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Wednesday, 23 November 2005 00:00

Chickadee code cracked

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Chickadee #1: Chick-a-DEE!-DEE!-DEE!-DEE!-DEE!-DEE!-DEE!

Translation: There’s a sharp-shinned hawk behind you!

Chickadee #2: Chick-a-dee-dee-dee-dee-de.

Translation: Thanks. I’m outta here, but you’re cool. There’s only a great horned owl behind you.

Chickadee #3: Chick-a-DEE!-DEE!-DEE!-DEE!-DEE!-DEE!-DEE!-DEE!

Translation: Git off yer feathered little butts and git over here and help me chase this sharpie away!

I’m not extremely fluent in chickadee-ese, but according to Chris Templeton, a doctoral student in biology at the University of Washington, that’s the general idea. Templeton and co-authors published their findings in the journal Science earlier this year.

The researchers spent hours and hours working with a flock of black-capped chickadees in a raptor rehabilitation center. They recorded more than 5,000 “chick-a-dee” calls.

According to Templeton, the calls were highly variable. These variables included number of syllables, spacing of syllables, and the acoustic features of the syllables. The researchers believe that the variables in the call correlate directly to the degree of threat posed by a predator.

In the above scenario, the chickadee number one would be highly concerned over the presence of an accipiter such as a sharp-shinned hawk that regularly takes small songbirds. On the other hand, chickadee number two is not too concerned over a great-horned owl. While the great-horned owl is a much larger predator, it is not often a threat to chickadee-sized prey.

According to the study, small dangerous predators elicited about three-and-a-half more “dees,” with totals up to 23. While not so dangerous predators elicited only an extra half “dee.” The researchers also discovered that the more “dees” in an alarm cry the larger the number of chickadees that gathered and the closer they approached the attacker – in this case, a speaker.

The chickadees showed a lot of discretion in their calls. Large predators that might have a penchant for songbirds got more “dees” than small predators that pose little threat. Templeton added other predators like cats and ferrets and even non-predators such as quail to the enclosure. The results seemed to point to the fact that more danger elicited more “dees.” And more “dees” garnered more support.

Researchers also believe chickadees keep an eye out for flying predators. The team noted that the birds emit a high-pitched “seet” call when raptors like hawks and owls were present flying overhead.

Similar research with other birds has produced the same kind of results. Studies with red-winged blackbirds show that the males call faster and with more intensity, the closer a predator approached its nest.

Black-capped chickadees are the northern cousins of our more common Carolina chickadee. Black-cappeds do make it down the Appalachians to our area but are generally found above 4,000 feet in elevation. They can sometimes be encountered along the Blue Ridge Parkway around Richland Balsam, Waterrock Knob and along Heintooga Spur Road.

The Carolina and black-capped chickadees are closely related and commonly hybridize where their ranges overlap. Around 20 different vocalizations have been recorded for both species and researchers note that there appear to be homologies between typical calls of both species. It is likely that the “dee” calls of Carolina chickadees vary in the same way as the black-capped.

Studies with chickadees show that calls are used for more than just alarms. In the Canadian Journal of Zoology, Christopher Sturdy calls the chickadee vocalizations an avian language. According to Sturdy, call notes are analogous to phonemes – the smallest component of human words. Sturdy believes a chickadee call is similar to a human word and a string of calls is analogous to a human sentence.

The next time you’re in the field and hear a flock of chickadees calling, beware; they may be talking about you.

(Don Hendershot can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..">This email address is being protected from spambots. You need JavaScript enabled to view it..)

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