An ivory-billed woodpecker specimen is on a display at the California Academy of Sciences in San Francisco, Friday, Sept. 24, 2021. (AP Photo / Haven Daley)

Death’s come knocking a last time for the splendid ivory-billed woodpecker and 22 more birds, fish and other species: The U.S. government on Wednesday declared them extinct.

Specimens of the extinct Xerces blue butterfly, in the Field Museum's collection. (Courtesy of Field Museum)

Despite its diminutive size, the butterfly famed for its iridescent wings is a giant within the conservation movement, cited as the first case of an insect extinction that can be attributed to urban development.

Conservationist George Archibald and a crane named Tex. (Photo courtesy of the International Crane Foundation)

Conservationist George Archibald has spent his life working to bring cranes back from the brink of extinction. He joins “Chicago Tonight” to talk about his groundbreaking work which has been recognized around the world.

Illegal Ivory Trade Fuels Extermination of Elephants

At the current rate of extermination, the African elephant could be extinct in the wild in a few short decades. Founder of Save the Elephants Iain Douglas-Hamilton and Chicago Zoological Society president Stuart Strahl join us to discuss what can be done to curb the illegal ivory trade and save these majestic creatures.

Film Documents Extinction of Passenger Pigeon

A century ago, the last known passenger pigeon in existence died. For decades, billions of passenger pigeons filled the sky. A new documentary addresses what happened to the passenger pigeon.

Conservation biologists Curt Meine and Stanley A. Temple discuss species extinction, the importance of biodiversity, and what we can do in Chicago to help out.