- In Spiti Valley in northern India, red foxes can be seen rummaging through kitchen waste. Such dumpster diving could potentially bring wild animals in close proximity to humans and increase conflict, researchers say.
- Increasing reliance of wild animals on food waste could affect other ecological processes.
- In the state of West Bengal, for example, some troops of rhesus macaques spend most of their time “begging or chasing” tourists for food. These troops, unlike the forest-dwelling ones, contribute very little to the dispersal of seeds, researchers have found.
Spiti Valley, located in the remote Trans-Himalayas, is one of the least populated places in India and home to several rare and endangered wild animals. Here, to see wild herbivores like the Himalayan ibex (Capra sibirica) you may have to trek up to mountain pastures sometimes 5,000 metres (16,404 feet) high. If you want to see a snow leopard (Panthera uncia), you may have to track herds of the Himalayan blue sheep (Pseudois nayaur) and hope to run into a snow leopard doing the same thing. If it is a Himalayan wolf (Canis lupus filchneri) you want, well, good luck to you.
But for a red fox (Vulpes vulpes), just go back to a village and take a quiet walk after dinner. You are likely to see a fox rummaging through the kitchen middens – small heaps of food scraps usually discarded in the backyard.
Even in this landscape of vast open spaces, people and wildlife can’t help rubbing shoulders, according to researchers from the Wildlife Institute of India (WII). In a recent study published in the Journal of Arid Environments, the researchers analysed the diet of red foxes from five locations in three states across the trans-Himalayas and one location in the Dachigam National Park in Kashmir. In locations close to human habitation, such as Spiti Valley, Ladakh and Chiktan village in Kargil, between 30 to 55 percent of the food red foxes ate came from human sources.
Humans in the Himalayas are inadvertently providing a substantial amount of food to these animals, including discarded meat bones, fruits, dead livestock, cereals and inedible things like plastic, paper, or rubber, which the researchers euphemistically termed Human Derived Materials (HDM).
This is not a new phenomenon, nor is it restricted to red foxes.
Cosmopolitan eaters
Scientists have pointed out that humans have been subsidizing the diet of wild animals since we were hunter gatherers discarding remains of kills. Indeed, the domestic dog is believed to have evolved from an ancestor who was attracted to the prehistoric man’s rubbish dumps.
The options have only increased with time. Today, wild animals can access human subsidised food from kitchen middens in villages, garbage dumps, and landfills in big cities, discarded fish catch in coastal areas and even directly when people fed animals like monkeys.
Thomas Newsome, an ecologist and lecturer at the University of Sydney, Australia, who has been studying the consequences of food subsidies to wild carnivores like dingoes (Canis lupus dingo), said that most species that consume food waste are generalists who don’t depend on specific foods.
Red foxes are particularly cosmopolitan in their eating habits. This species which is found across the Northern Hemisphere, eats rodents, small birds, eggs, lizards, insects, fruits, berries, and scavenges on other animals’ kills.
Quick and easy meals
So, the transition from this versatile diet to dumpster diving in the Himalayas seems unsurprising. But what is the motivation? What were the animals thinking?
“I am getting food, without expending too much energy,” said Bilal Habib, a scientist at WII and one of the lead researchers of the red fox study.
Such a diet can be beneficial for animals like red foxes in the short term. Studies show that provisioning increases the animals’ body weight, increases fertility and improves chances of mating and having offspring.
One of the reasons for this is that provisioned food is typically, “predictable, calorie-rich and [an] easily digestible source of food,” said Asmita Sengupta, an ecologist at the Ashoka Trust for Research in Ecology and Environment (ATREE) in Bangalore, India, who studies the effect of food provisioning in rhesus macaques (Macaca mulatta) in the Buxa Tiger Reserve in the eastern state of West Bengal.
Newsome added that a shortage in the natural food supply could also drive wild animals towards human subsidies.
But the costs of such behavior far outweigh the benefits, all three researchers said.
The dangers of quick meals
Even in the remote Trans-Himalayas, the waste humans generate nowadays includes plastic and medicines that are very likely to be harmful for red foxes, Habib pointed out.
Such dumpster diving also brings to fore a bigger and more powerful carnivore competitor — the domestic dog. In 2015, researchers from the conservation groups Nature Conservation Foundation in India and the Snow Leopard Trust, U.S., reported that red foxes and dogs were often attracted to the same villages and garbage dumps in Spiti. The presence of dogs didn’t seem to convince the smaller, usually solitary fox to stay away. These stray or feral dogs moving in packs can attack foxes and spread diseases like canine distemper in the wild animals.
Even if no stray dogs were present, Habib said that there were other problems with wild animals accessing food waste.
“I expect two red foxes to occur naturally around the village, but this garbage sustains five or six. A wildlife lover may think this is a good thing, [but] in the long run this may bring the species in conflict,” he said.
Newsome agreed, adding that provisioning increases chances of conflicts with people. “Food waste also acts as a magnet for wildlife activity, so it can potentially draw animals in close proximity to humans,” said Newsome leading to attacks on livestock or even people in case of large predators.
“Even communities who are tolerant of wild animals right now can develop a negative attitude in such a case,” added Habib.
A disproportionate increase in wild animals like red foxes could also affect other animals in nature, through a phenomenon called hyper-predation, where a boost to carnivore numbers because of the garbage would lead to a simultaneous increase in attacks on natural prey species like pika (Ochotana roylei) in the case of red foxes. But the prey species wouldn’t be able to keep up with the predator numbers and eventually would die out. With no natural prey, the carnivores would be even more reliant on waste.
Rhesus macaques eating food scraps affects forest dynamics
Reliance on provisioning also disrupts larger ecological processes like regeneration of forests, Sengupta of ATREE and her team reported in a 2016 study published in the International Journal of Primatology. In the Buxa Tiger Reserve in North Bengal, the researcher studied two troops of rhesus macaques. Macaques are a particularly familiar sight in human-dominated areas, especially in India where people often directly and deliberately feed these animals.
In Buxa, however, Sengupta found one troop that lived entirely inside forests and ate mostly wild fruits (around 79 percent of their diet), and had no contact with people or their food. Sengupta found that this wild troop dispersed seeds of a whopping 84 percent of the fruits they ate. At least 50 percent of these seeds germinated, helping plants spread and grow.
The other troop of macaques lived on the fringes of the forest, next to a state and national highway and a tea shop. For seven months of the year, this troop spent most of their time at the tea shop in turns, begging or chasing tourists for food and returned to forage in the forest when the reserve was closed for tourists.
Fruits formed only 46 percent of their diet, and the macaques dispersed 24 percent of the seeds on the highway where they wouldn’t grow, as opposed to the wild troop that dispersed all of the seeds in the forest. During the peak tourist months, the provisioned troop ate no fruits and dispersed no seeds.
“I would expect any region in northern and northeastern India, where forests are relatively undisturbed and where there are fruiting tree species, to be places where rhesus macaques can act as important seed dispersers,” said Sengupta.
While humans feeding the macaques was disruptive to this important process, Sengupta said that as long as human beings encroached on forests, animals would continue depending on anthropogenic food. She is hopeful, though, that the non-provisioned troop in Buxa would for now at least continue staying in forests, “if there are preferred food species in the forests.”
To deal with the problem, Newsome said that “people must ask why the wildlife are consuming food waste or other forms of food provided by humans. If they are just eating it because it is accessible, then this food source should be removed or made inaccessible to wildlife. But if the wildlife are turning to eat food provided by humans because there are no alternatives, then steps should be put in place to restore prey availability and viable habitat.”
Citations:
Reshamwala, H. S., Shrotriya, S., Bora, B., Lyngdoh, S., Dirzo, R., & Habib, B. (2018). Anthropogenic food subsidies change the pattern of red fox diet and occurrence across Trans-Himalayas, India. Journal of Arid Environments.
Newsome, T. M., & van Eeden, L. M. (2017). The effects of food waste on wildlife and humans. Sustainability, 9(7), 1269.
Ghoshal, A., Bhatnagar, Y. V., Mishra, C., & Suryawanshi, K. (2016). Response of the red fox to expansion of human habitation in the Trans-Himalayan mountains. European journal of wildlife research, 62(1), 131-136.
Sengupta, A., & Radhakrishna, S. (2016). Influence of fruit availability on fruit consumption in a generalist primate, the rhesus macaque Macaca mulatta. International Journal of Primatology, 37(6), 703-717.
Newsome, T. M., Dellinger, J. A., Pavey, C. R., Ripple, W. J., Shores, C. R., Wirsing, A. J., & Dickman, C. R. (2015). The ecological effects of providing resource subsidies to predators. Global Ecology and Biogeography, 24(1), 1-11.
Sengupta, A., McConkey, K. R., & Radhakrishna, S. (2015). Primates, provisioning and plants: Impacts of human cultural behaviours on primate ecological functions. PloS one, 10(11), e0140961.
This story was first published on May 3, 2018, by Mongabay-India.
