A study of every bird and mammal species known to have dropped below 50 wild individuals since 1950 found that targeted conservation works, Monash University and the Zoological Society of London said in a Nov. 4 release. The endangered species recovery study appears in Proceedings of the Royal Society B. Of the 51 species that received direct conservation action, 61% recovered to at least 100 individuals. The authors use the result to argue against writing off species because their numbers look too low.
What the Study of 141 Species Found
The researchers found 141 species with enough history to analyze. The 51 that received direct action got predator control, habitat restoration, captive breeding or translocation. The 61% recovery rate means about 31 of those species reached 100 individuals, a calculation from the two figures. Species with no direct support did far worse. Among them, 37% went extinct and 2% reached at least 100 individuals. If the no-support group is the other 90 species, that is about 33 extinctions and about two recoveries, a calculation from the release’s figures.
The Lord Howe Woodhen Example
The release points to the Lord Howe woodhen, which grew from 23 birds in the late 1970s to more than 1,600 today. That is roughly 70 times its starting number, a calculation from the two figures. The study found that combining threat mitigation with direct population management produced the highest success rates.
Why the Authors Reject Triage by Headcount
Conservation groups with limited money sometimes use triage frameworks that deprioritize species once their numbers fall below a threshold. The authors say the data do not support that practice. “Abandoning critically endangered species because their numbers look too low is a mistake,” said Rohan Clarke, a professor in Monash University’s School of Biological Sciences and a co-author, in the release.
The fair limit on the result is scope. The 61% applies to the 51 species that received help and not to all 141, and the study covers birds and mammals only. The woodhen is one illustrative case, not the average one. The paper is titled “Inevitable fates? The recovery potential of small populations,” and it is published now in Proceedings of the Royal Society B.
