Black-capped chickadees are social
Each winter, these birds form curious social flocks:
- Open-door policy: Other species join chickadee flocks—including nuthatches, vireos, warblers and woodpeckers. Birders look and listen for chickadee flocks during spring and fall migrations, because it can yield sightings of less common birds.
- Complex communicators: Chickadees have many complex calls and songs. Their namesake chick-a-dee-dee-dee call can serve as a warning to the flock about predators. The more dee notes included, the higher the potential danger.
- Brain control: In the fall, they let old neurons die to make room for new memories. This allows them to keep up with changes in their flocks and remember new food storage locations.