Dark Extinction: Over 1,400 of World's Bird Species Driven to Extinction by Human Activities

Humans have wiped out thousands of bird species, with serious implications for the ongoing biodiversity catastrophe, according to a new study. Human activity has led to the loss of almost 12% of the world's bird species, twice as many as previously thought.

1,430 Bird Species Extinct

The study, which was published in Nature Communications, estimates that approximately 1,430 bird species have become extinct since the Late Pleistocene period, which began approximately 120,000 years ago.

Known bird extinctions, as determined by fossil or other data, account for approximately 640 species. The new estimate includes birds that went extinct without being recorded, which scientists refer to as a "dark extinction."

Using fossil or other data, known bird extinctions account for approximately 640 species. The birds that went extinct without anyone recording the occurrence are included in the updated estimate; this is known to biologists as a "dark extinction."

The researchers used a statistical model to extrapolate from the 640 bird species that are known to be extinct in order to determine the number of undiscovered extinctions.

Since there had been no recorded extinctions of bird species in New Zealand, the model utilized that nation as the baseline for the loss of bird species.

The team estimated the number of species that could have existed on an island using the data from New Zealand. The number of known extinctions and the number of surviving birds were then removed. The number of undiscovered extinctions is the result.

The study concentrated on island bird populations due to the difficulty of non-migratory birds spreading.

"Islands are the best place to study extinctions: 90% of extinctions are on islands, because island birds have nowhere else to go," said Dr. Rob Cooke, an ecological modeller at the UK Centre for Ecology and Hydrology and the paper's lead author.

Serious Implication To Environment

The main causes of the extinction of bird species include fires, overhunting, deforestation, and invasive species.

The study revealed that the major extinction events took place in the 14th century, when the largest known human-driven vertebrate extinction wave caused species loss in the eastern Pacific at a rate that was about 100 times faster than natural extinction.

Human settlement caused deforestation and the introduction of invasive species, which in turn caused extinctions.

Excessive bird extinction rates represent a loss to our knowledge of the ecological diversity, evolutionary history, and species richness of birds.

The significant responsibilities that these birds would have performed in a larger environment are also absent.

Because of their ability to disperse seeds, pollinate plants, clean up dead bodies, and fertilize coral reefs and the surrounding land with their droppings, birds are essential to Earth's ecosystems.

"This will have had cascading harmful effects on ecosystems so, in addition to bird extinctions, we will have lost a lot of plants and animals that depended on these species for survival," said Dr. Spren Faurby of the University of Gothenburg, a co-author of the study.