A study published last month in The Journal for Nature Conservation reported the presence of plastic and other human-made materials in elephant dung in the forests of Uttarakhand. The study authors investigated dung samples collected from four sites – three near the Haridwar Forest Division (Laldhang, Gaindikhata, and Shyampur), and one near Lansdowne Forest Division (Kotdwar).

Glass, metal pieces, rubber bands, clay pottery and tile pieces were the other materials that had found their way into pachyderm guts. This is the first systematic documentation that provides incontrovertible proof that elephants ingest non-biodegradable, toxic anthropogenic waste, and that it is moving through their digestive systems.

“It was horrifying to see how much plastic and other nonbiodegradable anthropogenic items were there in the elephant dung,” said Gitanjali Katlam, the main author of the study. She collected this data during her PhD at the Jawaharlal Nehru University.

“It was not surprising, considering that there have been reports of elephants feeding from garbage dumps near forested areas,” added Soumya Prasad, who was Katlam’s PhD guide at JNU, and is now a researcher with the Nature Science Initiative. “I feel that this data is just the tip of the iceberg. There is not enough research on how much plastic is being ingested by terrestrial animals. Over the last 20 years, there have been many anecdotal reports of plastic in the fecal samples of many species – it is just that the information is not compiled to provide a wider view of the problem.”

Katlam’s work shows that about one-third of all elephant dung samples collected showed the presence of anthropogenic waste. Roughly 85% of this was plastic (ranging in size from one millimetre to 35 centimetres), with each samples containing on average as many as 35-60 pieces of plastic. The study also found that macroplastics (larger than five millimetres) were more common than microplastics (one to five millimetres).

Plastic waste found in elephant dung (the pen is used for scaling). Plastics consumed by the elephants are carried deep into the forests, thereby increasing the chances of other animals consuming plastics. Photo by Gitanjali Katlam.

What was even more worrisome, according to Katlam, was that dung samples collected within protected areas (From 100 metres from the forest edge to 3 km within) contained nearly twice as many plastic particles (50–120 pieces per 100 gram of dung) as those collected from the forest edge (25 pieces-45 pieces per 100 gram of dung).

“It is an uncomfortable truth to face – that elephants ingest plastic along with food waste (discarded food often wrapped in plastic) and carry it deep into the forest,” she said. “Once the plastic exits the elephant’s system, it can continue to be a danger to other animals in the forest as it gets passed up the food chain.”

Anthropogenic waste

When Katlam was investigating how animals frequented garbage dumps as feeding sites in 2015, she recorded 19 bird and 13 mammal species. Though she did not observe elephants here, she spotted domestic cows, dogs and cats, sambar deer, langurs, Rhesus macaques and yellow-throated martens.

Despite spotting the sambar nibbling, tearing, and often gulping plastic waste, she is yet to observe plastic in their droppings. Given that they have ruminant stomachs – meaning that they have four compartments, like those of cows, Katlam is uncertain about how plastic is processed in their bodies.

“I worry that all that plastic may be getting impacted (getting stuck to the lining) in their stomachs and intestines,” Katlam said. “I know that when this happens in cows, it’s extremely dangerous to the animal; they often die of starvation.”

Apart from Katlam’s work and a study on elephants feeding at open garbage dumps in the Shivalik elephant reserve, there are few publications from India that report on wildlife feeding at garbage dumps. Another such report is on red foxes in the trans-Himalayan landscapes of Spiti Valley in Himachal Pradesh, which found that 84% of sampled red fox scats contained some form of human trash.

“We expected to find human-origin items in red fox diets during winter, since food resources are scarce in the snow-covered landscape,” said Abhishek Ghoshal, who worked on this project for his Master’s thesis from the Forest Research Institute University and Nature Conservation Foundation. “But we definitely did not expect so much.”

Currently working as a conservation scientist with Bombay Natural History Society, Ghoshal further adds that among the most surprising finds were “bottle caps, pieces of polythene, cloth, rubber bands, remains of cotton strings, and even wire. The red foxes, while foraging in and around garbage dumps, must have inadvertently eaten these items”.

In the trans-Himalayan region of Spiti valley in Himachal Pradesh, 84% of sampled red fox scats contained some form of anthropogenic waste, according to a report. Photo credit: Artemy Voikhansky/ Wikimedia Commons

Over the last few years, there have been alarming photos and reports of wildlife, including snow leopards, tigers, leopards and deer, feeding at garbage dumps or carrying plastic waste. The deaths of several rescued deer in Guindy National Park in Chennai were suspected to have been because of plastic ingestion.

Case studies

“Recently, one of my students reported the presence of diapers in elephant dung in Kabini,” said TNC Vidya, a professor at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bengaluru. This discovery occurred soon after news reports in January this year wrote about the presence of sanitary pads, masks, milk sachets, and biscuit packets in the dung of wild elephants on the Maruthamalai Temple Hill Road in Coimbatore.

Vidya, who has studied elephant genetics and socioecology for over 15 years in Kerala, Tamil Nadu, and Karnataka, further added, “But such instances are really rare – we see plastic in perhaps one sample in several thousand samples of elephant dung.”

She proposes several reasons for this. “One, we usually only take very small samples of dung from the surface of dung piles and do not really investigate the deeper contents of the dung,” Vidya said. “Two, a lot of our work is in fairly remote sites where human presence is usually minimal and third, we have not really made an effort to check if there are microplastics in these dung samples.”

However, Vidya agreed that plastic is present even in the densest and remotest of her field sites, largely carried there by waterways. “The forest department conducts cleanliness drives every year, but there’s only so much they can do. So, it’s not very surprising that some plastic does get into elephant guts,” she added.

Ratna Ghosal, who worked on elephants from 2004 to 2010 at Mudhumalai Wildlife Sanctuary, says that she had never come across plastic in elephant dung during her field sampling days. “Firstly, I did not check for microplastics and secondly, I am not sure if the elephants in Mudhumalai ever fed on garbage piles during the time I worked there,” Ghosal said. “Although there were garbage piles near the forest edge, these were next to a very busy road which had a high volume of traffic passing through it.”

“I have only observed elephants using that area to cross the road to reach another forest patch,” Ghosal said. “I have never seen them stop to forage for food.”

Poor waste management

Ghoshal, who currently studies communication in fish and the reproductive physiology of crocodiles as a professor at Ahmedabad University, agrees that plastics are a major issue in terrestrial systems and freshwater bodies.

“In Vadodara, which is one of the field sites for our crocodile studies, we often see crocodiles in areas riddled with plastic refuse,” Ghoshal said. “Although we do not study this, I am sure the heavy pollution in the Vishwamitri river and vast expanses of floating plastics are taking a toll on the health of the crocodiles there.”

Despite there being plenty of photographic evidence that plastics are adversely affecting freshwater systems and terrestrial animals, including humans (microplastics have now been found in human blood, placenta, and the faeces of newborn babies), research is severely lagging. Most investigations on the threats posed by plastic pollution to wildlife and the environment continue to be focused on marine environments. However, scientists are realising the importance of plastic pollution in terrestrial and freshwater ecosystems.

A camera trap image from 2015 of a yellow-throated marten foraging for food at a garbage dump. Experts have raised concerns over photos and reports of wild animals carrying plastic or feeding at garbage sites. Photo credit: Gitanjali Katlam

Besides this, plenty of research has highlighted how improper waste disposal not only exacerbates human-wildlife conflict, but also affects the health of populations, changes animal behaviour and demographics. Garbage piles also attract large packs of feral dogs which have been seen attacking or chasing wildlife, particularly snow leopards and bears, thus affecting their ability to hunt prey.

The tidal wave of plastic waste that has been engulfing the world since the Covid-19 pandemic has also brought our meagre abilities in handling waste into sharper focus, and efforts are underway to determine how discarded personal protective equipment is harming wildlife.

As Katlam et al write in their paper, it is imperative to now develop “a comprehensive solid waste management strategy through mapping of garbage dumps, conducting risk assessment to the wildlife, and mass awareness campaigns to mitigate the threat of plastic pollution”.

This article first appeared on Mongabay.