Orangutan

Extinction risks for natural populations of endangered species are likely being underestimated by as much as 100-fold because of a mathematical "misdiagnosis," according to a new study led by a University of Colorado at Boulder researcher.

Assistant Professor Brett Melbourne of CU-Boulder's ecology and evolutionary biology department said current mathematical models used to determine extinction threat, or "red-listed" status, of species worldwide overlook random differences between individuals in a given population. Such differences, which include variations in male-to-female sex ratios as well as size or behavioral variations between individuals that can influence their survival rates and reproductive success, have an unexpectedly large effect on extinction risk calculations, according to the study.

"When we apply our new mathematical model to species extinction rates, it shows that things are worse than we thought," said Melbourne. "By accounting for random differences between individuals, extinction rates for endangered species can be orders of magnitude higher than conservation biologists have believed."