Have you ever wondered how the birds chirping in your backyard are faring in our increasingly human-dominated world?
A new global study by a team of scientists has found that four out of five bird species are struggling to survive in habitats altered by human activities, even in seemingly remote areas.1
This research addresses the impact of human actions on bird populations.
Varied Responses to Human Presence
The researchers assessed bird populations across diverse landscapes, ranging from pristine habitats to heavily human-modified environments. They found that while some species thrive in human-altered landscapes, the majority struggle to adapt.
Lead author Emma-Liina Marjakangas, a community ecologist at Aarhus University, emphasized the vulnerability of threatened species and those with declining populations to human pressures.
Quantifying Human Influence
The study utilized data from the eBird citizen science project and the Global Human Footprint Index (HFI) to model the likelihood of each bird species occurring under different levels of human influence.(ref)
The HFI measures human pressure by considering factors like built environments, population density, night-time lights, agriculture, and roads.
Tolerance & Vulnerability
The findings show a clear contrast in tolerance levels among bird species. While 22% of the studied species could tolerate the most heavily modified environments, a small fraction (0.001%) was found exclusively in pristine habitats.
Importantly, species with declining populations displayed lower tolerance to human presence compared to those with stable or increasing populations.
Identifying Vulnerable Species
The study’s high precision allows for the identification of species most sensitive to human activity, such as the Great Snipe in Europe, the Nkulengu Rail in Africa, and Hume’s Lark in Asia.
While many bird species struggle to adapt to human-altered environments, not all are so sensitive. Surprisingly, some birds thrive in our midst. These feathered neighbors have found ways to coexist with humans, often using the resources and structures we create to their advantage.
“Some species can tolerate even the most intense human pressures on all continents,” Dr Emma-Liina Marjakanga, lead author of the study, observed. “Common Swifts are an example of such species that can be found breeding in urban areas all around the world.”
Regional Differences in Tolerance
Interestingly, the study noted regional differences in tolerance levels. Both Europe and North America exhibited higher proportions of human-tolerant bird species compared to Latin America and Africa.
This could be attributed to the loss of sensitive species or their adaptation to human-modified landscapes over long periods of human habitation in Europe.
The study helps us understand how different birds react to human activities. Some birds do well around people, while others need wild places to survive. This knowledge helps us make better plans to protect birds. We can focus on saving the most vulnerable species and reduce the harm humans cause to birds worldwide.
Source:
Read Next:
Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.