It's nothing to worry about! Almost all big yellow birds get the birdy pox!
My Bella is home on summer break between ESY and her new school year. I turned on Sesame Street on HBO - and clicked CLASSIC - so that she could watch the fun, musical, kind, educational Sesame Street that I remember from when her sisters watched in the 1990s. One of the episodes available caught my eye - "Big Bird Catches the Birdy Pox."
Below is a clip from Season 27, back in 1995-96 in which Big Birdy gets "the Birdy Pox." The doctor uses a soothing, compassionate voice to tell him, "It's nothing to worry about. Almost all big yellow birds get the Birdy Pox!" Imagine that. Before the marketing vaccine machine took over, chicken pox was common childhood disease whose prescription was exactly what the doctor told Big Bird: Rest in your nest.
Today, kids unvaccinated for the chicken pox have been EXPELLED from school in both New York and California. This has happened in a mere 25 years. Chicken pox is a scourge that brings scorn and shame to mothers and kids alike. Rest in your nest is now "No school, you fool." The sunny day is now sad.