Washington [US]May 23 (ANI): A team of researchers led by scientists at the University of California – Santa Cruz analyzed data from 3,212 camera traps to show how human disturbance could change the makeup of mammal communities in North America.
The study, published in Global Change Biology, builds on the work of the previous team who examined how animals in the Santa Cruz Mountains respond to human disturbance. For example, local sightings have shown that species such as cougars and bobcats are unlikely to be active in areas where humans are present, while deer and woodlice become more daring and energetic. But it is difficult to generalize these findings to larger geographic areas, as interactions between humans and nature are often unique at the regional level.
To get a feel for which mammalian species are best equipped to coexist with humans, the team combined data from their own camera traps with data from researchers in the United States, Canada and Mexico. This has enabled them to track 24 species in 61 regionally diverse camera trap projects for larger trends as they arise.
“We’ve been very interested in how human disturbance has affected nature for a long time, and we thought it would be interesting to see how animals in general react to similar human pressures in North America,” said Chris Wilmers , an environmentalist. Studies professor and director of the Santa Cruz Puma Project, who, along with lead author Justin Suraci, is lead author of the article.
The team was particularly interested in understanding how mammals respond to different types of human conditions and whether those responses relate to characteristics of the species, such as body size, diet, and number of young. Overall, the article found that 33% of mammalian species reacted negatively to humans, meaning they were less likely to appear in places of high disturbance and were less active when present. while 58% of the species were positively associated with the disease.
To take a closer look at these trends, the team split their findings into two different types of human disturbance. One of these was the impact on human development: the things people build, like roads, houses, and farmland. The other was the mere presence of humans, including activities such as entertainment and hunting, as fear of humans can change an animal’s behavior and the use of space.
By comparing continental data from camera trap locations with different levels of human development, researchers found that grizzly bears, lynxes, wolves and wolverines are generally less likely to be found in more developed and less developed regions. active when visited. Elk and martins were also less active in areas with a higher development footprint.
Meanwhile, raccoons and white-tailed deer previously stayed in more developed areas and were more active in those spaces. Moose, deer, striped skunks, red foxes, bobcats, wolves, and cougars were unlikely to be found in changing landscapes, but they were more active in these areas.
Some species that repeat in more developed regions may benefit life in those places, but the study’s lead author Justin Suracy, senior scientist at Conservation Science Partners and former postdoctoral fellow at the University of California, Santa Cruz says that’s not necessarily the case. the case. While raccoons can thrive in developed regions by finding food in our litter boxes and avoiding predators, a higher rate of cougar activity in the same places could mean something entirely different.
“Not because these developed areas are really good for Puma,” Soraci said. “It is likely that the reason is that the camera traps are placed on a single track that a poor cougar could use to make their way through a very advanced landscape.” In other words, some of the animals in the study may be active or increasingly present on cameras close to human development simply because there is little natural habitat left.
However, some traits emerged in the species as clear livelihood advantages within its developmental footprint. In general, the smaller, faster reproducing mammals, as well as the general diet, are the most positively associated with growth. The researchers speculated that they might find similar results by comparing camera capture data based on the level of human presence, but in fact, both positive and negative responses to the species’ human presence have been seen across the spectrum of body size and diet.
Elk were less likely to survive in areas frequented by humans, and moose, mountain goats, and wolverines were less active in these habitats. In contrast, bighorn sheep, black bears and wolverines were more likely to be found in areas frequented by humans, while mule deer, bobcats, gray foxes, cougars and wolves were more active.
One trend that may influence these results is the growth of outdoor recreation, increasing the presence of people in remote and wild landscapes. Research results may indicate that most mammals are willing to withstand some level of human recreation to survive in better habitats, and may instead increase their nocturnal activity to avoid humans. Some animals may even benefit from walking trails and fire trails as easy travel paths.
But the study also clearly showed that there was a limit to the extent to which humans could influence animals. Even in species that were more active or more likely to be found in humans or in developed regions, these effects peaked at low to moderate levels of human disturbance and then began to decline beyond these thresholds. . Red foxes were the only animals in the study to be even more active or to exhibit moderate to high levels of human disturbance.
Ultimately, most species have something to lose and gain from being close to humans, and understanding how the costs outweigh the benefits for each species will be important in maintaining suitable habitats that support the diversity of the species. future mammal populations. Suraci says this is perhaps the new newspaper’s most important contribution.
“From a management perspective, I think the thresholds we’re starting to set will be really relevant,” he said. “This can help us recognize the amount of habitat already available for recolonization or reintroduction of species and, hopefully, allow us to coexist more effectively with wildlife in human-controlled landscapes.” (Ani)