- A review of 49 studies reveals that a variety of weather-related phenomena that are likely to become increasingly common due to climate change may increase human-wildlife conflict.
- The most commonly reported conflict outcomes were injury or death in people (43% of studies) and wildlife (45% of studies), and loss of crops or livestock (45% of studies). Many documented cases are occurring in the tropics, with animals such as Baird’s tapir (Tapirus bairdii) in Mexico, and elephants in Africa and Asia, increasingly coming into conflict with local communities.
- The impacts of climate change on human-wildlife conflict may especially affect vulnerable human populations, particularly when combined with pressures that limit mobility and flexibility in humans and animals. These stressors should be minimized where possible, researchers suggest.
- A better understanding of the climatic drivers of human-wildlife conflict could help prevent or alleviate conflicts. Predicting the onset of extreme weather events such as droughts, and proactively responding with temporary measures to protect animals and people, could be one effective solution, as could sharing information on how to avoid the hazards of wildlife conflict.
READER ADVISORY: This story contains images of dead animals that some viewers may find disturbing.
Wherever people live in close proximity to animals, conflicts will inevitably occur. And whenever environmental conditions change, populations expand or resources become restricted, a natural balance that evolved over millennia may be disturbed, and conflicts will often escalate.
This happens as humans encroach on animal habitat, where wildlife populations recover from past declines, or, increasingly, where the impact of a changing climate escalates the frequency, duration and intensity of extreme weather events.
When wildlife biologist Briana Abrahms of the University of Washington in the U.S. did the fieldwork for her Ph.D. in Botswana’s Okavango Delta, she heard accounts of how its wild carnivores were more frequently attacking livestock — and the occasional person — during times of drought. Later, when she moved to the U.S. National Oceanic and Atmospheric Administration to study whales, a massive heat wave caused a shift in whale feeding behavior that quintupled the number of whales that got entangled in fishing nets.
“Two totally different things,” she recalls, “but what was similar in both situations is that the underlying driver was an acute climate event, a prolonged drought or a marine heat wave, that changed the relationship between people and animals. That made me wonder how widespread this might be.” The result is a new paper authored by Abrahms and a team of researchers in the journal Nature Climate Change that provides an overview of 49 studies that suggest a link between increased human-wildlife conflict and the effects of extreme weather or climate change.
“The biggest surprise was just how ubiquitous [that connection] is,” she says, “whether in the ocean or on land, in the Arctic or in Southern Africa, it’s really globally widespread.”
“This is an important paper,” says Philip Nyhus, a conservation scientist at Colby College in Waterville, Maine, U.S., who has worked on human-wildlife conflict across Asia but was not involved in this study. “Human-wildlife conflict is already one of the most important challenges in conservation. As the world changes, we need to understand how our interactions with wildlife will change.”
In more than half the studies Abrahms and her colleagues analyzed, animals were found to be using parts of the landscape in which they would rarely be found otherwise, as they responded to heat waves, wildfires, extended drought, excessive rainfall, or other extreme events. In a typical case, Baird’s tapirs (Tapirus bairdii) on the Yucatán Peninsula in southeast Mexico were found roaming around local villages during severe droughts to find water, which also makes them more likely to feed on crops.
In unusually dry years, like 2019, “we recorded more frequent complaints from agricultural producers about wildlife like tapirs feeding on crops,” says Fernando Contreras-Moreno of WWF México, who co-authored a study that was included in Abrahms’s analysis, but was not involved in the Nature Climate Change paper. “This year, we have conditions very similar to 2019. The aguadas, the natural water bodies of the Maya Forest, are dry, so we are expecting a repetition of these alarming circumstances,” notes Contreras-Moreno.
To ease these conflicts, WWF has collaborated with the Calakmul Biosphere Reserve and the United Nations Development Programme to install artificial water troughs for wildlife in the region. Since 2020, these have been monitored with camera traps to study how and when wild animals use them.
Trouble around Tsavo
Joseph Ogutu, a biostatistician at the University of Hohenheim, Germany, who was involved in a number of studies on human-wildlife conflict in Kenya that were included in the Nature Climate Change paper, agrees that as climate change causes more pronounced droughts, artificial water sources may be a good way to keep animals away from human habitation.
But he also warns of unforeseen consequences: “In Kruger National Park in South Africa, where I’ve also worked, areas that are remote from water were used by rare antelopes like sable and roan to escape predation by lions. The [artificial] water points attracted zebras, and then lions came in, also killing the antelopes. So some water points had to be closed again.” Together with colleagues at the Kenya Wildlife Service, Ogutu recently analyzed more than 39,000 cases of human-wildlife conflict in the Greater Tsavo Ecosystem surrounding Tsavo East and Tsavo West national parks.
More than half of the cases, recorded by the Community Wildlife Division of the Kenya Wildlife Service between 1995 and 2016, involved elephants. Some had damaged crops or property, others attacked people; there were 363 incidents in which humans were killed, and many more in which the elephant did not survive. Other species that often ran into trouble with humans were baboons and monkeys (4,480 incidents), buffalos and hippos (2,432 and 1,497 incidents, respectively) and lions and hyenas (1,645 and 925 incidents).
Next on the conflict list was a less-than-usual suspect: “Snakes were involved in almost 1,500 incidents,” says Ogutu, “and these are also more common during droughts, as snakes may enter people’s houses looking for water, and some of them are venomous.”
In recent years, many drought-related problems, including human-wildlife conflicts, have been getting worse, he adds. “Something definitely is changing. Droughts are becoming more frequent and more intense, and climate change is increasing the unpredictability and uncertainty of the weather.”
He adds, however, that climate change isn’t the only issue. “In my thinking, at least in East Africa, it is the interaction between human population, human activities and climate change that has the strongest impact. Wildlife and pastoralists used to cope by being mobile and flexible. But because human numbers have gone up, and the number of human settlements and infrastructure has increased, this is becoming more and more difficult. We really need more space for wildlife to roam.”
Creative problem solving
The fences that often rise up in response to conflicts, both among humans and between humans and wildlife, may be making some of these problems worse, Ogutu notes. The study around Tsavo revealed that elephant attacks on humans, for example, are no less common in areas with many fences, as both elephants and humans tend to make their way through the barriers regardless. Fences “are often not a good solution,” Ogutu says.
Abrahms suggests that, instead of relying on permanent barriers, more dynamic measures could work better. She cites the recent response to increased whale fishing gear entanglements as potentially providing inspiration. “The state of California now explicitly considers the climatic and oceanic conditions to assess the risk of whales becoming entangled when making decisions on whether to open or close the fisheries,” she explains, noting that humanity’s improved ability to predict extreme weather, combined with the implementation of temporary proactive measures, may provide a positive way forward.
Further research demonstrating a firm link between climate change and human-wildlife conflict could also justify some percentage of the loss and damage payments made to vulnerable nations for climate adaptation to be used locally in the management and compensation of human-wildlife conflict. Loss and damage payments made to traditional communities that are increasingly coming into contact with climate-stressed animals could immediately benefit local livelihoods and biodiversity alike, says Abrahms. “I think there may be win-wins when it comes to climate change adaptation.”
Humans changing their ways
Relatively few of the studies analyzed by Abrahms and her team looked at how humans altered their behavior in response to extreme climate events. “A lot of the literature is focused on the wildlife side of things, so I would be interested to see more research looking at how climate change is affecting human behavior,” she says. However, she did track down some studies that hint at such changes.
In South Africa, a heat wave associated with El Niño caused a 350% increase in shark bite incidents, presumably because conditions in the ocean forced sharks to forage closer to shore, while the excessive heat probably drew more people to the beaches to swim.
Another study reported how in the extensive Sudd wetland of South Sudan, there are more crocodile attacks on humans and their livestock during the dry season, as people spend more time near the streams to bathe and collect water, and herders cross the water on foot to find fresh forage for their cattle. John Benansio of the Alliance for Environment and Rural Development in Juba collected witness reports for 23 attacks on humans between 2018 and 2020, all of them fatal, and 355 on livestock.
And, he notes, things will likely become worse. “The dry season is getting longer,” Benansio says. “When I was young, rainfall started in March, now it sometimes only starts in May.” During the long civil war in the region, few people lived in the wetland. “Now many people have returned.”
Exacerbating the human-crocodile conflict is the fact that cultural knowledge on how to avoid attacks is less widespread than it used to be. “Experienced people say they notice a crocodile by its smell, or if they see small fish jumping out of the water,” he explains. “New people who don’t understand these things are at higher risk … We need an initiative to inform people and install water points for them as well,” he says. Sharing information on crocodile behavior and dry season risks could help, especially as human populations continue growing and encroaching more on wildlands.
Scientists like Benansio could be part of the solution, talking regularly to people with different levels of wildlife experience in settlements and fishing camps across the region. As some wildlife populations bounce back due to conservation, even as human populations continue increasing, people like him could become increasingly important in restoring and creating cultural knowledge of how to behave around wild animals, and suggesting techniques to help protect people’s lives and livelihoods.
“Many younger people may have less experience with wildlife,” notes Ogutu, “but the older people, who have lived with wildlife for most of their lives, know a great deal about this. They should be empowered to educate us, so that we can understand how to respond. They are the ones who know.”
Banner image: Nile crocodiles (Crocodylus niloticus). In the Sudd wetland in South Sudan, deadly attacks by Nile crocodiles on humans are common and may increase if climate change extends the duration of the dry season. Image by Rod Waddington via Flickr (CC BY-SA 2.0).
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Citations:
Abrahms, B., Carter, N. H., Clark-Wolf, T. J., Gaynor, K. M., Johansson, E., McInturff, A., … West, L. (2023). Climate change as a global amplifier of human–wildlife conflict. Nature Climate Change. doi:10.1038/s41558-023-01608-5
Nyhus, P. J. (2016). Human-wildlife conflict and coexistence. Annual Review of Environment and Resources, 41(1), 143-171. doi:10.1146/annurev-environ-110615-085634
Pérez-Flores, J., Mardero, S., López-Cen, A., & Contreras-Moreno, F. M. (2021). Human-wildlife conflicts and drought in the greater Calakmul Region, Mexico: Implications for tapir conservation. Neotropical Biology and Conservation, 16(4), 539–563. doi:10.3897/neotropical.16.e71032
Mukeka, J. M., Ogutu, J. O., Kanga, E., & Røskaft, E. (2020). Spatial and temporal dynamics of human-wildlife conflicts in the Kenya Greater Tsavo Ecosystem. Human–Wildlife Interactions, 14(2). doi:https://doi.org/10.26077/bf21-497e
Chapman, B. K., & McPhee, D. (2016). Global shark attack hotspots: Identifying underlying factors behind increased unprovoked shark bite incidence. Ocean & Coastal Management, 133, 72-84. doi:10.1016/j.ocecoaman.2016.09.010
Benansio, J. S., Demaya, G. S., Dendi, D., & Luiselli, L. (2022). Attacks by Nile crocodiles (Crocodylus niloticus) on humans and livestock in the Sudd Wetlands, South Sudan. Russian Journal of Herpetology, 29(4), 199-205. doi:10.30906/1026-2296-2022-29-4-199-205
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