When conservationists removed 131 feral cats from Japan’s remote Ogasawara Islands, no one imagined it would spark an ecological miracle. Within three short years, the population of a nearly extinct bird — the red-headed pigeon — increased tenfold. Against all odds, these rare birds have managed to rewrite the rules of genetics and survival.
A miraculous comeback for an endangered species
Published in Communications Biology, this groundbreaking study reveals one of the fastest recoveries ever recorded in modern conservation. After the removal of their top predator, the red-headed pigeon — a critically endangered, endemic species found only in the Ogasawara Islands — demonstrated extraordinary genetic resilience. The research, led by Kyoto University, is reshaping how scientists think about endangered populations and genetic survival.
The red-headed pigeon (Columba janthina nitens) stands about 16 inches tall, with a distinctive copper-colored head and gray-brown plumage. Once common in the island forests, the species nearly vanished in the late 20th century as deforestation and feral cats pushed it to the brink. By 2008, fewer than 80 individuals remained.
The Ogasawara archipelago, a UNESCO World Heritage site, hosts a fragile ecosystem that evolved in isolation for millennia. But the introduction of invasive species — particularly cats — severely disrupted this delicate balance.
In 2008, fewer than 80 red-headed pigeons remained on the Ogasawara Islands, but the removal of the main predators of this rare bird species helped save it. © tororo, iStock
Trapping cats to save birds
In 2010, conservationists launched an emergency cat-trapping campaign on Chichijima Island. Between 2010 and 2013, they captured 131 feral cats, cutting their population to fewer than 20. With predators removed, the pigeons rebounded dramatically.
The numbers tell the story: the adult population rose from 111 to 966, while juveniles jumped from 9 to 189. This explosive growth remains one of the most successful avian recoveries ever documented.
The genetic secret behind their survival
Normally, such small populations suffer from inbreeding and harmful genetic mutations — a biological trap that makes recovery nearly impossible. Yet somehow, the red-headed pigeon avoided this fate.
A research team led by Daichi Tsujimoto sequenced the genomes of both wild and captive pigeons. To their surprise, the birds carried fewer harmful mutations than expected — even fewer than some larger, healthier species.
The secret lies in a process called genetic purging, which took place over centuries. Because the pigeon population was small and isolated for so long, natural selection gradually eliminated the most damaging mutations. Over time, this “genetic cleansing” left behind a stronger, more resilient lineage.
Several factors contributed to this surprising adaptability:
- Long-term geographic isolation and natural selection.
- A small but historically stable population.
- Gradual elimination of harmful alleles.
- Retention of enough genetic diversity to ensure survival.
Lessons for conservation’s future
While the species’ rebound is inspiring, its future remains uncertain. Its population is still well below historical levels, and its limited gene pool may hinder adaptation to new environmental changes.
Still, the discovery challenges conventional wisdom. It shows that, in rare cases, small populations can evolve mechanisms that help them survive even the most severe genetic bottlenecks.
The findings suggest that detailed genetic studies could help conservationists identify other species with hidden resilience — and tailor protection strategies accordingly.
The story of the red-headed pigeon proves that even on the edge of extinction, life can find a way back — especially when science, timing, and nature align perfectly.
