Caribbean was barn owl diversity hub before species spread globally

Barn owls live on every continent except Antarctica, but genetic evidence now shows that the Caribbean was their true birthplace in the Western Hemisphere. Less than two million years ago, these owls made an improbable journey across the Atlantic Ocean from Eurasia, arriving first in the islands of the Caribbean rather than on the mainland continents where they are most abundant today. From there, they dispersed to the Galápagos Islands and eventually to North and South America—a sequence that contradicts decades of scientific assumption about how these birds colonized the New World.

The discovery emerged from a study led by Min Zhao at the Florida Museum of Natural History, who sequenced DNA from dozens of owl specimens collected over the past 150 years and housed in museums across the country. By combining genetic data with radiocarbon dates from fossils, Zhao and his colleagues determined that the American barn owl, Tyto furcata, originated in the Caribbean and that the most genetically divergent barn owl lineages alive today are found there, not on the continents. This finding inverted the prevailing theory: scientists had long assumed barn owls arrived in the Americas via the Bering Land Bridge or by hopping across remnants of an ancient North Atlantic land bridge, then later colonized outlying islands. The new evidence suggests the opposite happened.

What makes this dispersal pattern plausible is the fossil record of giant barn owls that once thrived in the Caribbean. Jessica Oswald, a postdoctoral associate at the Florida Museum, discovered fossils of Tyto pollens in Cuba and the Bahamas—a species that stood about a meter tall, roughly twice the size of modern barn owls. A closely related species, the Hispaniolan giant barn owl (Tyto ostologa), inhabited nearby islands. Both species likely went extinct within the last million years, possibly as recently as the late Holocene after humans arrived in the region. The giant owls hunted large prey: hutias (rodents native to the Caribbean), monkeys, and possibly even young ground sloths. As humans colonized the islands and their hunting practices eliminated these prey species, the owls lost their food source and disappeared.

The giant barn owls may have inspired the chickcharney, a cryptid from Bahamian folklore described as an elfin, owl-like creature that brings good fortune to those who treat it kindly but misfortune to those who disrespect it. Local stories tell of the chickcharney spiriting away people who encounter it. Oswald heard these tales during fieldwork in the Bahamas in 2017 and 2019, and the fossils she and her colleagues recovered suggest the legend may have roots in actual encounters between humans and these enormous birds.

The trans-oceanic crossing from Eurasia to the Caribbean seems unlikely at first glance, but it is not without precedent in nature. Sea lavenders, plants in the genus Limonium, originated in the Mediterranean and dispersed across ocean distances to island archipelagos and eventually to the Caribbean. More tellingly, barn owls have a documented capacity for long-distance travel. In 1722, naturalist Mark Catesby recorded in his journal that during his voyage from England to North America, an owl appeared hovering over his ship at latitude 26 degrees North, roughly midway between Africa and America—a distance he estimated at no less than 600 leagues. The owl rested briefly on the vessel before disappearing into the sky. David Steadman, curator emeritus of ornithology at the Florida Museum and a co-author of the study, was not surprised by the barn owls' Atlantic crossing. Growing up on a farm in Pennsylvania, he had observed barn owls returning year after year to roost on his family's silo, always departing before winter snow obscured the meadow voles they hunted and returning once the snow melted. Barn owls are tropical and temperate birds; they cannot survive at high latitudes where snow persists. This biological constraint made the Bering Land Bridge route implausible from the start. "Owls are good dispersers, and barn owls are probably the best," Steadman said.

The Caribbean remains the most biodiverse region for barn owls in the Western Hemisphere, though that diversity is now a shadow of what once existed. At least nine barn owl species that inhabited the Caribbean are now extinct. Modern American barn owls have begun to fill some of the ecological niches left behind. In Hispaniola, American barn owls first appeared in the mid-1900s and have adapted to hunting smaller prey, including invasive rats that arrived with human ships. A similar pattern is unfolding in the Galápagos, where the lineage that arrived from the Caribbean more than a million years ago coexists with a more recent arrival from South America.

The study's findings carry implications for conservation. Until recently, scientists classified all barn owls as a single cosmopolitan species. Genetic research has since revealed multiple distinct species, and the American barn owl was formally designated as its own species only in 2024. The Galápagos barn owl, currently classified as a subspecies of the American barn owl, likely warrants elevation to full species status based on this research. The same may be true of a little-known subspecies in the Lesser Antilles that has received minimal scientific attention precisely because it was not considered endemic. Steadman noted that once species are recognized as genetically distinct and unique, they tend to attract more research and conservation focus. "There are very few records of it because it's not considered endemic, and there's minimal scientific interest in it," he said. "Now that we know these things are genetically distinct, there are some great projects out there waiting for people who want to study them."