At one time, passenger pigeon flocks crowded the skies over the U.S. like clouds. Over 100 years ago, the pigeons were hunted out of existence. Now, a new study shows North American bird populations have decreased by 29% since 1970, almost 3 billion fewer birds. David Pearson, a research professor in the Arizona State University School of Life Sciences explains what’s happening to birds.
"Nova" explores new discoveries and how we have come this far on Wednesdays at 8 p.m. on Arizona PBS.
Today's most compelling personalities discover the surprising stories buried within their own families in the sixth season of the critically acclaimed PBS series "Finding Your Roots with Henry Louis Gates, Jr." The series airs Tuesdays at 7 p.m.
On Sundays at 2 p.m., each episode reveals the extraordinary works of William Shakespeare and the still-potent impact his plays have today.