It started as a rumor in the cafeteria of the Smithsonian Tropical Research Institute in Panama: monkeys on an island in the Pacific were doing something no one had ever seen them do before. But when researchers went searching for these elusive capuchin monkeys, they discovered more questions than answers.

Guests:

Claudio Monteza, Smithsonian Tropical Research Institute fellow and researcher at the Max Planck Institute of Animal Behavior

Brendan Barrett, researcher at the University of Konstanz and the Max Planck Institute of Animal Behavior

Meg Crofoot, director of the Department for the Ecology of Animal Societies at the Max Planck Institute of Animal Behavior. Former Smithsonian Tropical Research Institute fellow

Money is power. But who's on our money - or isn’t - can be just as powerful. While Lady Liberty has graced American coins and dollars for most of our history, it wasn’t until the 1970s that a real woman appeared on a circulating American coin. But that's about to change. Congress recently authorized the creation of twenty new quarters featuring American women from history. But how do we decide whose likeness gets engraved in our national story? And who makes these decisions? We’ll follow the money to find out.

Guests:

Jennifer Schneider, former program manager at Smithsonian American Women’s History Museum, current assistant registrar of outgoing and government loans at the Smithsonian American Art Museum

Tey Marianna Nunn, former director of the American Women’s History Initiative at the Smithsonian American Women’s History Museum, current associate director for content and interpretation at the Smithsonian’s National Museum of the American Latino

Ellen Feingold, curator of the National Numismatic Collection at the Smithsonian’s National Museum of American History

Joseph Menna, chief engraver at the United States Mint

Tim Grant, public affairs manager at the United States Mint

Dave Clark, supervisor of blanking annealing and upsetting at the United States Mint

Did you know a person born on February 29 is called a "leapling"? This special episode is hopping with Leap Day trivia! Like, why do we need an extra day every four years anyway? And will I get paid for working an extra day in February? It's the lowdown on Leap Day in an episode that's as off-kilter as the earth's axis.

Guest:

Bob Craddock, Geologist at the Smithsonian's National Air and Space Museum's Center for Earth and Planetary Studies

They say love is eternal. What about heartbreak? This Valentine’s Day, we bring you some of Japanese theater’s most popular tales of scorned lovers seeking vengeance from beyond the grave — with a burning passion.

Guests: 

From brontosauruses with bronchitis to birds on a wire to flying space rocks and a botched heist at 20 thousand feet. In this episode, Lizzie and Sidedoor producer James run all around the Smithsonian to answer listeners' questions from the Sidedoor mailbag.

Guests:

Lynn Heidelbaugh, curator at the Smithsonian’s National Postal Museum

Sara Hallager, curator of birds at the Smithsonian’s National Zoo and Conservation Biology Institute

Jim Nollman, composer and pioneer of the “interspecies music” genre, conceptual artist, and environmental activist

Cari Corrigan, research geologist at the Smithsonian’s National Museum of Natural History and curator of the Antarctic Meteorite Collection

Sharon Bryant, marketing specialist at the Smithsonian’s Office of Communications and External Affairs

Matthew Carrano, research geologist and curator of Dinosauria at the Smithsonian’s National Museum of Natural History

As long as there have been wars, animals have joined their human companions on the battlefield. But a few have served so bravely they’ve been memorialized at the Smithsonian. In honor of these furry and feathered war heroes, we bring you the tales of dogs, cats and birds who went above and beyond the call of duty. 

Guests: 

Jennifer Jones, curator of military history at the Smithsonian's National Museum of American History 

Frank Blazich, curator of military history at the Smithsonian's National Museum of American History 

Ann Bausum, author of Stubby the War Dog and Sergeant Stubby: How a Stray Dog and His Best Friend Helped Win WWI and Stole the Heart of a Nation 

Scot Christenson, author of Cats in the Navy 

Chris Willingham, president of the United States War Dogs Association

Virginia Hall dreamed of being America’s first female ambassador. Instead, she became a spy. Joining the ranks of the U.S.’s first civilian spy network, she operated alone in occupied France, where she built French Resistance networks, delivered critical intelligence, and sold cheese to the enemy. All on one leg.

Guests:

Sonia Purnell, author of “A Woman of No Importance: the Untold Story of the American Spy who Helped Win World War II.” 

Randy Burkett, CIA Staff Historian

Christina Gebhard, museum specialist at the Smithsonian’s National Museum of Natural History

It’s a song we often hear at the start of the new year. But what does “auld lang syne” even mean? And how did it come to be associated with New Year's Eve? With a little musical sleuthing, we find Charlie Chaplin might have something to do with it…

Guests:

James Deutsch, curator of folklife and popular culture at the Smithsonian Center for Folklife and Cultural Heritage

North American River Otters are popping up in places they haven't been seen in decades and nobody really knows why. As we search for answers we discover a trail of fish heads, poop splats and cuddle parties.

Guests:

Katrina Lohan, head of the Coastal Disease Ecology Laboratory at the Smithsonian Environmental Research Center

Alejandra Morales Picard, psychologist at Montgomery College

Rebecca Sturniolo, assistant curator of the America Trail at the Smithsonian National Zoo

Patty Storms & Morty Bachar, otter neighbors

When Maggie Kuhn was forced to retire from the job she loved at age 65, her colleagues gave her a sewing machine as a parting gift. Outraged, she shut the sewing machine in a closet and, instead, stitched together the first-ever movement against ageism in the U.S. The Gray Panthers would galvanize gray haired citizenry and youth alike to challenge the way Americans think about aging. 

Guests:

Emily Krichbaum, founding director for the Center for Girls' and Young Women's Leadership at Columbus School for Girls and scholar of women’s history

Paul Nathanson, founder and former executive director of Justice in Aging (formerly the National Senior Citizens Law Center), a national advocacy group for the elderly poor

Jack Kupferman, president of Gray Panthers NYC