The red-headed wood pigeon, a unique bird found only on Japan’s Ogasawara Islands, has made a stunning comeback from near extinction. In the early 2000s, fewer than 80 of these pigeons remained. After conservationists removed feral cats, a major threat, the population began to surge. Within just three years, the number of red-headed wood pigeons rose significantly, drawing the interest of researchers at Kyoto University.
Daichi Tsujimoto, the lead author of a recent study published in Communications Biology, reflected on this surprising recovery. Typically, small populations face the risk of inbreeding, leading to harmful genetic changes that hinder survival. However, the red-headed wood pigeon defied these odds.
Its journey is quite remarkable. Once abundant, the population shrank due to habitat destruction and predation from feral cats. By 2008, they were on the brink of extinction. Conservation efforts, especially the removal of feral cats starting in 2010, made a significant difference. Over three years, these efforts led to trapping 131 feral cats, which reduced their numbers drastically. Meanwhile, sightings of red-headed wood pigeons jumped from 111 to 966 adults.
This bird is about 40 cm long, with a striking reddish head and grey-brown body. It’s different from the more common Japanese wood pigeon, which is found on the mainland and nearby islands. The study of this pigeon offers insights into how some species may adapt and survive even after a drastic population decline.
Researchers sequenced the genomes of both the red-headed wood pigeon and the Japanese wood pigeon. What they found was surprising: the red-headed wood pigeon had fewer harmful mutations than its more common relative. It appears that years of living as a small, isolated population allowed it to shed detrimental genetic changes, a process known as genetic purging. This gave the pigeons resilience, enabling them to survive population bottlenecks.
Yuji Isagi, a team leader, noted that this unique genetic history gave the red-headed wood pigeon a survival advantage not seen in many other endangered species. This challenges the common notion that inbreeding always leads to problems. Instead, it shows that small populations can evolve positively over time.
While the recovery is promising, challenges remain. The pigeon’s current numbers still fall short of historical levels, and a smaller gene pool could make future adaptation difficult. Therefore, continuing efforts to restore their population is crucial.
This case highlights the importance of conservation efforts and understanding how isolation can shape genetic resilience. If you’re interested in the detailed study, you can explore more about the findings in this link.
