How were birds affected by human activities during the COVID-19 lockdowns? Researchers started to worry about the future of long-term animal monitoring projects at the start of the COVID-19 epidemic.
Pigeons flying around the the infrastructure of a pigeon keeper, in Wichelen, Tuesday 02 August 2022. Last weekend, 20,000 racing pigeons went missing after an international race from Narbonne, France. Pigeon racing is the sport of releasing specially trained homing pigeons, which then return to their homes over a carefully measured distance. The time it takes the animal to cover the specified distance is measured and the bird's rate of travel is calculated and compared with all of the other pigeons in the race to determine which animal returned at the highest speed. Keeping, breeding and 'playing' with race pigeons is a popular hobby in Belgium. Belgian breeders are well known for the high performance of their animals.Photo by NICOLAS MAETERLINCK/BELGA MAG/AFP via Getty Images
When Lockdowns Started
During the first spring of lockdowns, the Breeding Bird Survey of North America was suspended, and academics questioned whether other venerable citizen science initiatives would also take a break. Or that individuals would cease going out of their way to upload images to websites like iNaturalist.
However, Olivia Sanderfoot, working on her PhD at the University of Washington, was determined to keep studying birds in the region. She questioned how one could stay active in the community even in trying circumstances. In reality, she used the lockdowns as a chance to research how humans' presence or absence affects birds in cities.
She was the study's lead author, and her colleagues consulted the birding community to learn where individuals were sighting birds during the pandemic lockdowns. The study was published in Scientific Reports. Additionally, more than 900 volunteers signed up after hearing about the project in the national media.
When the pandemic hit, Sanderfoot and her team used information from Google's Community Mobility Reports to monitor how many people were moving about in the study area. Compared to a pre-pandemic baseline, the reports displayed the percentage change in human mobility. She claimed that the spring of 2020 saw a significant decrease in human mobility.
The study discovered that three-quarters of the 46 typical backyard birds tracked in suburban and urban areas of the Pacific Northwest were associated with human mobility when comparing human movement data to bird sightings. Black-capped chickadees (Poecile atricapillus), great blue herons (Ardea herodias), downy woodpeckers (Picoides pubescens), and Wilson's warblers were some of the species that displayed the strongest associations (Cardellina pusilla).
Because fewer people were moving about in cities, it's possible that many of these animals made use of the available space there.
But interestingly, she claimed, human activity had varied effects on bird detection-it wasn't always detrimental.
For instance, during the lockdowns, species like the northern flicker (Colaptes auratus), black-capped chickadee, and great blue heron were less likely to be found in areas with higher human mobility. In contrast, American goldfinches (Spinus tristis), tree swallows (Tachycineta bicolor), and mallards (Anas platyrhynchos) were more likely to be found in these areas. This, according to Sanderfoot, demonstrates that not all species shun humans in the same way.
Important Implications
These results imply that some bird species may have abandoned densely urbanized regions and may have increased their appearance in green spaces like parks and backyards observed by volunteers when closure restrictions started to loosen and human disturbance increased. She added that this demonstrates how crucial it is for cities to have green space.
Additionally, they discovered that during the peak of the lockdowns, only half of the species they included in the study had strong associations with ecological characteristics like land use or canopy cover. During lockdowns, "birds may have been able to use a larger range of habitats," Sanderfoot suggested.
Potential Future Usage of the Data
She added that this knowledge might be beneficial even after the pandemic. "This study, in my opinion, is an intriguing exploratory review of the factors influencing bird site use in our cities. It highlights the intriguing notion that birds are susceptible to disturbance daily. It would imply that the same species-specific interactions might endure after humans restart our pre-pandemic behaviors.
For Sanderfoot, involvement in the community was an added advantage. She claimed that involving birders in the project's community science initiative was its most satisfying aspect.
