"Each case had to be opened and it's a pretty amazing process. The whole things slides out and our staff were able to dust all the specimens and clean every eyeball. And there's over a thousand birds on display so around two thousand two hundred and fifty eyeballs had to be cleaned by hand," Tom Skwerski, project manager of exhibitions, said.
For hundreds and hundreds of years scientists have been studying birds. But in the last ten years they have learned more than perhaps all the previous years combined. And it's all because of DNA.
"DNA has revolutionized our understanding of the tree of life for birds," Shannon Hackett, associate curator of birds, said. "The tree of life. How birds how related to each other. Ah, we have traditional ideas and they've all been turned on their heads in the last ten years."
For instance, a small water bird called the grebe was thought to be related to the loon. But that's not the case.
"When we used DNA to figure out relationships it turns out that they're actually more closely related to flamingos," Hackett said. "I know they don't look anything like flamingos."
How about our beloved backyard robin, which, by the way, goes back over a hundred million years? Well, it is related to other song birds but it's also a cousin of the peregrine falcon.
"Falcons are related to robins and parrots -- not to hawks and owls, you might have seen them with traditionally," Hackett said.
So fly on by to bird hall exhibit. There's no extra charge once you're in the museum, http://fieldmuseum.org/ .