Chickadees are members of the Paridae family, which includes not only chickadees but also titmice. In North America, those species without crests are called chickadees, while those with crests are called titmice. North American has 7 species of chickadees: Black-capped, Mountain, Carolina, Boreal, Chestnut-backed, Mexican, and Gray-headed. In Colorado, we have the first 2 species. (The photo on the left is a Mountain Chickadee; on the right, a Black-capped Chickadee. Thanks to Wikimedia Commons for free access to such nice photos!)
The most common call, as noted in the article, is the eponymous “chick-ah-dee-dee-dee.” During breeding season, both species of chickadee has slightly different but distinguishable songs. The Black-capped Chickadee (BCCH) sings a clear “Hey, sweetie,” where the first syllable is about 1/2 to 1 note higher than the last 2 syllables (which are on the same pitch). If you’re familiar with BCCHs in the East, you may note a subtle difference between the eastern and westerner song: In the East, they sing a 2-note “fee-bee” while in the West, you’ll hear the 3-note “hey, sweetie.” You can hear a sample of both the song and the call here. The Mountain Chickadee (MOCH) song is a clear whistled “dee dee dee” all on the same pitch. Both its song and its call can be heard here.
Both species are cavity nesters. BCCH will excavate their own cavities in soft wood, although they’ll also use nest boxes or other cavities. MOCH are what is called “secondary cavity nesters”: They don’t excavate their own cavities but use naturally occurring cavities or those made by primary cavity nesters such as woodpeckers. On our property, we have a number of nest boxes and every year, we typically have 2 or 3 pairs of MOCHs raising a brood in them. You can see photos of nests, eggs, and nestlings in our boxes here.
Unlike many other species, a surprising amount of research has been conducted with chickadees (mostly BCCH, but some with MOCHs). For instance, research conducted by the University of Colorado Boulder examined the impact of excluding chickadees and other small insectivorous birds from a stand of ponderosa pines in the Manitou Springs area. Compared with a similar area that allowed the insectivores to glean insects, the wood growth and foliage in the experimental area was significantly hampered by the lack of insectivores. Read more about this study here.
Specialized leg muscles enable these birds to feed acrobatically (they often feed while hanging upside down), making them particularly adept at finding food in difficult locations, such as buds at the ends of twigs and insects on the undersides of leaves. Chickadees also come to seed feeders and, as noted in the article, they carefully choose the plumpest seed, often discarding several before selecting one and flying a short distance to cover. To open seeds, they anchor them with their feet and hammer them open with their bills. You can read more about the research that demonstrated their propensity for heavier seeds here.
Chickadees are primarily non-migratory, remaining in the general area of their breeding range throughout the winter. They use regulated nocturnal hypothermia year-round, to save energy on cold nights. By lowering its body temperature 5 – 20 degrees F at night, it can save significant amounts of energy (estimates range from 7% to 50%). Read more about this here. In addition, they store food and have exceptional spatial memory to relocate cached items.