Madrid, 12 (European Press)
Over the past 20,000 to 50,000 years, birds have experienced major extinctions, primarily caused by humans, with approximately 10 to 20 percent of species disappearing.
The vast majority of extinct taxa shared many characteristics: they were large, lived on islands, and many did not fly. According to a new study from Tel Aviv University and the Weizmann Institute.
The main cause of species extinction by humans today has shifted from hunting to the destruction of animals’ natural habitats, but the researchers hope their findings will serve as warning signs regarding animal species, and birds that are currently in danger of extinction.
The study was led by Professor Shai Meri of the George S. Wise School of Life Sciences in Zoology and the Steinhardt Museum of Natural History at Tel Aviv University, and Amir Fromm of the Weizmann Institute of Science. The article was published in the journal Biogeography.
“We have conducted a comprehensive review of the scientific literature and, for the first time, collected quantitative data on the number and characteristics of extinct bird species worldwide. Those that have become extinct in the past 300 years are relatively known, while the above species are known to science from remains found in archaeological sites and excavations In total, we have been able to list 469 species of birds that have become extinct in the last 50,000 years, but we believe the actual number is too high, Professor Merry explains in a statement.
Researchers believe that the Great Extinction was caused primarily by humans hunting birds for food or animals brought to the islands by humans, feeding on birds and/or their eggs. This assumption is based on the fact that most bird remains have been found at human sites, apparently belonging to birds that were consumed by the population, and in most cases the extinctions occurred shortly after the arrival of humans.
Most of the extinct species share three main characteristics:
1.- Almost 90 percent of them lived on the islands: When humans arrived on the island, birds were either hunted by them or were victims of other animals introduced by man, such as pigs, rats, monkeys, and cats.
2.- Most of the extinct bird species were large and some are very large. The body mass of extinct species has been found to be up to 10 times that of the remaining species. Large birds provided humans with a great deal of food, making them a favorite target for hunters. Previous studies found a similar phenomenon among mammals and reptiles, especially lizards and turtles that lived on the islands: the largest of them were hunted by humans and became extinct.
3.- A significant part of extinct bird species did not fly and, often, was unable to escape from their pursuit. The study found that the number of flightless bird species that became extinct is twice the number of flightless species that still exist today. In all, 68 percent of the flightless bird species known to science became extinct. One of the best known examples is the moa bird in New Zealand: 11 species of moa became extinct in 300 years, due to hunting by humans.
Professor Merry said: “Our study indicates that before the largest extinction event in the last millennia, many large birds, including flightless giants, lived on our planet, and the diversity of birds living on the islands was much greater than we hope now. Our findings serve as red flags for bird species that are currently threatened with extinction, so it is important to check whether they have similar characteristics.However, it should be noted that conditions have changed considerably, primarily due to the extinction of species from Before humans is not hunting, but the destruction of natural habitats. ”