Researchers have found that bird species known as “white-eyes” develop faster than other species.
DNA analysis reveals that all 80 species of white eyes emerged in the last 2 million years.
A handful of other birds and mammals have been known to adapt to new environments in such short order, but white eyes are unique because their speciation isn’t a simple reaction to shifts in local habitats, said study author Christopher Filardi.
“White-eyes evolved into dozens of new species extremely fast while simultaneously spreading across much of [the southern] hemisphere,” he said. “At this geographic scale, there is no one thing from the outside that could have made this happen; there is something special about those birds.”
White eyes may evolve faster, in part, because females can start breeding as young as four months old. It takes most tropical songbirds closer to a year to reach sexual maturity, Filardi explained.
And unlike most birds, white eyes are hardwired to be social. They forage, travel, and even preen together, making it easier for them to colonize, according to the study.
Silvereye/Waxeye/Tauhou closeup by digitaltrails, Creative Commons on Flickr
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