Earth is closer to a mass extinction event than previously believed as scientists warn that nearly half of the planet's animal species are experiencing significant population declines, which is almost twice the number estimated in earlier assessments.
The study, titled "More Losers Than Winners: Investigating Anthropocene Defaunation Through the Diversity of Population Trends" published in Biological Reviews, highlights that the global loss of wildlife is far more dire than previously understood. The ongoing decline of species populations is now deemed to be "significantly more alarming," raising concerns about the potential onset of a sixth mass extinction event.
Assessing Extinction Risks of Animals
Human activities have already caused the extinction of numerous species and pushed many others to the brink, leading some scientists to attribute the current crisis to human-driven factors. Evolutionary biologist Daniel Pincheira-Donoso expressed deep concern over the findings, describing them as "very alarming."
As per MailOnline's report, the research team examined over 700,000 species across various categories, such as mammals, birds, reptiles, amphibians, fish, and insects, to assess the vulnerability of populations to extinction.
The investigation revealed that 48% of the species analyzed are experiencing declines. Particularly surprising was the finding that 33% of species previously considered to be "non-threatened" are now facing significant population declines, indicating a more widespread and concerning situation than previously recognized.
The study led by Pincheira-Donoso and his team sought to provide a broader understanding of declining populations. They utilized data on population trends collected by the International Union for Conservation of Nature (IUCN) and its conservation partners, comparing it to traditional assessments of extinction risk.
The analysis revealed surprising declines in mammals, birds, and insects, while amphibians faced particularly severe risks due to their susceptibility to chemicals, diseases, and fungi. On the other hand, fish and reptiles seemed to have more stable population figures, indicating a relatively better situation.
However, the overall picture was concerning, as only a small percentage of species were found to be thriving amidst human population growth and climate change, with a mere 3% experiencing population increases. Pincheira-Donoso expressed alarm over this finding, emphasizing the need for attention and action.
The study highlights the urgency of addressing the declining populations of various species across different categories and the need for conservation efforts to mitigate the impacts of human activities and environmental changes.
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Tropical Animals At the Highest Risk of Extinction
The study also reveals that declines in species are more prominent in tropical regions, primarily due to the heightened sensitivity of tropical animals to rapid environmental temperature changes. Geographically, this concentration of declines raises concerns about the vulnerability of species in these areas.
Craig Hilton-Taylor, the head of the IUCN Red List, acknowledged the concerns expressed in the study but expressed reservations about the potential overestimation of the situation. He told CNN that using population data across various animal groups, including those with limited data availability, may be less robust compared to the IUCN's Red List criteria, which considers species trends over longer time frames.
However, Brendan Godley, a conservation science professor at the University of Exeter who was not involved in the study, praised the research for its comprehensive coverage of global vertebrate groups and insects. He highlighted the novel insights provided by the study's findings, indicating its significant impact on understanding population trends and raising awareness about the state of biodiversity.
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