There are cat shelters for unwanted calicos and Siamese. There are dog shelters for discarded beagles and shepherds. Less well known are bird shelters for abandoned cockatoos and cockatiels. KFAI’s Hilde de Roover visited a Midwest Avian Adoption and Rescue Services (MAARS) in the Twin Cities, learning about the people who care for captive birds. Listen to her documentary (“The Parrots Who Landed on MAARS”) at 7 p.m. on July 23.