Groundbreaking global bird study reveals how land-use changes are putting ecosystems at risk
New research shows human-driven habitat changes are stripping ecosystems of their natural safety nets
Human changes to landscapes around the world are reducing the vital services that wild birds provide, making ecosystems less stable and less resilient, new research has found.
A major international study published in Nature analysed data on nearly 3,700 bird species from 1,200 sites worldwide.
It found that altering habitats – through urban growth, farmland expansion and other land-use changes – cuts the number of species that perform essential jobs like pollination, seed dispersal and pest control.
Manchester Met academic and co-author on the paper, Dr. Alexander Lees has stressed the urgent need to protect this diversity of avian roles.
In natural ecosystems, these roles are shared by many species, creating a safety net called functional redundancy. This means if one species declines, others can fill the ecosystem service gap.
Using computer-based extinction simulations, the study revealed that land-use change removes this backup system, leaving ecosystems more exposed to future biodiversity loss.
Dr. Lees, Reader in Ecology and Conservation Biology at Manchester Metropolitan University, said: “Our findings challenge the notion that focusing solely on species richness is enough to safeguard ecosystem health”.
“The research highlights the urgent need to retain species that encompass a diversity of ecological roles, not just a high number of species.”
The study, in partnership with Imperial College London, used detailed data on bird traits – such as diet, body size, and beak and wing shape – and found that disturbed habitats are dominated by a few species with similar characteristics.
This simplification of ecological networks can lead to knock-on effects like slower forest recovery, less carbon storage and more crop pests.
Thomas Weeks, PhD researcher at Imperial and lead author on the paper, added: “The decline in bird diversity after land-use change is well known, but until now it was generally thought that enough different types of birds survived for those degraded ecosystems to continue functioning as required.
“Our analyses challenge that idea by showing that humans modify landscapes in a way that tends to remove all the slack in the system, meaning that any future environmental shocks can potentially cause a collapse of the essential services provided by wildlife.”
The study offers a new way to assess ecosystem fragility and guide conservation policy.
By focusing on the roles that species play, rather than just counting them, policymakers can better identify risks and protect ecological stability for both wildlife and people.