This seabird was thought extinct for over 300 years. It now has 165 established breeding pairs, according to Jeremy Madeiros, Bermuda’s chief terrestrial conservation officer, writing on the Nonsuch Expeditions site . In 2025, 78 chicks successfully fledged, the second-highest total on record, behind only the 79 chicks of 2021.
Some species get a second chance. The cahow is one of them.
Hunting was painful too. Dr. It identified storm damage and erosion as the biggest threat to the bird’s survival at the time. So the team turned to larger, nearby Nonsuch Island, which is higher and far more resistant to hurricane flooding and sea level rise. The cahow’s story shows what patient conservation can achieve.
The bird’s last nesting sites remained undiscovered for about 330 years. Then, in 1951, only 18 breeding pairs were rediscovered on four tiny half-acre rocky islets, Madeiros says. The study reports slightly different early figures: 13 to 14 pairs on three islets in 1951, and a 1961 survey that found two more breeding sites, raising the known total to 18 pairs. David Wingate managed the species for 40 years. He controlled the rats and built artificial burrows; when he retired in 2000, the population had risen to 53 pairs. Madeiros has managed the work for the past 25 years, he wrote in July 2025, and the population has since tripled to 165 established breeding pairs. The original islets are small and low-lying, under 10 meters (about 33 feet) high, and vulnerable to storm damage, the study says. Since that first egg in 2009, the Nonsuch colonies have grown to 40 breeding pairs. Madeiros says the island could eventually support up to 5,000 pairs, but he does not expect to live to see those numbers. He still considers the cahow endangered, and the 2012 study called it one of the rarest seabirds in the world. In a March 2026 update, he reported that eight chicks had hatched in one Nonsuch colony, with ten more eggs on the way: five hatching and five fertile eggs still developing.
The authors think the birds there probably declined due to overharvesting, and then disappeared when the land was cleared and overgrazed.
A 2012 study in Bird Conservation International by Nicholas Carlile, David Priddel and Jeremy Madeiros says Nonsuch Island was believed to be one of the “bird islands” where early settlers collected hundreds of birds each night for food.
