The Stokes Guide to Bird Behavior Volume I describes the context of the dee-dee call as "Given in conflict situations and often followed by other aggressive actions such as a chase; used especially in territorial skirmishes." Bird calls and songs often have a "message" and staying attuned to what we hear can help clue us in to events or happenings in the birds' lives.
The dee-dee-dee calls from the chickadees were persistent and urgent. They were entering the nest, cautiously as always (they always scout from a nearby tree and then fly straight into the box lickety-split. No hanging around the front door!) Had something entered the hole and attacked the chicks?
Dee-dee-dee. Dee-dee-dee. My next nestbox is still 2 days away - what if something happened?So many things can happen to a box full of baby birds. Even though I've done everything I can to protect them, any number of things could have happened. The box is far enough from trees that a chipmunk couldn't make the jump but could a Red Squirrel? The portal protector is 1-1/2" diameter - if they made the jump, could they squeeze in?
The jays are numerous but too big to enter. (I'm worried about the jays when the fledglings leave the nest!) Both a downy and a nuthatch have checked out the box - could (or would) they prey on the chicks? The junco I've seen on the box is not a likely threat; as a non-cavity nester, they'd be reluctant to enter the hole.
But I had to check, I couldn't stand not knowing! So I approached the nestbox calling out and rustling branches. My approach attracted both parents to the vicinity of the box. They certainly were protective! One had a mealworm in its mouth and entered the box and from inside the box I heard the sweetest sound a bird landlady can hear: petite little cheeps!I was elated! There's still live babies in the nestbox and I didn't have to disturb them to find out!