The equatorial Pacific Ocean islands boast a number of unique plant and animal species from tortoises to iguanas to penguins, but frigatebirds can fly hundreds of miles across open ocean, suggesting their gene flow should be widespread and their genetic makeup should be identical to those of the frigatebirds on the mainland coast of the Americas, researchers from the Smithsonian Conservation Biology Institute say.
But three different genetics tests all yielded the same result -- the Galapagos seabirds have been genetically different from the frigatebirds elsewhere for more than half a million years.
"This was such a surprise," Frank Hailer, a research associate at institute, said. "It's a great testimony to just how unique the fauna and flora of the Galapagos are. Even something that is so well-adapted to flying over open oceans is isolated there."
What is clear is that this small population of genetically unique frigatebirds is a vulnerable group.
Any catastrophic event or threats by humans could wipe out the approximately 2,000 frigatebirds that nest on the Galapagos Islands, researchers say.
"The magnificent frigatebirds on the Galapagos are a unique evolutionarily significant unit, and if the Galapagos population did go extinct, the area will not likely be recolonized rapidly by mainland birds," Robert Fleischer, head of the institute's Center for Conservation and Evolutionary Genetics, said. "This emphasizes the importance of protecting this small population of birds there."