Garbage Dumps Are Changing the Food Habits of Wild Animals

Garbage dumping sites are already known to have both physical and toxicological effects on animal life.

New Delhi: Modern day garbage dumps, which are full of harmful products and chemicals, are emerging as a serious threat to animal and plant life. Now, a new study has found that these dumps are shifting their food habits as well.

The main culprit is plastic waste, known to cause health complications and disrupt reproductive patterns in animals that accidentally ingest it. It also causes environmental pollution through chemicals that are leached out of it, and into the soil.

The study examined the relationship between animal type and behaviour vis-à-vis the risk of plastic ingestion.

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The researchers used direct observation as well as infrared camera-traps to monitor animal visits and food intake behaviour at two sites in Nainital district, Uttarakhand. The instruments scanned the sites once every 10 minutes for two to three hours a day, for two months.

They recorded frequency with which animals and birds visited the selected garbage sites, and their feeding patterns. A total of 32 such creatures were identified feeding on the garbage.

Uttarakhand was picked for the study because it has a sizeable tourism industry, and tourists generate a lot of garbage in and around wildlife habitats. The two spots chosen in Nainital have been or are visited by over 200 bird species and 75 mammals around the year.

The dumping site was characterised by leftover food mixed with non-biodegradable waste such as plastics, glass bottles, metal cans, light bulbs, cartons, etc.

Based on the animals’ and birds’ behaviour, researchers divided them into different groups. Peckers, who used beaks to pull food out from plastic items, included 19 species of birds. The second group, handlers, included two species of animals with hand-like front body parts able to segregate food from other waste.  The last group identified was gulpers, which lacked hand-like organs as well as mouthparts, and thus could not separate food from plastic items.

In all, the researchers found that each animal or bird spent 2.8 minutes at a garbage site on average. The large-billed crow had the highest contact rate with plastic while the sambar had the lowest.

Among the three types of animals, the handlers and peckers came in contact with with plastic items twice as much as the gulpers.

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“An ecological shift is happening where a few animal species at some places are becoming more dependent on anthropological food waste,” Geetanjali Katlam, a member of the research team and a behavioural ecologist at the school of life sciences, Jawaharlal Nehru University, Delhi, told India Science Wire.

“If we don’t enforce proper waste management strategies, particularly in and around natural sites and forest areas, it would have disastrous implications on wildlife.”

Garbage dumping sites are already known to have both physical and toxicological effects on animal life. For example, when an animal eats a plastic item, the item injures its digestive tract and can cause ulcers in the stomach, reduced fitness, growth problems and – ultimately – a premature death.

The study concludes that waste from domestic activities and other activities should be segregated at the source itself to prevent them from harming animals when they’re exposed to the environment. It will also help mitigate the impact of non-biodegradable waste accumulation.

The study was published in the December 25, 2018, issue of the journal Current Science.

Rayies Altaf writes for India Science Wire and tweets at @rayies_sts.