Hungry as a bear: anthropogenic food impacts polar bear mortality

Environment | Tundras and Poles

By Sophie Coxon, Kingfisher writer

Published April 3rd, 2023

Incidents of human-wildlife conflict are growing as global climate change alters and degrades habitats, forcing wild animals into closer contact with people. One of these animals is the polar bear, with individuals increasingly being observed entering settlements, attracted by anthropogenic food sources.

Species conservation is facing an increasing issue with human-wildlife conflict, which has led to resistance and hostility towards wildlife that comes into contact with humans. This is often characterised by the predation of livestock by large carnivores and has been amplified both by the recovery of species populations and the shrinking of their habitats, forcing them closer to human settlements.

Human-wildlife conflicts are on the rise as vital habitats, such as the arctic ice sheets, disappear and force wildlife into closer contact with humans. | Hans-Jurgen Mager / Unsplash

Human-wildlife conflict incidents are commonly observed in towns and cities, where animals such as magpies, pigeons, rats and foxes are attracted to human rubbish. Anthropogenic food waste is an easy source of calories for wildlife, providing rich energy input for little energetic output, in contrast to foraging or hunting down live prey.

However, supplementary food provided by anthropogenic sources can have both positive and negative effects on wildlife, with the latter being recorded more frequently. Changes to survival and reproduction, body condition, health, spatial distribution and population dynamics have all been linked to anthropogenic food consumption by wildlife, raising concerns of conservation scientists with the increasing overlap between human and wildlife habitat ranges.

In the past, polar bears have rarely been observed near human settlements. Polar bears naturally hunt between floating ice sheets at sea, where they can predate blubber-rich seals that provide a long-lasting source of energy for the bears. This means that polar bears on land are usually in a fasted state, awaiting the seasonal return of the winter ice to bring back their hunting grounds.

With the decrease in Northern ice coverage and the shortening of its presence each year, polar bears are struggling to find suitable hunting grounds and enough prey to support their populations. This has led to bears spending more time on land, increasing the chance of human-bear conflict and the consumption of human food.

‘With the decrease in Northern ice coverage polar bears are struggling to find suitable hunting grounds.’

A subpopulation of polar bears found in Hudson Bay, Canada, has been forced onto land due to seasonal ice retreat and is commonly observed near the town of Churchill. For the past five years, they have been attracted to the settlement of human food waste in bins and rubbish dumps.

As a result, the bears have become conditioned to visit the sites annually and are increasingly habituated to humans. This poses a large threat to both the bears and the local community. Polar bears are large creatures and can cause substantial property damage, in addition to human injury and potential fatalities.

To deal with the problem, polar bears were physically removed from the area and relocated. Attempts have also been made to manage the dump on a strict habitual cycle where it is only in use at certain times.

The ‘problem’ polar bears were temporarily held at a wildlife facility until the Hudson Bay ice sheets refroze. However, this is not a sustainable way to manage the issue as wildlife must be able to coexist alongside humans, without the need for intervention or partial captivity.

Polar bears rely on adequate sea ice to allow them to successfully hunt seals. | Hans-Jurgen Mager / Unsplash

Rubbish dumps have also been documented to attract polar bears in Russia, such as in Ryrkaypiy in 2019, when 60 polar bears were reported gathering at the dump to scavenge for food. Importantly, all bears were assessed as having body condition of ‘below-average’, likely due to the delayed formation of sea ice that year and restricted ability to hunt prey.

The polar bears caused substantial effects on the local people’s lives, entering the village and damaging property, causing the cancellation of public events and preventing people from leaving their homes due to the safety risk. Although the bears left with the reformation of the ice and life continued as per usual, indicating that this phenomenon is linked to the impact of global warming.

Polar bears may also be drawn to settlements or camps by smaller-scale attractants, such as cooking aromas, domestic animals, and other human-related odours. In Ontario, Canada, annual geese hunting occurs in the polar bear territory along the western coast of James Bay, with hunters living in small camps. Polar bears can smell the stored geese and commonly raid them, and as a consequence are shot by the hunters protecting their harvest.

Another concern raised by this human-bear interaction is the nutritional value of the food obtained. Polar bears typically subsist on a high-lipid diet sourced from seal meat and blubber, as it provides them with a rich energy source to survive the cold winters and harsh weather of the far north.

‘In Ryrkaypiy in 2019, 60 polar bears were reported gathering at the dump to scavenge for food.’

In contrast, anthropogenic food is often much less nutrient-dense, and/or contains an unbalanced macronutrient ratio for optimum health in polar bears. For instance, the scavenging of goose carcasses from hunting camps provides a big hit of protein with little fat and due to the higher metabolic cost of protein ingestion, this can lead to polar bears losing indispensable weight leading to winter deaths.

Additionally, the food in our bins tends to be high in sugar or carbohydrates, macronutrient ratios that do not occur naturally in a polar bear’s diet which makes it difficult for them to process.

Research has found that anthropogenic food does not increase survival or reproductive rate in the bears and comes with the additional risk of ingesting non-food items such as packaging.

Furthermore, the congregation of bears around anthropogenic food sources means large groups of bears, which are usually solitary, are regularly coming together. This increases the chance of disease spreading, as well as bears being exposed to novel pathogens at rubbish dumps, which can threaten entire populations as resistance is not yet developed.

Polar bears spend increasingly long periods on land due to the annual decline in sea ice, causing concern over increased human-wildlife conflicts. | Mathieu Ramus / Unsplash

Currently, there are disputes in Svalbard, Norway, about the future of a polar bear mother, known locally as Micha (Frost), due to conflicts with local people. Micha is a successful mother who has raised multiple cubs and contributed greatly to the local polar bear subpopulation. However, she is also resourceful and has broken into cabins to raid food supplies in times when hunting prey has been unsuccessful.

Remains of reindeer left behind by hunters in the area have only exacerbated the issue by attracting Micha to the local settlements, and—as a wild animal—she will do whatever she needs to secure food for her cubs. The local council have suggested that Micha should be shot due to the risk she poses to local communities and her habit of raiding food stores, despite this being a natural survival behaviour.

Despite a petition released in objection to putting Micha down, her future remains on thin ice. With the rapid increase in global warming, there will likely be many more bears like Micha, posing threats to Arctic communities in attempts to survive. Whilst strictly securing anthropogenic waste and food sources might alleviate the issue, tackling the root cause of habitat loss is where the answer lies.

Featured Image: Hans-Jurgen Mager | Unsplash

Change (2022) ‘Save Frost the polar bear on Svalbard.’ Change. Available at: [Accessed November 13th, 2022]

Smith T., Derocher A., Mazur R., et al. (2022) Anthropogenic food: An emerging threat to polar bears. Oryx. First View, Pages 1-10.

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