Human Activity Responsible for Extinction of 12% of All Bird Species, Study Finds

A study in Nature suggests that human activity has led to the extinction of nearly 12% of all bird species on the planet

Human Activity Responsible for Extinction of 12% of All Bird Species, Study Finds

In a scientific study recently published in Nature, an international team of researchers has shed light on the alarming magnitude of the global bird extinction crisis. The findings, obtained through sophisticated mathematical models, not only unveil the current state of bird extinctions, but also predict the potential scale of undiscovered losses.

According to Cooke et al's paper, "recorded extinctions with model estimates based on the completeness of the fossil record, we suggest that at least ~1300–1500 bird species (~12% of the total) have gone extinct since the Late Pleistocene, with 55% of these extinctions undiscovered (not yet discovered or left no trace). "

The research delves into a myriad of factors influencing bird extinctions, including the size of bird habitats, their proximity to other land masses, the timeline of human arrival, elevation, and temperature. By analyzing these variables, the researches identified human activity as directly linked to the disappearance of bird species.

"Moreover, we identify an intense human-driven extinction wave for birds (i.e., caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as deforestation, fire, and the introduction of invasive species), peaking ~1300 CE with a rate 80 (60–95) times the background extinction rate."

One of the study's major revelations is the likelihood of significantly more extinct bird species than previously recognized in certain areas. Using Aotearoa, New Zealand as a benchmark, the researchers extrapolated estimates for other regions, providing insight into the potential undiscovered extinctions awaiting revelation.

Human activities, particularly the arrival of humans in new territories, emerged as a significant driver of bird extinctions. Additionally, geographical factors such as elevation and temperature played crucial roles. The study serves as a stark warning, emphasizing the urgent need for global conservation efforts to protect bird species from further decline.

To ensure the accuracy of their predictions, the scientists established upper limits, representing the maximum number of birds a region could feasibly lose. Employing sophisticated techniques, the researchers aimed to avoid unrealistic projections, providing a more reliable basis for understanding the gravity of the situation.

The numerical data extracted from the study paints a vivid picture of the extinction landscape. The researchers identified key predictors, including research effort, human arrival, isolation distance, elevation, temperature, and native rodents. The Linear Model (LM) employed in the study exhibited a remarkable predictive performance, explaining a substantial proportion of the variance in fossil bird extinctions.

Extrapolating from the LM model, the researchers estimated the potential number of undiscovered extinct birds for each archipelago. The findings underscore the critical importance of conservation efforts in mitigating the ongoing bird extinction crisis.

This study serves as a wake-up call, urging global collaboration to protect avian biodiversity. As human activities continue to reshape the planet, proactive measures are essential to safeguard the diverse and irreplaceable bird species that enrich our ecosystems.