Animals Found To Encounter Each Other More Often When Living Closer To Humans

Human presence and impact on landscapes changes interactions and brings other animals closer together than they would in the wild.

Researchers at the University of Wisconsin-Madison used more than 2,000 camera trap photos from the Wisconsin Department of Natural Resources Snapshot Program to determine the spatial and temporal proximity of different animal species. In areas close to human disturbance, the time between seeing different species on cameras was very short, meaning they could interact more often when people were close.

The findings, published today in the Proceedings of the National Academy of Sciences , support the crowding hypothesis — the idea that human intervention eliminates the shared space and time between animals, herding them together and increasing the likelihood of mating with another school. The spread hypothesis predicts less interaction with certain animal species (eg, predators) due to human displacement.

"Squeezing works like a house party," said the study's lead author, Neil Gilbert, who completed his PhD in wildlife and forest ecology at UW-Madison earlier this year. "The more people you have at a party, the less rest you will have and someone will be hot on your heels."

Although they are not bothered by any human activity, especially scorpions and deer that breed near people, one thing is clear: Animals that try not to interact with people must be allowed freedom of movement.

"We've converted more than 40% of the Earth's surface to human use, urban landscapes, agricultural landscapes," said Ben Zuckerberg, study co-author and professor of forest and wildlife ecology at UW-Madison. "We can see this as quite significant habitat loss for many species."

Learning how this loss affects the animal's behavior and relationships can be difficult. Marking animals or small groups with tracking devices provides too limited a perspective to study interactions at the community level. But Snapshot Wisconsin, a community-based science initiative that employs volunteers to place camera traps on public and private land, has thousands of locations across the state and has produced millions of photos from continuous wildlife monitoring.

"Snapshot Wisconsin supports the DNR's decision to answer big questions like elk and deer," said Jennifer Stenglein, Snapshot Wisconsin research scientist and co-author of the study. "But when someone like Neal innovates with this large data set, it can push the boundaries of theoretical research."

Gilbert pulled nearly 800,000 animal photographs from the Snapshot Wisconsin archive and assigned each of the 2,000 camera locations within a three-mile radius to assess the amount of human disturbance, for example, in the forest. National and urban development of low latitude or intensive agriculture. . High level - based on NASA satellite images.

The researchers also divided the 18 observed species into groups of 74 pairs based on their likelihood of violent mating, ranging from low-antagonism pairs, such as skunks and rabbits, to high-antagonism pairs, such as deer and coyotes. He then measured the time between glances at different camera positions for each member of the pair per animal.

"Temporary separation is our goal," says Gilbert. "If the camera catches a squirrel and a coyote a minute later, those two animals are more likely to meet three weeks later than a squirrel and a coyote."

The couples in the study averaged 6.1 days between camera detections in low-noise landscapes, but 4.1 days between high-noise landscapes. Couples high in antagonism had, on average, much longer between intimate recognitions and partners than low antagonism, but the pattern persisted for each group: the closer they got to the human subjects, the shorter the time between interactions.

“It's a big question in ecology: How does human disturbance affect wildlife? We clearly see that they can change their relationship,” says Zuckerberg. "The next question is about the impact. Does this change the prevalence of the disease? Does it change the susceptibility? Does it affect things like deer-vehicle collisions?"

The researchers hope their work will help people understand the broader implications of changes in animal populations and habitat sizes.

"I hope it inspires us to think about the impact we have on these invisible aspects of biodiversity, like our bodies, even if it's just the animals in your backyard, in your neighborhood, in your neighborhood," Zuckerberg said.

More information: Neil A. Gilbert et al., The Spacescape of Human Disasters, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2206339119

Quote: Animals often meet when living with humans, accessed (Dec 23, 2022) Accessed Dec 24, 2022 https://phys.org/news/2022-12-animals-encounter-withhumans. html

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