The majority of the world's bird species are unable to thrive in human-dominated environments, according to new research from the University of Helsinki in Finland and Aarhus University in Denmark.
The study found that 78% of the world's bird species struggle in those habitats with significant human pressure, after quantifying tolerance to breeding in human-dominated environments. These species are also more likely to have declining populations.
The team used eBird observations from between 2013 and 2021 for 6,000 bird species, and the Human Footprint Index, which holds data on built environments, human population density, light pollution, agriculture and road infrastructure.
Emma-Liina Marjakangas, a PhD student who led the study, said: "Threatened species, and species with declining populations, are less tolerant to breeding in human-dominated habitats. For example, the Fern Wren, a species occurring only in tropical forests of north-eastern Australia, is endangered, has a declining population and a very low tolerance to any human pressure."
Great Snipe is especially sensitive to human presence and requires pristine habitat to breed successfully (Anthony Bentley).
Mixed fortunes
Some species fare better than others, however, and can survive even in urban environments.
Marjakangas said: "Some species can tolerate even the most intense human pressures on all continents. Common Swifts are an example of such species that can be found breeding in urban areas all around the world."
The UN finalised the Kunming-Montreal Global Biodiversity Framework in December 2022, an agreement that aims to protect 30% of the Earth's land for conservation, although much of that land will already be significantly impacted by humans.
Aleksi Lehikoinen, senior curator at the Finnish Museum of Natural History, said: "This study enables us to identify species that are particularly sensitive to human activity and need more protected habitats to thrive, for example Great Snipe in Europe, Nkulengu Rail in Africa and Hume's Short-toed Lark in Asia. Conservation action to protect or restore habitat can then be targeted towards the species and locations that need it most."
According to the paper, published in Global Ecology and Biogeography, a higher proportion of species in Europe and North America are tolerant of human activities than Latin America, Asia and Africa. This may partly be explained by Europe having been altered by humans for millennia, meaning some species will have already vanished while others had a long time to adapt to slower pre-industrial changes to habitats.
Reference
Marjakangas, E-L, Johnston, A, Santangeli, A, and Lehikoinen, A. 2024. Bird species' tolerance to human pressures and associations with population change. Global Ecology and Biogeography, DOI: 10.1111/geb.13816.
