The Carlisle Mosquito Online

Friday, October 18, 2002

Features


Black-capped Chickadee
Written and illustrated by Nicky Pearson

Family: Paridae, chickadees and titmice

Where Found: All over Carlisle. Common in wooded areas in urban and rural locations from the Mexican border through western Canada to Alaska, from the East to the west coast of North America.

Characteristics: Cute. Males and females look alike. Distinctive black cap and triangular black "beard," white mask and upper breast, which merge to a buff underbelly, light gray back and slate wings and tail. About 4" long. Specialized leg muscles allow them to hang upside down.

Look-alikes: Blackpoll Warbler. Black-capped Chickadee is smaller and doesn't have the distinctive stripes that the Black Poll Warbler has on its sides. In addition, the Black Poll Warbler only passes through Carlisle area during spring and fall migration, while the Chickadee is a year-round resident.

Behavior: The male and female leave their flock to nest together in a hollow tree ­ either they find an existing hole or they dig one out for themselves in soft or rotting wood. This also serves as a courtship ritual, along with mutual feeding and preening. The nest is constructed at the bottom with coarse grasses and such, and then lined with soft grasses and animal fur. They lay six to eight eggs that hatch after about two weeks and when the young have fledged they flock as a family or join another family. In dense woodland they keep in contact with each other with a complex variety of vocalizations. (Biologists at the University of Alberta have distinguished over 350 different sounds in the black-capped alone!) When the young are a year old, they choose their mates. Like many other birds, they are believed to mate for life. There are three species in the Poecile genus, the other two being the Carolina Chickadee (P. carolinesis) and the Mountain Chickadee (P. gambel). Hybridizations can occur in these species. They also may flock with other species of birds, including other insectivores such as woodpeckers and nuthatches. During times of extreme food shortages, they join together in huge flocks called an "invasion" and move to a more desirable location. Aside from the "invasions," Black-capped Chickadees are non-migratory and weather out the coldest of temperatures, including the -40 and below weather in western Canada. Behaviorists have discovered that in extreme cold they burrow under the snow and go into a mini-hibernative state until the temperature rises again.

Food: They are omnivorous and their diet consists of seeds and arthropods (spiders, insects, etc.) including the larval and egg stages. Chickadees prefer seeds and nuts with high fat content for hoarding, such as sunflower seeds and peanuts. They hoard them for hard times and keep them in stores called "caches" under lichen and loose bark. This provides a food store that they go to in harsher and more desperate times in the winter. This implies that these small birds have excellent survival skills and spatial memory.

Vocalization: Animal behaviorists at University of Massachusetts in Amherst have discovered that the sounds that chickadees make are to a large extent learned, so that isolated populations (in a lab or island populations and chickadee populations spread across North America) have different dialects. The most notable signature sound is that which they are named after, which goes "chick-a-dee-dee-dee." They have discovered that, on the islands of Chappaquiddick and Nantucket, the song is noticably different; their song is more of a monotone "fee-bee-bee" sound, and (where I am from) in Alberta, Canada, the song can have any number of "bee"s at the end, so it sounds like "fisk-a-bee-bee-bee-bee-bee" with decreasing volume.

Sources: http://www.50states.com/bird/chickade.htm, The Sibley Guide to Bird Life and Behavior, David Allen Sibley.


2002 The Carlisle Mosquito