Shelter-in-place restrictions made mountain lions feel bolder near cities
SANTA CRUZ » Last spring, as COVID-19 infections spread rapidly and Californians were largely confined to their homes, mountain lions inched closer to the “urban edge” near Scotts Valley and Santa Cruz, new research out of UC Santa Cruz shows.
“There have been a lot of anecdotal reports of animals behaving differently during COVID,” Chris Wilmers, an environmental studies professor at UCSC and lead author on the study, said.
In Tel Aviv, jackals were reported hunting in daylight during the pandemic’s early days, as well as wild boars roaming through empty streets in Haifa, Israel.
But now, Wilmers and coauthors document in a research manuscript published online earlier this month in Current Biology that mountain lions traveled near more urbanized areas in Santa Cruz County, while traffic significantly declined as a result of regional coronavirus lockdowns.
“This is the first time we’ve seen a dramatic change in that behavior,” Wilmers said. “It shows the changes humans make and how they behave on the landscape can very quickly alter what wild animals are doing.”
The COVID-19 pandemic, and subsequent shelter-in-place orders, blunted the barrier that typically busier areas — filled with people, traffic and noises — present to mountain lions.
“What we saw pre-pandemic is that mountain lions were both afraid of people in their houses, but had an additional fear of cities because of all the extra human activity,” Wilmers said. “When a lockdown happened and the cities essentially shut down, they maintained their fear of housing on the landscape but they relaxed their fear of cities.”
Using tracking collars on six pumas, the researchers documented various habitats the cats made use of before, during and after Santa Cruz County’s shelter-in-place orders.
They then compared those to 2019 tracking data. The team also investigated changes in traffic levels across the Santa Cruz region.
Analyzing an Apple mobility database, the scientists found driving and walking trips reduced by 50%, by investigating the number of navigation requests on Apple maps.
The team also looked at potential changes in environmental factors that could impact pumas’ habitat selection such as topography, distance to water source and vegetation cover.
But the dip in commutes and traffic during the pandemic, the researchers found, was the major factor linked to pumas traveling near and in more urbanized areas, where they normally wouldn’t. Within days to weeks of shelter-in-place orders being implemented, the cats responded, changing
their usual habitat selection.
Take Bonny Doon, for example.
According to Wilmers, the mountainous coastal enclave is an area where occasionally pumas will visit, though still fearful of residential neighborhoods.
“The difference between Bonny Doon and the city of Santa Cruz is the city has a bunch of houses, buses, pedestrians and way more traffic,” Wilmers said. “It’s that sort of additional bustle of cities that disappeared, and we found mountain lions were sort of treating the city of Santa Cruz like they do Bonny Doon.”
Humans’ impact on
mountain lions isn’t new, Wilmers said. But the outsized effect of traffic on pumas’ behavior, is something the UC Santa Cruz scientist wants to dig into further.
“When people think of the impact of humans on ecosystems, they tend to think of habitat destruction, direct killing or poisoning, but what this research illustrates is the human mobility itself, separate from all those other things, might have an impact,” Wilmers said.
Mountains lions were listed as protected under California’s Endangered Species Act just last year. As transportation options have multiplied for humans over
the past century and particularly this past decade, Wilmers said, that has ripple effects.
Unpacking just what type of traffic is affecting mountain lions the most, Wilmers said, is an area of science he wants to explore.
“As humans become more numerous and we spread out over the landscape, we’re having more and more impact on mountain lions … if we’re to maintain viable populations of mountain lions into the future, we need to understand what are the things we do that are harmful and what are the things we do that are not a problem,” Wilmers said.