Scientists have warned us that a sixth mass extinction might be inevitable, and about 30 percent of vertebrates will significantly decline in population numbers over the next two decades. However, they found out who might be the first species to be threatened. After a thorough analysis of all vertebrates, they discovered body size is an important indicator of the extinction risk.
Size is important when assessing an animal’s extinction risk
Researchers gathered data from 27,647 vertebrates, and assessed how at risk they were to go extinct. The results showed the extremes are the most endangered. Therefore, the largest vertebrates, together with the smallest ones, are at the highest risk. Among these threatened species, there are vertebrates living in all kinds of environments, and from all families.
William Ripple, one of the scientists involved in the study, says such a risk assessment is extremely helpful.
“Knowing how animal body size correlates with the likelihood of a species being threatened provides us with a tool to assess extinction risk for the many species we know very little about.”
Humans are the main factor which puts them in danger
Therefore, animals of a medium size are safe, but the larger and smaller ones are in a different situation. The larger ones, who weigh more than 2.2 pounds, are threatened by human action. They are in danger of harvesting, since humans often engage in activities like hunting, fishing, or anything that implies their entrapment. The smaller species are threatened by different factors. Those weighing less than 3 ounces have their habitat in danger, again, as an effect of human activity.
Among these threatened animals, there are the Komodo dragon, Somali ostrich, or Atlantic sturgeon, as large animals, and the hog-nosed bat, gray gecko, or Clarke’s banana frog, as small animals. Knowing which species are especially threatened is important, since we can take measures to protect them, and prevent a mass extinction.