Black-capped Chickadee
Poecile atricapillus
The Black-capped Chickadee is one of North America's most common and widely distributed birds. It can be found from coast to coast, covering a significant portion of Canada and the northern two-thirds of the United States. These birds don't migrate; they stay in their range throughout the year. The vocal behavior of Black-capped Chickadees is complex, which would be expected of a social animal. Adults have at least 16 different kinds of vocalizations. Below is a spectrogram recording of many of these vocalizations, taken from multiple birds from the same flock in the same season just outside of Yellowstone National Park.
Fee-bee
The "Fee-bee" phrase (often referred to as a "song") has a dual purpose: it functions as a territorial advertisement and a means to attract potential mates. In addition to males, females also employ the "fee-bee" call, particularly when they are near their nest sites. (The recording is a dual between two male chickadees...listen for the fainter call.)
Gargle
Gargles are typically a sign of heightened aggression, frequently occurring alongside physical confrontations within winter flocks. However, these vocalizations can take on a different meaning in a sexual context. Occasionally, males produce gargles during their dawn chorus performances, and in this context, they are not linked to aggression. Instead, they are often associated with diverse courtship displays and copulation. (The recording is of two different types of gargle given by two different birds during a squabble.)
Chick-a-dee
The Chick-a-dee call has various uses, all conveying the message "come here." It's used when a bird is separated from its mate or flock, during mobbing of a predator (often with many dee notes), as a signal of safety after a predator has left (especially by high-ranking chickadees), and when a chickadee finds a new food source like a freshly filled feeder. More dee notes are added to the call when faced with more menacing predators, and they respond more intensely to playback of such calls.
High Zee
A high-intensity alarm call primarily used when a fast-approaching predator is spotted. Chickadees hearing High Zees sometimes freeze in place until they hear a Chick-a-dee or Contact call, signaling that the danger has passed.
Contact Call
This soft call is emitted almost continuously by undisturbed chickadees of both sexes throughout the year. Its main purpose is likely to alert nearby individuals to the caller's location.
Begging Dee
The Begging Dee call is exclusively emitted by young birds, typically those in the process of fledging. It's used to request food and may also serve as a way to signal their whereabouts