The more people expand into previously natural areas, the more wildlife and humans step on each other’s toes, leading to more interactions that may result in conflict. This includes national parks where people flock to recuperate and enjoy the outdoors.
Writing in Frontiers in Conservation Science , researchers in the UK have examined which animals are most likely to be involved in aggressive encounters – defined as potentially dangerous situations between humans and animals – during which activities they’re most likely to happen, and which activity-animal pairs hold particular risk.
“We found low‑impact activities were associated with the highest frequency of aggressive encounters, regardless of species,” said first author Holly Landles, a researcher at the University of York.
“Now we can point to precise high‑risk pairings, such as elk visiting townsite areas or mule deer encountered during dog walking,” added senior author Dr Shashank Balakrishna, a biologist at the University of York. “This allows park managers to focus resources, signage, and education where they are most needed.”
The researchers drew on a database of almost 3,500 reported incidents between 2010 and 2023 recorded by Parks Canada, selecting incidents involving humans and elk, black bears, grizzlies, coyotes, and mule deer. These species were chosen because they were involved in aggressive encounters most often in the dataset the team worked with. Seven types of activities park visitors were engaging in were included in the risk analysis: low-impact activities (hiking, wildlife observation), extreme sports (kayaking, climbing), animal-involved activities (dog-walking, horseback-riding), camping, transport-related activities (road cycling), townsite activities (golfing), and park operations.
Results showed that species mattered, but so did the type of activity and animal-activity combinations. Elk were involved in around 62% of all aggressive encounters, followed by grizzly bears (14%), black bears (13%), mule deer (7%), and coyotes (3%).
“Each species occupies a different ecological role, so they perceive human threat differently,” Balakrishna pointed out. “Elk sometimes avoid humans, but at other times use human presence as refuge from predators. This unpredictability may explain why they top the list for aggressive encounters.”
On the activity side, low-impact activities were most associated with aggressive encounters, making up around 25% of incidents, followed by townsite activities at 22%, which may be particularly risky due to the unfamiliar stress wildlife faces in more urban environments. Adventure sports accounted for just over 4%.
When combining activity type with species, the researchers found certain animals were more likely to be encountered during certain activities. Elk, for example, were involved in over 73% of run-ins happening at townsites and in 57% of incidents recorded during adventure sports.
Grizzly and black bears were most often encountered during low-impact activities, making up 45% and 43% of these encounters, respectively. This may be because they are particularly prone to reacting aggressively to surprise encounters, which are more likely to happen during quiet activities in forested areas.
Mule deer and coyotes were most often involved in aggressive encounters in townsite settings. “Mule deer also showed more aggression during activities involving pets, likely because dogs resemble their natural predators,” said Balakrishna.
This, however, doesn’t mean that the activities examined here should be avoided altogether during park visits. “We recommend simple precautions,” said Landles. “Announcing yourself is a good idea, especially for grizzly bears. Taking whistles, talking, or hiking in larger groups can help, too. Keeping leashes short when large herds are present is simple but effective.”
In addition, park visitors can check park information, including bear or herd sightings and trail closures, on the day of their visit.
The researchers said their data only included incidents reported to park staff, so the number of aggressive encounters – particularly those where people weren’t harmed – may be underestimated. There also was some data that wasn’t available, such as animal sex, how many people were involved, or how long they spent on the activity, so the findings don’t show cause-effect relationships.
Yet they are useful for identifying what future studies need to examine, said the authors. In addition, the results provide pointers which park rangers can follow in national parks worldwide. In many parks, recommendations like dynamic trail ratings and improved signage have already been implemented. Now it is on park visitors to act responsibly, the team said. For example, abiding by trail signage – also in remote areas – can help decrease the number of interactions that might result in situations in which humans, animals, or both suffer.
“Ultimately, both people and wildlife lose during aggressive encounters,” concluded Landles. “Our findings helps us understand real patterns behind these encounters so we can reduce their frequency and help people and wildlife coexist more safely.”
Frontiers in Conservation Science
Data/statistical analysis
Aggressive encounters with large mammals vary by recreational activity type in Canadian national parks
2-Jul-2026
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.