Birds returned to U.S. cities during COVID-19 closures


  • Many animals have used the first months of 2020 COVID-19 closures to occupy places once dominated by humans.
  • A study published in Science Advances confirmed that the number of birds in North American cities increased significantly in the spring of 2020.
  • Below, experts explain how we can decrease our activity in cities to make them more attractive to birds.

Of wild goats in a Welsh town with endangered turtles that have nested on deserted beaches, numerous animals used the first months of the coronavirus confinement to get comfortable in places normally dominated by humans.

Now, a study published in Scientists progress confirms that the number of birds in North American cities affected by the pandemic really increased in the spring of 2020, education scientists an important urban message biodiversity.

“We can make cities more attractive to birds by reducing our activity,” lead study author Dr. Michael Schrimpf of the University of Manitoba in Canada told EcoWatch.


Human development and activity obviously have an impact on birds and other animals, but scientists do not often have the opportunity to separate the impacts from one another. Roads or airports destroy habitat during construction, but their continued use results in noise and air pollution that can further disrupt species.

“We’ve never really had the opportunity to test on such a large scale what happens if you still have all of this infrastructure, all of these things, but you’re just downsizing,” Schrimpf said.

Enter the new coronavirus. During the first months of containment in the spring of 2020, human activity slowed to a degree unprecedented in modern history. This is something the study authors called “anthropause,” and it essentially defined the conditions for a real-world experience.

The locations of an active animal tracking sub-sample through the “anthropouse”.

Image: Yale

The quietest months of the containment period in North America coincided with the spring migration season from March to May. This allowed the research team based in Canada and the United States to compare the number of birds spotted in urban areas during this season with counts from previous years.

To do this, the researchers used data from eBird, a citizen science project run by the Cornell Lab of Ornithology that allows birders to report their sightings.

“Basically they go out, they walk around or stay in one place, record how many different bird species they see, and then submit it to the program in what’s called a checklist,” explained Schrimpf.

The researchers looked at eBird data for 93 counties in the United States and Canada that contained urban areas, comparing the numbers for 2020 to those for the spring of 2017 to 2019. They looked at how the number of birds has changed. during the pandemic through five indices of reduction in human activity. :

2. The overlap between peak containment and peak migration period

3. Distance from main roads

4. Distance from international airports

They also made sure to control the fact that there may have been more people watching the birds during the pandemic. Ultimately, they selected 4,353,739 individual bird sightings from 88,846 checklists.

What they found was that 80% of the species they examined (or 66 out of a total of 82) saw their numbers change during the pandemic in urban areas, near roads and airports, and in counties where the peak of containment coincided with the peak of migration. Usually their number increased. In fact, the number of species was 14 times more likely to increase than decrease for all indices. This tells scientists that human activity really does make a big difference.

“The fact that the birds really responded massively by showing up more in all of these places when the activity was declining means that we now have a much better idea of ​​the magnitude of the effects of our activity,” said Schrimpf.

Unanswered questions

The results gave researchers a clue to understanding how to attract birds to cities.

“Our results indicate that human activity is affecting many birds in North America and suggest that we may make urban spaces more attractive to birds by reducing traffic and mitigating disruption caused by human transport after exiting. pandemic, ”the study authors wrote.

However, there is still a lot that researchers don’t know. The first is whether the birds returned to their original haunts when human activity resumed.

“In the years to come, we can hopefully look back and see whether or not things have returned or not right away or whether or not there have been more lasting changes,” said Schrimpf.

The second is whether this change of location was actually good for the birds. Until researchers can look at the numbers for the 2020 breeding season, they won’t know the answer. It’s possible that birds that chose a breeding site that appeared calm in the spring of 2020 might have had a nasty surprise when traffic and noise increased later in the year.

It is also possible that the suddenly quiet roadsides or city parks presented what Schrimpf called an “ecological trap”, a place that seemed appropriate due to a lack of traffic but still presented other dangers like the predation by domestic cats.

“Birds going through their migration period face many threats and we don’t know if this increased use of more urban places near roads, near airports was actually better for birds,” Schrimpf said.

Citizen science

Still, the pandemic may have motivated more people to pay attention to the birds in their area and therefore be interested in making the kind of changes that would keep them around.

“When people know something and experience it, they’re usually more interested in protecting and caring about it,” Schrimpf said.

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He also expressed gratitude to the citizen scientists who had paid attention to urban birds before the pandemic, without whom the study could never have been completed. That said, it’s never too late to start listening and birding in your neighborhood, and perhaps submitting your own eBird checklist.

“Not only do I think it gives us data that we could use to understand the world, but hopefully it also gives people a greater appreciation for the world around them,” he said.


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