08/12/2021 1:41 PM
Clarín.com
Dresses
Updated 08/12/2021 1:41 PM
Over the past
20,000-50,000 years
, birds have suffered a major extinction event, inflicted primarily by humans, with the
disappearance of around 10 to 20 percent of species.
The vast majority of extinct varieties shared several characteristics: They
were large, lived on islands and many of them did not fly,
according to a new study from Tel Aviv University and the Weizmann Institute.
A gray heron flies to try to catch a fish (EFE).
The leading cause of species extinction by humans today has shifted from hunting to the
destruction of natural habitats
for animals, but the researchers hope their findings will serve as warning signs regarding species of animals. birds currently in danger of extinction.
The study was led by Professor Shai Meiri from the George S. Wise School of Life Sciences School of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University, and Amir Fromm from the Weizmann Institute of Sciences.
The article was published in the Journal of Biogeography.
A black-tailed kite hummingbird (left) and a white-breasted buzzard feed (EFE).
"We 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 around the world. Those that became extinct in the last 300 years are relatively well known, while that the above species are known to science from remains found in archaeological and paleontological sites around the world. In total, we were able to list
469 species of birds that became extinct
in the last 50,000 years, but we believe that the actual number is a lot major, "explains Professor Meiri in a statement.
Researchers believe that the great extinction was caused primarily by humans
hunting birds for food or by animals brought to the islands by humans
, which fed on the birds and / or their eggs.
A rehabilitated female condor getting ready to fly in La Paz (Bolivia) (EFE).
This assumption is based on the fact that most of the bird remains were found in human sites, apparently belonging to birds consumed by the inhabitants, and in most cases the extinctions occurred shortly after the arrival of humans. .
What were the missing birds?
Most of the extinct species shared three main characteristics:
1.- Approximately 90 percent of them
lived on islands
: when humans arrived on the island, the birds were hunted by them or were victims of other animals introduced by humans, such as pigs, rats, monkeys and cats.
A hawk in the Palo Verde cloud forest, a nature reserve located in central Costa Rica (EFE).
2.- Most of the extinct bird species
were large, some very large
.
The body mass of the extinct species was found to be up to 10 times that of the surviving species.
Larger birds provided humans with a great deal of food, making them a
preferred target for hunters
.
Previous studies have found a similar phenomenon among mammals and reptiles, especially lizards and turtles that lived on islands: the largest were hunted by humans and became extinct.
Engraving of the hunt for one of the last moas (FLICKR).
3.- A large part of the extinct bird species
did not fly
and, often, could not escape from their pursuers.
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 have gone 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.
A flycatcher in the Palo Verde cloud forest, in Costa Rica (EFE).
Professor Meiri said: "Our study indicates that before the greatest extinction event of the last millennia, many more large birds, including giant and flightless birds, lived on our planet, and the diversity of birds living on the islands was much greater than at present. We hope that our findings serve as red flags for bird species currently threatened with extinction, so it is important to check if they have similar characteristics. However, it should be noted that conditions have changed considerably, and today the cause Mainly because the extinction of species by humans is not hunting, but the destruction of natural habitats. "
Europa Press.
GML