Methods
This organization’s "Red List" was the primary data source used by the researchers to track species population trends.
What is the IUCN?
This specific class of vertebrates showed the most alarming trend in Figure 4, with nearly 55% of its decreasing species still being classified as "Low Concern."
What are birds?
To map global biodiversity, the researchers divided the Earth's land surface into 22,000 of these geographic units, each measuring 10,000 km^2
What are quadrats?
In a detailed analysis of 177 mammalian species, the researchers found that every single one of them had lost at least this percentage of its historical geographic range.
What is 30%?
While the media often focuses on "extinction," this paper argues we should focus on the loss of these local groups, which provides a more accurate measure of the planet's health.
What are populations? (or demographic units)
The authors use this term to describe the current mass loss of species because it is caused specifically by human activity.
What is anthropogenic extinction?