Black-capped Chickadee

Black-capped Chickadee

Black-capped Chickadee

Text and photos by Dan Gleason, ©2009

For those of us who live in the northern part of North America, the Black-capped Chickadee is likely a well-known backyard visitor. Named for the black on the top of its head, it also has a black throat, and a broad triangular patch of white between the cap and throat on each side of the face. The name “chickadee” also describes calls given by these birds. Both male and female utter a buzzy “chick-a-dee-dee” call, and males also have a clear whistled song that is the same throughout their range except in two locations: Martha’s Vineyard (Massachusetts) and here in the Pacific Northwest. In each of these two locations, males sing a song that is slightly different than chickadees throughout the rest of the country. We don’t fully know why, but it is likely due in part to isolation of the populations without an opportunity to mix and interbreed.

To us, male and female chickadees look identical, but to other chickadees, the white cheek patch of the male looks different than that of the female. There are over 150 species of North American birds in which males and females look alike to human eyes. But, at least 92% of these species appear different in ultraviolet light, which birds can see, but we cannot. We are just beginning to understand how different the visual world of birds is when compared to humans and we are finding that bird vision is greatly superior to human vision in many respects.

Chickadees are considered non-migratory since their populations do not have large, seasonal geographic changes (i.e., they don’t “go south” for the winter), but individuals may often wander over a broad area within their range. Black-capped Chickadees in the Willamette Valley are present throughout the year and many individuals that you see in January are likely to be the same individuals seen in July. Now, you may be saying, “I don’t have chickadees in the summer, they only come to my feeder in the winter.” I’ll bet that if you look closely in your neighborhood, you would find chickadees present all year, but perhaps just not visiting your feeder.

In winter, chickadees depend more on seed for food and will often take black-oil sunflower seeds from feeders. (Keep feeders full of these seeds as chickadees and many other birds love them.) In fact, the digestive system of a chickadee changes from season to season, reflected by a change in their diet. They can more easily macerate and digest seeds during the winter when their gizzard is enlarged and well-developed. Like all birds, chickadees have a two-chambered stomach, with the gizzard being the muscular rear portion that thoroughly grinds seeds and hard materials. The front portion is called the proventriculus and it secretes digestive enzymes and acids to help digest animal material, such as insects. As spring approaches, and seeds become less available, the gizzard decreases in size and and the glandular portion of the stomach enlarges, making insects more easy to digest. So, rather than come to your feeder for seed, chickadees mostly glean insects from the surfaces of trees and shrubs. Keep in mind, however, that there are few absolutes in nature and you might occasionally see a chickadee taking seed in the summer, but usually much less often than in winter.

There are other reasons that chickadees can be more easily seen in winter. During the late fall and winter, when the leaves have fallen, chickadees are less hidden by foliage, and they forage over a larger home range in search of seeds, plus, they are much less secretive during these non-breeding periods. So, take a moment to look and listen closely, at all seasons, and you will probably discover that Black-capped Chickadees did not “arrive for the winter,” but are actually present all year long.

Many of us tend to equate small-size with frailness, but these small birds are anything but frail. Black-capped Chickadees are found year-round in places that experience severe winter cold and snow. To survive cold winter nights, chickadees can lower their body temperature by as much as 20° F. Such a large drop in body temperature saves a huge amount of energy that would otherwise be required for survival.

Chickadees are seldom found alone, preferring to form small flocks of 6-14 birds. Within each flock are mated pairs that break away from the flock long enough to breed in the spring and early summer. Unpaired individuals, or “floaters,” will often replace a fellow bird’s mate that dies during the breeding season and will carry out the role of the missing parent by feeding and tending to the young of their newly acquired mate. During the non-breeding season, other species such as nuthatches mix with chickadees and are benefited by this association. Alarm notes given by the chickadees can serve as a warning system for these other birds, some of whom have no warning calls of their own.

Chickadees are delightful visitors to attract to your yard. They will readily come to black-oil sunflower seed and to suet. Once accustomed to your feeding station, they will often come within a few feet, if you stand or sit quietly nearby. Such lively visitors add an element of cheer to any backyard.

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