DICE research shows that extinction is difficult to prove for Earth’s ultra-rare species

A recent study from the Durrell Institute of Conservation and Ecology (DICE) has called for an increase in scientific surveys and collection of specimens to confirm the extinction of ultra-rare species.

Dr David Roberts, Reader in Biodiversity Conservation, concluded from the research that there are currently insufficient scientific surveys to determine whether many of the Earth’s rarest species, those known only from a single specimen, still exist.

As a case study, Dr Roberts investigated the orchids of Madagascar utilising three different methods of scientific survey effort. Results showed that, as of 2000, up to nine of the 236 orchid species known from a single specimen could be extinct. Furthermore, up to two additional species could be considered as extinct by 2018 – assuming no new scientific collections have been made. However, whether the remaining 225 orchid species still exist is unknown as there have been insufficient scientific surveys to determine their fate.

As extinction is final, we need to have as much information as possible. This can come from digitising and making already existing data (that is currently locked away in museum cupboards) widely available. Furthermore, it can come from collecting new knowledge through scientific surveys and making this data widely available as quickly as possible, as well as collecting other information such as the current state of habitats which can be a useful indicator as to whether species still possibly exist.

Dr Roberts said, “Most species are poorly known because of the very fact they are rare, which brings challenges for conservation practitioners. With conclusions of extinction being made on available data, it is difficult to know if an ultra-rare species is extinct or may have just gone unnoticed. The conservation community needs to work in collaboration to adapt to developing species’ data resources to deliver more accurate assessments of some of the world’s rarest species.”

Inferring the extinction of species known only from a single specimen by David L. Roberts and Ivan Jarić is published in Oryx—The International Journal of Conservation (https://doi.org/10.1017/S0030605319000590)