When a species dies out and only a few individuals remain, the whole world watches with alarm as the death of the last representative. Such was the case with Sudan, the last male northern white rhino to die last summer.
However, a study published in the journal “” showed that as many as eight rare bird species may have already become extinct without the whole world noticing.
An eight-year study funded by the non-profit organization analyzed 51 endangered bird species and found that eight of them could be classified as extinct or very close to extinction: three species were found to be extinct, one extinct in the wild nature and four are on the verge of extinction.
One species, the blue macaw, was featured in the 2011 animated film Rio, which tells the story of the adventures of a female and male blue macaw, the last of the species. However, according to the findings of the study, the film was a decade too late. In the wild, it is estimated that the last blue macaw died in 2000, and about 70 individuals still live in captivity.
The International Union for Conservation of Nature (IUCN) is a global database that tracks animal populations, and Birdlife International, which frequently provides IUCN estimates, reports that three bird species appear to be officially classified as extinct: the Brazilian species Cryptic treehunter, whose representatives were last seen in 2007; the Brazilian Alagoas foliage-gleaner, last seen in 2011; and the Black-faced Hawaiian Flower Girl, last seen in 2004.
The authors of the study estimate that a total of 187 species have gone extinct since they began keeping records. Historically, island-dwelling species have been the most vulnerable. About half of species extinctions have been observed to be caused by invasive species that have been able to spread more aggressively across the islands. It was also found that almost 30% of the disappearances were caused by hunting and trapping exotic animals.
But conservationists are concerned that the next factor will be deforestation due to unsustainable deforestation and agriculture.
“Our observations confirm that a tide of extinctions is on the rise across the continents, driven largely by habitat loss or degradation due to unsustainable agriculture and logging,” said Stuart Butchart, lead author and chief scientist at BirdLife.
In the Amazon, once rich in bird species, deforestation is a growing concern. World Wildlife Fund, between 2001 and 2012, more than 17 million hectares of forest were lost. An article published in March 2017 in the journal “” states that the Amazon basin is reaching an ecological tipping point – if 40% of the region’s territory is deforested, the ecosystem will undergo irreversible changes.
Louise Arnedo, a biologist and senior program officer at the National Geographic Society, explains that birds can be particularly vulnerable to extinction when they face habitat loss because they live in ecological niches, feeding only on certain prey and nesting in certain trees.
“Once the habitat disappears, they will also disappear,” she says.
She adds that fewer bird species can only exacerbate deforestation problems. Many birds serve as seed and pollinator dispersers and can help restore forested regions.
BirdLife says more research is needed to confirm the status of four more species, but none of them have been seen in the wild since 2001.