Unnatural Predators in a New Urban Ecosystem – Wire Science

Stray dogs have invaded a hallway leading to an academic building inside IIT Madras. Photo: Prakriti (IIT Madras wildlife club)


  • In the six decades since a large part of IIT Madras was carved out of the Guindy Forest, the number of people living on campus has increased significantly.
  • The resulting “urbanization” has degraded the habitats of monkeys, bonnet macaques, blackbucks, and monitor lizards, and has led to the spread of invasive species of plants and animals.
  • The increased human presence has accompanied an increase in the number of local dogs on campus, and they have become a threat to campus wildlife.
  • They are not predators per se because their numbers are disproportionately higher than ‘prey’.
  • Instead, dogs are fatal, the population supporting human activities and their free roaming in the streets and forests is justified by a misunderstanding of the environment.

Eighteenth-century Richard Brinsley Sheridan said, “Surely nothing is unnatural and not physically impossible”—and certainly nature is malleable. But it is important to pay attention to the basic principles of ecology when we modify, create and reconfigure the environment in which we live. Urban landscapes cannot be simply painted over landscapes. Complex species assemblages – from exotic, invasive and natural – are adapted to heavily modified urban habitats.

Free domestic dogs may have adapted to food waste in modern cities, and appeared specifically Predators of the remaining wildlife in the Jindi Forest in Chennai. However they are not desirable predators required to maintain a chital population (axis axis) under control. They aren’t even natural predators, but that’s not the argument.

They are a nuisance and disruptive to the urban ecosystem, and therefore undesirable. The laws of the land need to be modified to get around this reality. The fact that dogs have taken a common path1 to domestication also does not justify their presence as scavengers on the streets of our cities.

Habitat degradation

In the six decades since much of the IIT Madras was carved out of the Guindy Forest (protected forest), the number of people living on campus has increased by an order of magnitude. But the infrastructure that supports their lives and work has come at the expense of the campus’ unique biodiversity heritage. The built-up area of ​​IIT Madras, which is located in the ecologically sensitive area of ​​Guindy National Park (GNP), today is about 0.5 square kilometres.

This ‘urbanization’ has degraded the habitat of monkeys, bonnet macaques (Macaca Radiata), Black Bucks (Antilope cervicapra) and monitor lizards )Varanos Bengalensis) – to name only large animals registered on campus – this has led to the spread of invasive species of plants and animals. “If you look at the picture of the area from the 1960s, there was only Palmyra (Purasus FlavieverPalms, forests and grasslands,” said Ranjit Daniels, a curator at Care Earth, a nongovernmental organization. The trees are mostly planted and many of them are not native. Also, invasive Prosopis took over this area.”

Prosopis joliflora It is a shrub plant that has been recognized as an invasive species on multiple continents.

The increased human presence has been accompanied by an increase in the number of free domestic dogs (Familiar canis) on campus, and as expected, they have become a threat to campus wildlife. In 2020 alone, loose dogs killed 94 animals, including “75 deer and three black bucks.”

Wild animals and pet dogs

IIT Madras made an attempt to contain the pet dog population through the Animal Birth Control (ABC) program, but it was unsuccessful. Indeed, in the past two decades, evidence has accumulated to prove that the “official” ABC program of the Indian government has not worked anywhere in the country.

The logic of the Neutral Release Policy (CNR) has failed not only because of poor implementation but because of its very design, which goes against the principles of population dynamics.

A 2020 modeling study demonstrated that even in a best-case scenario, the CNR approach is unlikely to lead to the required level of population control for free-range dogs. As such, there is a need to overturn this unscientific dog management policy – which has also led to multiple lawsuits being filed against it in the Supreme Court.

Sometime in late 2020, IIT Madras removed free-range dogs to enclosures. But an NGO called People For Cattle In India has filed a public interest lawsuit (PIL) complaining about the “plight of dogs” against the institute in the Madras High Court. However, the court provided relief to the IIT, which requested that all dogs be removed from the campus. The court also ordered the relevant government authorities to “ensure that this danger is eliminated.”

The Prakriti Wildlife Club, formed by members of the community of engineers residing on the IIT Madras campus, also advocates for the canine threat on campus. Susie Farruges, Prakriti member and professor in the Department of Chemical Engineering, said they tried to implement ABC’s methods, which “did not work due to the constant influx of dogs from outside into campus.”

“Stray dog ​​lovers brought dogs from other places and released them on campus.”

According to her, Prakriti has also attempted to dispose of food waste on campus, which dogs feed on, and to “protect dogs” from entry points.

Varrujes was elated by the Supreme Court order and its effects on wildlife on campus. “We have a great experience with results to show. And for the record, we have had nine out of 11 blackbacks that survived this season after stray dogs were removed.” “It’s been a year or two in all these years.”

The need for natural predators

Domesticated dogs are known to be a threat to at least 80 species, including 31 in the Indian subcontinent that are classified as “threatened” on the International Union for Conservation of Nature’s Red List. Despite this awareness, these dogs are not recognized as Invasive species in India.

Even locally, in the small and isolated Guindy Forest, the survival of the Blackbucks population—which has the highest level of protection afforded by the Wildlife (Protection) Act 1972—is threatened by domestic dogs. There is therefore a strong environmental reason for the scientific community to propose declaring domestic dogs “invasive” and for all policy recommendations relating to Guindy’s forests that should be framed in accordance with this evidence.

In the Guindy Forest—now split into two parts by the IIT Madras campus and Guindy National Park—native free-range dogs thrive because there is plenty of food waste to feed on. But they are also present in large numbers due to poor population control policy.

“The ABC program does not work at all, and to say that spaying reduces their aggressiveness is nonsense. Even rabies control is not effective,” Daniels said. “In the absence of natural predators, dogs have emerged as predators.”

At the same time, treating dogs as “predators” in a scenario where the numbers of predators and prey are disproportionate does not make ecological sense. This means that dogs are not completely predators because the term means opposite a system in which groups of predators and prey co-evolve together and mutually regulate each other’s numbers.

For example, if there are many worms in an area, then many birds come to eat them. Thus the number of birds will increase over time, but this will lead to overfeeding of the worms. Eventually, the number of worms will decrease, and the number of birds will decrease as well. But as soon as there are fewer birds, the number of worms will start to increase again. and so on.

Instead, the dogs simply attack the killers in the Guindy Forest, with its inhabitants artificially supported by human activities and their free roaming of streets and forests justified by a misunderstanding of the environment.

The chital population still needs to be monitored, says Daniels, and the jackal (Canis aureus) are the animals that do this in the Guindy Forest. The jackal feeds on small animals, but among them are nails.

“It can be very difficult to have a large number of jackals in the isolated forest surrounded by a city,” Daniels said. “But if the habitat is restored by returning the former pasture area, removing the invasive Prosopis and non-native trees and removing dogs that are direct competition and also spread disease to jackals, then jackals can establish themselves.”

According to him, the IIT Madras campus can house 10 jackals and Guindy National Park can house 10 more jackals. And this, apparently, will be a self-sufficient population.

Narendra Patel She worked for the Wildlife Conservation Society (India) and Wildlife Studies Center for ten years, and with the Snow Leopard Conservancy (India Trust) in Ladakh for two years.

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