This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Species reduced to fewer than 50 individuals in the wild are not automatically doomed to extinction, according to a major study co-authored by researchers at the Zoological Society of London and Monash University. The findings, published in Proceedings of the Royal Society B, challenge longstanding ecological theories that severely bottlenecked animal populations inevitably collapse due to inbreeding and loss of genetic diversity.
By reviewing every bird and mammal species known to have fallen below 50 wild individuals since 1950, researchers found that active, targeted conservation can successfully turn the tide for species on the very edge of survival. Donal Smith, from the Monash University School of Biological Sciences, said the findings offer an empirically grounded note of hope for global biodiversity. "For decades, conservation decisions have been influenced by the idea that once a population drops below a certain threshold, recovery is severely inhibited by smallness itself due to genetic or demographic factors," Smith said.
"Our work shows that population size alone shouldn't determine whether we give up on a species. When we actively tackle the external pressures driving their decline and directly support their numbers, small populations show a striking capability to recover." The study evaluated 141 bird and mammal species with sufficiently documented histories. Of the 51 species that received direct conservation action, such as invasive predator control, habitat restoration, captive breeding or translocations, 61% recovered to at least 100 individuals.
In contrast, 37% of species that received no direct support went extinct, and only 2% recovered to at least 100 individuals. Combining threat mitigation with direct population management yielded the highest rates of success, driving recoveries in iconic species such as Australia's Lord Howe woodhen, which rebounded from just 23 birds in the late 1970s to more than 1,600 today. Co-author Rohan Clarke, also from the Monash School of Biological Sciences, said the research presents a strong case against writing off species through hard-line conservation triage tactics.
"Abandoning critically endangered species because their numbers look too low is a mistake," Clarke said. "While genetic risks are real, our history shows that human intervention works. Investing in active, science-backed management isn't futile; rather, it's the very thing that saves a species from disappearing forever." Donal Smith et al., Inevitable fates?
The recovery potential of small populations, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2026.2436 Swati Mestri holds a bachelor's degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space.
Extract — continue reading at the source.
