This is the third in a 6-part series. Read the first and second parts
On August 11, a 2-judge bench of Justice J B Pardiwala and Justice R Mahadevan directed that stray dogs be removed from the streets of Delhi and the National Capital Region as early as possible.
The bench had taken suo motu cognisance of a news report in the Times of India’s Delhi edition on July 28. It noted that the news item contained “very disturbing and alarming” figures and facts.
The Chief Justice of India B R Gavai later shifted the case from a two-judge Supreme Court bench to a three-judge one. The new bench, headed by Justice Vikram Nath and comprising Justices Sandeep Mehta and N V Anjaria, reserved its order on an interim plea seeking a stay on the earlier directive on August 14.
On August 22, 2025, this bench stayed the earlier order directing the removal of free-ranging dogs from the Delhi-National Capital Region to shelters, while ruling that feeding them in public spaces is illegal.
Down To Earth (DTE) wanted to probe the issue further. In nature, dogs and vultures often compete for carcasses. We wanted to understand the reason behind why dogs have become a menace for humans and non-human animals alike. Could the decline of the vulture in the 1990s have contributed to the dog’s rise?
DTE spoke to a number of experts on the matter. Here, we talk to veteran expert on vultures, Vibhu Prakash.
According to Prakash, there is anecdotal evidence of free-ranging dog populations increasing with the decline in vulture numbers. However, it is very difficult to quantify this given that there is no systematic historical record of India’s canine population.
Down To Earth (DTE): What happens in an ecological niche/guild when a big predator/scavenger goes?
Vibhu Prakash (VP): When a big scavenger is removed from the ecological guild, a lot of dead biomass remains for a long-time giving opportunity for the population of undesirable secondary scavengers to increase multifold. There are very few specialist scavengers which have evolved for scavenging like vultures. Specialist scavengers are very efficient in removing the dead biomass as they are well equipped to do it. Such scavengers usually can eat 40-50 per cent of their body weight when food is in abundance and they could go hungry for weeks and are also highly mobile and can reach long distances in short time. Dead meat is virtually a culture medium of disease causing bacteria and fungus, and when an animal dies, these organisms quickly colonise the dead body and breed in millions and then form spores. Once they have formed spores they reach water and soil and cause disease when they come in contact with a healthy host, be it a human or domestic animal and cause disease. The big scavengers, when present in the ecosystem, quickly remove the dead biomass and prevent the multiplication of disease causing organisms. The number of secondary scavengers grows in absence of large scavengers but as they are not efficient scavengers, they are not able to remove the dead biomass which allows the disease causing bacteria and fungi to multiply. The secondary scavengers themselves are reservoirs of many diseases and an increase in their population is a serious health hazard.
DTE: Has the decline of the vulture due to the diclofenac debacle led to the rise of free-ranging dogs? Has the availability of food led to the dog becoming a top predator?
VP: There is anecdotal evidence that the number of free-ranging dogs have increased as a result of a crash in vulture populations. When the vultures were in good numbers, they would descend on the carcass of an animal as soon as it was thrown out in the open and literally cover up the body and dogs would have no chance to get at the carcass. Now, in the absence of vultures, the dogs get to eat a lot of meat throughout the year. Dogs, like any vermin, have a bigger litter size when they get good nutritious food. This certainly has led to an increase in their numbers. It is very difficult to quantify the increase in dog population because of the crash in vulture population as the dog population was already very high in the country and there is no systematic historical record of their population.
Dogs by nature are predators and are largely carnivorous. They are social animals, remain in packs (groups) and also hunt in packs. Dogs are also cannibals and usually litter at places where other dogs cannot reach. But with abundant food available, they litter in the rib cages of cattle at carcass dumps. Such pups, which grow up in carcass dumps, hardly come across humans or livestock. So when they see humans or cattle, they attack. They also become more ferocious because of the kind of food they get and due to the distance from humans. Consequently, such dogs have become top predators in the areas where big cats are not present.
DTE: Has the range of free-ranging dogs increased in India in tandem with the decline of the vulture?
VP: I do not think this could have happened. Range increases when there is a food shortage and neighbouring territories are vacant. In this case, there is plenty of food everywhere and they do not need to move a lot.
DTE: What consequences does this have for ecosystems?
VP: There are going to be disastrous consequences:
The increase in secondary scavengers like free-ranging dogs, feral pigs and rats will have long term consequences on the ecosystem.
Dogs are becoming a serious problem for ground nesting birds as they pick up eggs and chicks and sometimes adult birds. They hunt down deer and antelope outside as well as inside protected areas.
They have become a serious problem to small mammals like hares and foxes and small cats. Similarly, feral pigs that eat carcasses also cause problems in the ecosystem. They are a serious pest in agriculture as they could plough the entire field full of ripe crops overnight.
The population of rats has also increased dramatically near carcass dumps. Rats are known pests for agriculture and birds.
DTE: How do you see this in the context of the latest SC judgement regarding stray dogs?
VP: Free-ranging dogs have become a very serious problem and I do not think anybody has a simple solution. There are over a million dogs in Delhi alone and over 60,000 dog bites a year. This really calls for drastic action and short-term patch work solutions will not work. When humans were not such an important factor in the ecosystem, nature was in charge and was balancing various elements. Humans have modified the ecosystem completely and therefore, we will have to deal with this problem. Nature alone cannot address it.
If you ask population biologists, they would suggest measures to keep populations of various species in check. The species whose populations decline, will require measures like added protection, habitat protection and restoration, conservation breeding and rewilding, etc. The species whose populations are exploding will require neutering, relocation and rehabilitation through adoption, and even culling in extreme cases. Based on population models, population biologists can recommend what proportion of the population should be neutered, relocated/rehabilitated or even culled.
I think the strategies recommended by population biologists must be implemented scientifically, under the guidance of senior wildlife veterinarians and in total without any bias to region, religion or personalities. That is the only sustainable, long-term solution to the problem.