From guarding your house and livestock to being your best friend playing with you on the couch, dogs have come a long way in the past 33,000 years. But, there is another disturbing aspect to this saga of furry friends; Canis lupus familiaris (dog, for short) is also an ‘invasive’ species in many ecosystems! Like the Japanese kudzu vine or the infamous Lantana, dogs are a non-native introduced species that are wreaking havoc on the ecological balance of many sensitive ecosystems. Now, a study by researchers from the Ashoka Trust for Research in Ecology and the Environment explores the effect of free-ranging dogs, or strays, on their surroundings in India.
How bad are dogs really to our ecosystems, you ask? Previous studies have shown that domesticated dogs have imperilled 188 threatened species of animals and caused 11 mass extinctions, globally! “Domestic dogs have been considered as invasive mammalian predators. After cats and rodents, they are the third most damaging invasive predators”, says Ms. Chandrima Home, one of the researchers of the study, in an interview to Research Matters.
In countries like India, where the population of stray dogs are surging by the day without checks and bounds by a governing body, these dogs turn feral—a state in which they are neither truly wild not truly domesticated. “Unlike cats and rats which perhaps target smaller sized animals, feral dogs can target a larger range of prey size as predators as they can hunt in packs. Their impacts are as detrimental as cats and rats, though cats and rats have reported higher extinction for biodiversity”, adds Ms. Home referring to previous studies and their own findings.
The present study is the first ever assessment of the impact dogs have on the biodiversity in India. The researchers used a two-pronged approach to collect data for the study—an online survey and print media. They conducted an online survey where they asked the respondents to give details about any attacks on wildlife carried out by dogs. In the print media, they looked for keywords like ‘stray dog’, ‘dog attack’, ‘dogs attack wildlife’ and related terms in newspaper reports published between the 1st of January 2015 to the 30th of June 2016.
Among the 249 respondents who took the online survey, a whopping 73% said they had seen stray dogs attack wildlife. The researchers recorded 403 incidents of attacks by dogs on wildlife from the online survey, and 57 incidents from print media! They found that 80 species were under attack by dogs, including four ‘critically endangered’ species, twelve ‘endangered’ species, eight ‘vulnerable’ species and seven ‘near threatened’ species. From the survey results it would seem that no prey is too big for the dogs! They were recorded hunting sambar deer, blackbucks and on one occasion, they were chasing a leopard.
The study shows that the threat from dogs on wildlife is real and could come in the way of conservational efforts. So, what can we do to curb this conflict? Managing dog population is the key, say the researchers. The survey respondents also seem to agree on this as 87% of the respondents felt the need to control dog population near wilderness areas. The researchers opine that in order to protect local wildlife and ensure a good quality of life for dogs, carefully planned population control programs should be implemented near protected forest areas.
“When it comes to dog population management, nobody actually wants to look at one of the most important problem in India—dog ownership policies. People like to feed dogs (an easy way to show compassion) but do not want to be responsible pet owners. Also, sterilization is considered the only way to curb population. No one talks about reducing garbage or food for dogs. The general idea prevalent is that dogs are born to feed on garbage. I think the basic attitude in India needs a change”, explains Ms. Home.
Domesticated dogs are adding a new dimension to the threats many species of wildlife are already facing due to habitat loss, deforestation, encroachment, etc. Man’s best friend is turning out to be biodiversity’s biggest enemy, as this research shows.