It took eight years, 200 commercial flights and 58 boat trips before ornithologist Edwin Scholes and photographer Tim Laman could say they’d made history. The pair are the first to document all 39 species of birds of paradise, famed for their outlandish coloring and bizarre mating dances. (The birds are prime examples of sexual selection, a type of natural selection that favors flashiness.) Scholes and Laman’s work is the basis of the National Geographic Museum’s “Amazing Avian Evolution” exhibit.

Why is it so difficult to document birds of paradise?
They’re only found in New Guinea and the northernmost parts of eastern Australia. These areas don’t have roads and are usually pretty mountainous and rugged.

What was the hardest part?
Getting to those display sites [where male birds are trying to impress females]. Some only display in the top of the forest canopy. Others display on a particular vine, so it’s like looking for a needle in a haystack. [There’s] tree climbing and putting up with days and sometimes weeks of trying to get the right activity from these birds.

What’s left to learn about the birds?
There are a lot of instances where we’ve just scratched the surface. The King of Saxony has huge, almost antennalike feathers that come out of the top of its head. How do they move those feathers? We don’t even know. They make sounds not only with their voice but also with their body parts, but we don’t know how.

National Geographic Museum, 1145 17th St. NW; $8, through May 12; 202-857-7700. (Farragut North)