"I know for a fact that there is no other research institution or museum anywhere in the world who has someone like Bob on their staff," said Keith Thomson, a former president of the academy.
Many people aspire to master a plethora of subjects, but few succeed. Thomson thinks of Peck as "a throwback to another age of natural history, when you could be an artist, an explorer, in his case a photographer, a writer, a gardener."
In the academy library, "Bob is likely to appear with some visitor in tow, expounding earnestly on Abe Lincoln's hair" - part of the academy's collection of presidential locks - "or Charles Willson Peale's portraits," Thomson says.
If Peck's full mustache and beard make him look like some of the 19th century explorers he reveres, that's not quite the intent.
True, he regards the period as a golden age of natural history. Before that, voyagers like the British explorer James Cook were still getting the broad overview of the world. By the 19th century, "they were getting down and dirty into the details of flora and fauna," Peck says with delight.
Back to the beard. Peck grew it during a 1978 hiking trip through the Southeast to follow the trail of the Philadelphia naturalist William Bartram.
The reason he's kept it all these years, even as it changed from dark brown to mostly white, is that it saves him time.
Five minutes a morning over several years adds up to another article he can publish, another book he can write.
At 57, Robert McCracken Peck still lives in the Chestnut Hill home where he grew up. His three young children are budding naturalists who often beg to come to work with him.
He still has some of the shells and birds' nests he collected as a kid. And, yes, he read National Geographic and fantasized about going to many of those places himself some day.
