other words, the niche to which the dog has adapted is not infinite and therefore only a certain number of individuals, whether adults or juveniles, will be able to occupy that niche. For instance, if a particular habitat is at full carrying capacity and is composed of a large proportion of adult dogs, it is likely that that system will not be able to support any new individuals, even if they are offspring of the same adult dogs. Conversely, offspring are likely to survive and thrive in a habitat where there are only a few adult dogs and where full carrying capacity has not yet been reached. In other words, a good survival rate of adults will result in a large mortality rate among pups, and a large mortality rate of adults will result in a better survival rate of pups.
Conclusion
Although dogs are known as humans’ best friend, studies on them have largely focused on pure-bred pet dogs, while investigations on the behaviour and ecology of street dogs in their natural environment are very few (Majumder et al., 2014). Yet, what is quite probable is that dogs are humans’ best friend not because they like us but because the survival of their entire species depends on being in close proximity to human beings and subsisting on human-generated food waste. At this point, I am reminded of the many times I have observed local village dogs in mountainous regions accompany tourists on hikes and treks. I am almost convinced that those dogs were not offering or looking for companionship but were simply seeing tourists as a source of food. As stated by Coppinger & Coppinger (2016), it could well be the case that the special relationship between humans and dogs is something which the dog is initiating for its own survival.
References
- Banerjee, A., & Bhadra, A. (2019). Time-activity budget of urban-adapted free-ranging dogs.
- Coppinger, R., & Coppinger, L. (2016). What Is a Dog? Chicago and London: The University of Chicago Press.
- Majumder, S. Sen, Bhadra, A., Ghosh, A., Mitra, S., Bhattacharjee, D., Chatterjee, J., … Bhadra, A. (2014). To be or not to be social: Foraging associations of free-ranging dogs in an urban ecosystem. Acta Ethologica, 17(1), 1–8. https://doi.org/10.1007/s10211-013-0158-0
- Vanak, A. T., & Gompper, M. E. (2009). Dogs Canis familiaris as carnivores: their role and function in intraguild competition. Mammal Review, 39, 265–283.
