New method to quantify undetected extinctions

8 Mar 2016 NUS scientists invent new method and are planning to apply it to estimate undetected extinction in a wide range of animals and plants to assess impacts of deforestation and/or urbanisation on nature.

Humans often count the number of extinct species to assess their negative impact on nature, but many extinctions probably happen undetected, i.e., before science has even discovered the species. A team led by Profs Ryan CHISHOLM and Frank RHEINDT from the Department of Biological Sciences in NUS has developed a new method to estimate undetected extinction.

Profs Chisholm and Rheindt’s team used their new method to estimate undetected extinctions of Singaporean breeding birds. Of the 195 bird species known to have bred in Singapore during the last ~200 years, ~ about 30% are known to have gone extinct. However, their method suggests that the total extinction rate may have been closer to 33% if undetected extinctions are accounted for.

The new method is widely applicable and can be used to estimate total rates of extinction in any group of organisms at any geographic scale. There are no spatial or taxonomic boundaries to its application, meaning that it can be used for various exercises such as estimating extinction rates in dragonflies at Bukit Timah Reserve all the way to quantifying extinction across all the plants of the world.

Having an unbiased estimate of extinction rates is of paramount importance for gauging humanity’s impact on the planet in these times of human-induced ecological crisis.

 The scientists are planning to apply the new method to a wide range of animals and plants across various geographic scales, including Singapore, to assess the impacts of deforestation and/or urbanisation on nature.

ryan 2016

Figure shows the time series of detected resident bird species in Singapore (solid lines) and inferred undetected extinctions (dashed lines) with 95% CI (shaded region).



Chisholm RA, Giam X, Sadanandan KR, Fung T, Rheindt FE. “A robust non-parametric method for quantifying undetected extinctions.” Conservation Biology. DOI: 10.1111/cobi.12640