Photo by Sumeet Mishra on Unsplash
In a groundbreaking study during Covid-19 lockdowns, researchers from Tel Aviv University and Hebel Normal University used acoustic recorders to monitor the behavior of urban birds in the absence of human activity. The study focused on the hooded crow, rose-winged parakeet, and Prinea in Tel Aviv, revealing that human-dependent birds like crows and parakeets decreased their activity in empty parks; the shy prinia, on the other hand, increased its presence. The findings highlight the impact of human presence on urban wildlife and the importance of urban parks in providing habitats for various species. The study, which analyzed nearly 400,000 recordings over 3,200 hours, provides valuable insights into how birds adapt to changes in human activity, with human-dependent species following people to residential areas and the Prinia thriving in the absence of humans in parks.
Lockdowns Create Unique Study Environments
During the Covid-19 lockdown, many projects were begun that were often put on the back burner. There was time to use, and the lockdown prevented much of its use in the normal ways, usually outdoor activities. While many things were achieved during the Covid lockdown, they were largely done inside. Scientific communities became interested in how animals used to being in the company of humans, were impacted as humans moved indoors. This was especially true in urban settings. This time (start to finish of Covid lockdown) afforded researchers a rare opportunity to see how some animals reacted when the human element “disappeared.”
A combined study with Tel Aviv University (Israel), Hebel Normal University (China), and five researchers set out to monitor several species, including the hooded crow, the rose-winged parakeet, and the prinea. All these birds are quite adapted to human activity. In fact, the parakeet has grown to become dependent on humans for food. The prinia, an urban bird that eats insects, is typically shy of human activity.
Researchers used recorders placed around Tel Aviv to create acoustic recordings allowing for non-human interaction. 17 recorders were randomly placed in parks, residential areas, and along roads where humans were more active. What was discovered were realities that found dependent birds with decreased activity in empty parks, and the shy Prinia with increased activity in those same empty parks. The resulting discoveries were important for researchers to recognize the value of urban parks and how wildlife acts when humans are not around.
A Surprising Change In Birds’ Habits
Previously, such studies were undertaken with watchful eyes. The concern had become that with humans nearby, even their close presence would trigger activity by those creatures that like humans. The hidden recorders with zero human interference (the first of its kind) provided a realistic reality – absence. One interesting feature was that the birds became involved in the opposite of their usual habits, and other creatures who usually came out at night were more apt to explore the parks during the day. Interestingly, it was determined that the human-exploiting birds moved to where human activity was more likely, and the Prinia thrived without humans moving about.
Almost 400,000 recordings were evaluated (approximately 3200 hours’ worth) over the period of the mandated lockdowns. In the residential areas where human activity increased, human-dependent birds were now found more often, that is, where the food was more likely to be. In the empty parks, the prinia were found to be 12% more active than they had been in the past – still shy but less so. The crow became 50% less seen, and the parakeet was 90% less available.
Such studies are interesting as they show how creatures like the birds in this study will react to the absence of humans. While all the birds had adapted to human activity, it was the crow and the non-native parakeet that had become “friends” to humans, following them to where the humans were most likely to be.
You can read the study itself (here) for a more in-depth look at how it took shape and its fascinating takeaways.