After four decades of work, researchers published the origin of Big Bird (not that one) in Science this week—and it's scientifically unprecedented. The BBC reports that for the first time ever, researchers were able to watch the rise of a new species play out in nature. "It's an extreme case of something we're coming to realize," a speciation expert says. "Evolution in general can happen very quickly." According to a press release, in 1981 an interloper arrived on Daphne Major, a tiny island in the Galapagos archipelago where Peter and B. Rosemary Grant were studying Darwin's finches. The new bird, bigger than the three species living on the island, was a large cactus finch that had apparently flown from an island more than 60 miles away. Unable to return, it mated with a local medium ground finch.
The resulting offspring, nicknamed the Big Bird lineage for their size, were unable to attract partners from the local finch population due to their weird song and unusual beak size and mated only among themselves. B. Rosemary Grant calls it a "terrifically inbred lineage," Science Alert reports. Within just two generations, the Big Birds were a distinct species, as confirmed by genomic sequencing and their own unique physical characteristics. An expert says if a naturalist came to the island today, they would simply believe there were four native finch species with nothing giving away the Big Bird as a recent addition. It was touch-and-go there for a minute—droughts in 2002 and 2003 killed all but two Big Birds—but there are now 30 or so members of the hybrid species living on Daphne Major. (The savior of the Galapagos tortoise is a dirty, dirty old man.)