Image credit: Wikimedia Commons
Declaring extinction is a move conservationists make with trepidation. Once a species has received the label, preservation efforts—and the money that supports them—end quickly. If a premature declaration is made, this can push a critically endangered species over the brink. If conservationists wait too long, however, they risk wasting precious time and money on a lost cause.
Now, a new model—being tested with the Dodo bird—is helping to simplify this decision with quantitative analysis.According to the IUCN Red List, an animal is labeled extinct "when there is no reasonable doubt that the last individual has died." Making this determination, however, is problematic. It requires extensive costly surveys to monitor species populations and search for lingering survivors. Even when a conclusion is finally made, history—and "Lazarus species" that have reemerged from extinction—shows that certainty is nearly impossible.
With funding and manpower limited—and the number of endangered species increasing at an alarming rate—there is a clear need for a precise model that would tell conservationists when the time has come to redirect their efforts.
Tracy Rout, a researcher at the University of Melbourne's School of Botany in Australia, believes her team has developed just such a model. She explained:
In terms of funding allocations, decisions are currently made in an arbitrary way, varying from agency to agency and species to species...our method would help make any implicit judgments of value more explicit.
Their model uses data about species sightings—both the number of surveys that have failed to find a species and the frequency of the most recent sightings—to calculate the probability the species is alive in the wild. It then compares this data to the cost of current and continued conservation efforts.
To test the model, Rout and her team have used data available for three species: The long-extinct dodo bird, the elusive ivory-billed woodpecker, and the threatened mountain pygmy possum.
The probability that a dodo bird exists in the wild is estimated to be 3.07 x 10-6, or, in other words, not very good. When placed into the model, this probability shows that efforts to conserve the species would be 17 million times more costly than beneficial.
In a more optimistic application of the model, the team looked at the mountain pygmy possum. It's chances of being alive in the wild are about .55 and the estimate value of the species to Australia is between $180 million and $410 million. This means, according to the researchers, that it would be valuable to conduct up to 66 more surveys before the species is declared extinct.
Rout commented that:
There's a big move towards more incorporation of decision-making theory and economics into conservation decision-making...it will at least make it more transparent why we're working on a particular species.
While such a system may seem a cold means of assessing the value of life, it could help conservationists make the difficult decisions about which species could most benefit from their limited time and resources.
Read more about species conservation:
Life on the Endangered Species Waiting List
Woodpecker Recovery Plan May be too Late
80 Rare Butterflies Released to Spend their Short Lives in the Wild
Extinct Frog Rediscovered in Australia