Birds are among the best-studied animal groups, but their prehistoric diversity is poorly known due to low fossilization potential. Hence, while many human-driven bird extinctions — extinctions caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as land use change, fire, and the introduction of invasive species — have been recorded, the true number is likely much larger. By combining recorded extinctions with model estimates based on the completeness of the fossil record, scientists from the UK Centre for Ecology & Hydrology and elsewhere suggest that at least 1,300-1,500 bird species (around 12% of the total) have gone extinct since the Late Pleistocene epoch, with 55% of these extinctions undiscovered.
There are many potential causes of bird extinction connected to human activity today, including habitat loss, over exploitation, and the introduction of invasive species.
Previous analyses of bird extinction rates have focused on well-documented observed extinctions, beginning just over 500 years ago.
However, this approach may underestimate the magnitude of biodiversity loss associated with human activity, as some species of birds may have gone extinct before they were first formally recorded.
To estimate undiscovered extinctions, Dr. Rob Cooke from the UK Centre for Ecology & Hydrology and his colleagues first modeled fossil bird extinctions across 69 archipelagos (1,488 islands) as explained by multiple environmental predictors and the completeness of the fossil record.
They combined these estimates of undiscovered extinctions (archipelagos only) with estimates of fossil and observed extinctions across the globe.
Subsequently, they estimated the extinction date for all bird species lost since the Late Pleistocene and inferred extinction rates of birds through time
“Our study demonstrates there has been a far higher human impact on avian diversity than previously recognized,” Dr. Cooke…
Read the full article here