European Bird Populations Threatened by Intensive Farming, Study Finds

Eliminating habitats and prey and the increasing use of fertilizer, pesticides and herbicides have contributed to the dramatic decrease in Europe’s birdlife.

The common kingfisher (Alcedo atthis)
By Paolo DeAndreis
Jun. 13, 2023 13:55 UTC
The common kingfisher (Alcedo atthis)

Intensive farm­ing in Europe might affect bird species and pop­u­la­tion num­bers more than pre­vi­ously thought.

A new study pub­lished in PNAS, a peer review sci­en­tific jour­nal of the U.S. National Academy of Sciences, con­sid­ers a mas­sive amount of data retrieved in 28 European coun­tries across 37 years.

Our results sug­gest that the fate of com­mon European bird pop­u­la­tions depends on the rapid imple­men­ta­tion of trans­for­ma­tive change in European soci­eties, and espe­cially in agri­cul­tural reform.

A team of inter­na­tional sci­en­tists assessed 170 com­mon bird species in 20,000 dif­fer­ent sites and researched how those species reacted to four sources of anthro­pogenic pres­sure: urban­iza­tion, change in for­est cover, tem­per­a­ture change and agri­cul­tural inten­si­fi­ca­tion.

In the area being con­sid­ered, researchers found that farm­lands’ birdlife dropped by 60 per­cent in the four decades from 1980 to 2016.

See Also:Olive Grove Expansion Threatens Endangered Bird Species in Spain

The researchers’ goal was to estab­lish the extent of the bird pop­u­la­tion decline and to uncover the rela­tion­ships among those four dif­fer­ent pres­sures and their com­bined impacts on birdlife. Intensive farm­ing was sin­gled out as the most impact­ing pres­sure.

European Union offi­cial data show that almost 40 per­cent of the E.U. is ded­i­cated to agri­cul­ture. According to the researchers, such exten­sive farm­land helps explain its poten­tial impact on birdlife.

The new research mea­sured inten­sive farm­ing as the cover of farms with high input of pes­ti­cides and fer­til­iz­ers.

Among the rea­sons for the sharp decline in birds pop­u­la­tion as inten­sive agri­cul­ture expands, there is the sig­nif­i­cant drop in avail­able prey, such as insects,” Federica Luoni, a bio­di­ver­sity man­age­ment and pro­tec­tion sci­en­tist at the Italian Association for the Protection of Birds and Nature (Lipu), told Olive Oil Times.

Previous research, such as a recent study in Germany, showed how in the last 20 years, there were areas where the insect pop­u­la­tion dropped by 80 per­cent,” added Luoni, who is not directly involved in the new research.

Crucial insects such as pol­li­na­tors are directly affected by the wide­spread use of chem­i­cals in agri­cul­ture.

We are reach­ing the point where some are plan­ning man­ual or mechan­i­cal pol­li­na­tion oper­a­tions where the wild insect pop­u­la­tion can­not guar­an­tee pol­li­na­tion any­more,” Luoni explained.

According to the study, inver­te­brates are a cru­cial part of many bird species’ diets, espe­cially at spe­cific stages of their devel­op­ment. Of the 170 species con­sid­ered, 143 depend on insects dur­ing breed­ing.

The researchers wrote that a highly cur­tailed insect pop­u­la­tion will likely affect repro­duc­tion, parental behav­ior and nestling sur­vival in addi­tion to direct con­t­a­m­i­na­tion by seed con­sump­tion and trophic accu­mu­la­tion with sub­lethal effect.”

Chemicals indi­rectly hit birdlife by slash­ing avail­able prey,” Luoni said. But they also affect birds directly, pro­vok­ing acute intox­i­ca­tion or, more fre­quently, chronic intox­i­ca­tion. Those are caused by sev­eral dif­fer­ent mol­e­cules such as neon­i­coti­noids and oth­ers that are under inves­ti­ga­tion.”

According to Luoni, in a coun­try widely praised for its bio­di­ver­sity, such as Italy, bird num­bers in agri­cul­tural areas have dropped by 30 per­cent since 2000. If only plains are con­sid­ered, where most inten­sive farm­ing is done, the drop exceeds 50 per­cent.

Considering the four anthro­pogenic pres­sures, the new research found inten­sive agri­cul­ture has broader effects in the west­ern regions of Europe, where it has been expand­ing faster. Of the 50 bird species affected by inten­sive farm­ing, 31 were neg­a­tively affected.

See Also:Organic Farms Produce Less, but Are More Cost Effective, Study Finds

We find a mostly neg­a­tive influ­ence of high-input farm cover not only for farm­land species but also for species with a diet at least partly based on inver­te­brates dur­ing the breed­ing sea­son, long-dis­tance migrants, and wood­land birds, i.e., a vast major­ity of the com­mon birds,” the researchers wrote.

The research also hinted at how large agri­cul­tural oper­a­tions use inten­sive farm­ing prac­tices more than smaller ones. Data show that birdlife fares bet­ter in coun­tries where small farms are the norm.


The study showed how bird species reacted evenly to the pres­sure fac­tors. For instance, ris­ing tem­per­a­tures neg­a­tively impacted 27 species, while 28 seemed to ben­e­fit from those changes.

Scientists also found that expand­ing for­est cover affected nine species and ben­e­fited 16.

Forest cover often expands in areas where agri­cul­ture is not prof­itable any­more, areas that end up being mostly aban­doned,” Luoni said. While this might ben­e­fit some wood­land species, it also reduces those open mead­ows cru­cial for other species.”

While some species may profit from changes trig­gered by human activ­i­ties, the over­all num­ber of birds fol­lows a trend of sharp decline.

Whereas the farm­land bird pop­u­la­tion dropped by almost 60 per­cent, other bird pop­u­la­tions were hit by a slower decline. Woodland bird num­bers dropped by 18 per­cent, urban dwellers by 28 per­cent, cold dwellers by 40 per­cent and hot dwellers by 17 per­cent.

To counter these trends, it is cru­cial to estab­lish and fol­low good agri­cul­tural prac­tices,” Luoni said. That means an approach to agri­cul­ture which must be based on agroe­col­ogy, where sus­tain­able farm­ing works with nature.”

According to Luoni, the increase in organic farm­ing in some areas pro­vides hope for the future.

However, the authors of the new research warned that fur­ther stud­ies are needed to fully under­stand the deep casual rela­tion­ships among the dif­fer­ent anthro­pogenic pres­sures and bird num­bers decline.

They also under­lined how cru­cial data are often under-reported by local and national insti­tu­tions. Still, they noted how their study pro­vides evi­dence of the agri­cul­tural prac­tices’ impact on a con­ti­nen­tal scale.

Considering both the over­whelm­ing neg­a­tive impact of agri­cul­tural inten­si­fi­ca­tion and the homog­e­niza­tion intro­duced by tem­per­a­ture and land-use changes, our results sug­gest that the fate of com­mon European bird pop­u­la­tions depends on the rapid imple­men­ta­tion of trans­for­ma­tive change in European soci­eties, and espe­cially in agri­cul­tural reform,” the researchers con­cluded.

Share this article


Related Articles