Illustration: Brandon Ballengée

The last Passenger Pigeon on earth, a female named Martha, died 100 years ago at the Cincinnati Zoo, where she had lived for all of her 29 years. Artist and Audubon Toyota TogetherGreen fellow Brandon Ballengée's response to the species loss is Frameworks of Absence, a series he created by physically cutting and removing birds, including this passenger pigeon, from original historic John James Audubon prints and then framing the prints with the birds missing. "As humans," he says, "we have a very difficult time conceptualizing extinction—even coming to terms with our own short lifespans—let alone thinking that an entire group of organisms could be gone forever." Thousands of people will commemorate Martha's flock in 2014 through two initiatives, Project Passenger Pigeon and The Lost Bird Project, that aim to educate the public not just about this vanished species but also about our role in preventing future extinctions.