A study found that many bird and mammal populations below 50 can still recover

Bird and mammal populations that fall below 50 animals in the wild are not automatically finished, a study co-authored at Monash University and the Zoological Society of London has found. Phys.org reported the paper on November 5, 2026. It is published in Proceedings of the Royal Society B. Lead author Donal Smith, of Monash, said conservation choices have long been shaped by the idea that once numbers drop under a threshold, smallness itself blocks recovery through genetics or chance. The review says population size alone should not decide whether people give up.

The authors looked at every bird and mammal species known to have fallen below 50 wild individuals since 1950, and kept the 141 with histories documented well enough to judge. Of the 51 that received direct help, such as predator control, habitat restoration, captive breeding, or moving animals, 61 percent later reached at least 100. Of the species that got no such direct support, 37 percent went extinct, and only 2 percent recovered to at least 100. Help that both eased the outside threat and managed the population did best. The paper points to the Lord Howe woodhen, which went from 23 birds in the late 1970s to more than 1,600. Co-author Rohan Clarke said genetic risks are real, and that the record is about intervention, not about doing nothing. The study covers species with a paper trail. It is not a promise for every animal that is rare today, and it does not say a population under 50 is safe.