Human-wildlife interface conflicts rising with climate change

Conflicts at the human-wildlife interface are rising worldwide as the climate changes and habitats and behaviour alter

Research on the impacts of climate change often considers its effects on people separately from impacts on ecosystems. But a new study is showing just how intertwined we are with our environment by linking our warming world to a global rise in conflicts between humans and wildlife.

The research, led by scientists at the University of Washington’s Center for Ecosystem Sentinels, reveals that a warming world is increasing human-wildlife conflicts.

Lead author Briana Abrahms, a UW assistant professor of biology, said: “We found evidence of conflicts between people and wildlife exacerbated by climate change on six continents, in five different oceans, in terrestrial systems, in marine systems, in freshwater systems – involving mammals, reptiles, birds, fish and even invertebrates.

“Although each individual case has its own array of different causes and effects, these climate-driven conflicts are really ubiquitous.”

To identify trends, the team pored over published, peer-reviewed incidents of human-wildlife conflicts and identified cases that were linked specifically to the effects of climate change.

These include both short-term climate events – such as a drought – as well as longer-term changes.

Warming in the Arctic, for example, is leading to the loss of sea ice which has left polar bears short of food. They increasingly travel on land, sometimes entering human settlements and attacking people, as a recent incident in Alaska illustrates.

Wildlife behaviours

The new study shows that climate shifts can drive conflicts by altering animal habitats – like sea ice for polar bears – as well as the timing of events, wildlife behaviours and resource availability.

It also showed that people are changing their behaviours and locations in response to climate change in ways that increase conflicts.

Other examples of the effects of short- and long-term climate events include torrential floods in Tanzania led to more lion attacks after their usual prey migrated away from floodplains and wildfires in Sumatra, Indonesia – triggered by El Nino – that drove Asian elephants and tigers out of reserves and into human-inhabited areas, leading to at least one death.

Most cases of human-wildlife conflict linked to climate involve a shift in resources – not just for wildlife, but also for people.

A majority of cases on land also involved a change in precipitation, which will continue to be affected by climate change. Many resulted in human deaths or injuries, as well as property damage.

In 2009, for example, a severe drought struck the western part of Tanzania’s Kilimanjaro region. This reduced food supplies for African elephants, which in turn entered local fields to graze on crops – at times destroying two to three acres daily.

Local farmers, whose livelihoods were directly threatened by the drought, at times resorted to retaliatory killings of elephants to try to mitigate these raids.

Abrahms said: “Identifying and understanding this link between human-wildlife conflicts is not only a conservation issue; it is also a social justice and human safety issue.”

Patterns and trends

These types of conflicts are likely to rise as climate change intensifies, particularly as mass migrations of people and wildlife increase and resources shift. But, it doesn’t have to be all bad news.

Abrahms added: “One major motivation in studying the link between climate change and human-wildlife conflict is finding solutions.

“As we learn about specific incidents, we can identify patterns and trends – and come up with interventions to try to address or lessen these conflicts.

“We have effective drought forecasts now. So, governments can engage in fiscal planning for mitigating conflicts ahead of time. Instead of a ‘rainy day’ fund, have a ‘dry day’ fund.”

Success story

To Abrahms, one success story of note lies in the waters of the eastern Pacific. In 2014 and 2015, a record number of humpback and blue whales became ensnared in fishing lines off the California coast.

Research later showed that an extreme marine heat wave had pushed whales closer to shore, following their primary food sources.

California regulators now adjust the start and end of each fishing season based on climate and ocean conditions in the Pacific – delaying the season if whales and fishing gear are likely to come into close contact.

Abrahms concluded: “These examples show us that once you know the root causes of a conflict, you can design interventions to help both people and wildlife. We can change.”

The research is published in Nature Climate Change.

Image 1: A lone polar bear navigating sea ice, which this species uses to traverse vast distances in the Arctic to find food. A rapid loss of sea ice in northern latitudes has driven many polar bears onto land and into human settlements to scavenge. © Kathy Crane/ NOAA Pacific Marine Environmental Laboratory.

Image 2: Lions on a kill in the Okavango Delta, Botswana. When natural prey is scarce, such as during a drought, lions and other large carnivores are more likely to prey on livestock. © Briana Abrahms.