Animals may not know why humans are making themselves so scarce.

Lockdowns that have kept millions of people in their homes — and social distancing measures meant to slow the spread of the novel coronavirus — have brought clear skies, quiet streets and tranquil shores.

These are challenging times for humanity. But for many of Earth's other inhabitants, there's a silver lining.

Animals are not dramatically rebounding in the absence of humans, but they are timidly pushing their boundaries, with sika deer showing up outside their normal habitat in the park in Nara, Japan, wild turkeys showing up in a park in Oakland, California, and orcas venturing farther up Vancouver's Burrell Inlet than they typically do.

Thanks to the absence of cruise ships, dolphins have returned in greater numbers to the Italian port of Cagliari. And the presence of swans in the canals of Burano sparked a flurry of social media attention, even though swans are often seen in this small island in the greater metro area of Venice.

The bears and other animals of Yosemite have been having a "party" since the park closed on March 20, says a ranger and biologist who has been studying the park's bears for more than a decade.

In a Yosemite Facebook Live event, Ranger Katie talks about why Yosemite Valley is such a "paradise" for bears, regardless of the presence of humans, but especially in the spring.

There are typically so many humans and cars at this time of year that the bears have to pick their paths carefully to avoid them.

"Navigating that landscape, where there are lots of people, is difficult," she said. But that’s not the case now. "Bears are literally walking down the road to get to where they need to go, which is kind of cool."

For example, the video below shows a bear strolling through a meadow that would typically be filled with human gawkers.

And then there were the not-so-timid goats roaming around Llandudno, in northern Wales, helping themselves to the shrubbery:

"If anything, these times may serve as a reminder that animals have always lived in our area," Seth Magle, who directs the Urban Wildlife Institute at the Lincoln Park Zoo in Chicago, told The Guardian. "We may not think of our cities as a part of nature, but they are."

Regardless, this kind of reverse habitat-encroachment is comforting.

Nature hates a vacuum

When humans move out of a space, animals move in as these horses did in the aftermath of the Chernobyl nuclear accident. Kate Siomkina/Shutterstock

We've seen this kind of animal renaissance before, in the wake of very different catastrophes.

At the site of the former Fukushima Daiichi Nuclear Power Plant — where a 2011 meltdown forced the evacuation of thousands of people — animals like wild boar, macaques, and Japanese hares are flourishing.

And, more than 30 years after the Chernobyl disaster, Geiger counters still scold furiously at lingering radiation levels in the area — but wildlife have made an unlikely comeback.

It's not all good news for animals

While some animals are certainly relishing in the retreat, other animals that have come to rely on humans may actually miss us.

Like the macaques of Lopburi, Thailand. Spending their days loafing around the city's famed Phra Prang Sam Yot monkey temple, these primates have become all-too accustomed to human handouts. But with the coronavirus keeping tourists at bay — and handouts increasingly rare — they've gone all "Gangs of New York" on each other.

You can check out some of the mayhem in the video below:

"The fall in tourist numbers because of COVID-19 may have indeed brought about a shortage of food supply for them," Asmita Sengupta, an ecologist at the Ashoka Trust for Research in Ecology and Environment in India, tells The New York Times.

"Once they get used to being fed by humans, they become habituated to humans and even display hyper-aggression if they are not given food."

On the other hand, the goats in Wales don't mind. And, as more countries ground their citizens, experts suggest animals will take full advantage.

"I've seen what's happened in [other cities] and we've been thinking about what that means in the UK as well for wildlife," Martin Fowlie, media manager for the Royal Society for the Protection of Birds, tells Express.

"Since World War 2, UK wildlife has been in general decline, there are some species doing better, but on the whole, the majority of species have been doing less well."

But the hushing of cities and towns and countrysides, he adds, may not only benefit animals. Humans too may soon emerge from their homes with a new understanding of their relationship with the natural world. We might even look to preserve that kind of peace.