Species' threat of extinction 'underestimated'
Thursday, 03 Jul 2008 13:00
Some gorilla species are endangered
The extinction risk of endangered species may be underestimated by as much as 100 times, according to new research.
Scientists at the University of Colorado say the problem is a result of a mathematical mistake.
Their study, published in the journal Nature, claims that current mathematical models used to determine the extinction threat of species worldwide overlook random differences between individuals in a given population.
It argues that such differences, which include variations in male-to-female sex ratios as well as size or behavioural variations between individuals that can influence their survival rates and reproductive success, have an unexpectedly large effect on extinction risk calculations.
Researcher Brett Melbourne said that when the team applied their new mathematical model to extinction rates, they found that "things are worse than we thought".
"By accounting for random differences between individuals, extinction rates for endangered species can be orders of magnitude higher than conservation biologists have believed," he added.
The researchers conclude their study by arguing that the extinction risk for many endangered species "need to be urgently re-evaluated with full consideration of all factors".
According to a 2007 report by the International Union for Conservation of Nature more than 16,000 species worldwide are threatened with extinction.