Just like humans, chickadees are social.
They split up into pairs during the breeding season, but this time of year, they form flocks with other chickadees and often with other birds such as nuthatches and small woodpeckers, and they move through the forest in a group.
By definition, a forest is full of trees, and sight lines are limited.
Occasionally, a little chickadee suddenly realizes that it cannot see its flockmates (if that's a word).
When it feels alone - if it needs help - it gives what ornithologists call a "contact call" - the familiar "chickadee-dee-dee" for which the species was named.
Hearing the contact call, the members of the flock call back. "Chickadee-dee-dee. We hear you. We're out here. We'll help you."
Sitting alone in a broadcast studio, radio hosts sometimes feel a bit isolated. Sometimes they need help.
A few times each year, the radio station puts out a contact call: "We need help. We can't see you Are you out there?" Year after year, members of the IPR listening flock respond to the contact call: "We can hear you. We are out here. We will help you. Chickadee-dee-dee."