An Ostentatious Air Conditioner: The Toucan's Big Beak

By Eliza Strickland | July 23, 2009 5:23 pm

toucanThe toucan’s big beak has been an object of fascination for centuries: In the late 1700s a French naturalist called it a “grossly monstrous” appendage, and later Charles Darwin contemplated its possible purpose. Why should the bird have a beak that accounts for 40 percent or more of the total surface area of its body? Among the suggestions are that it is useful for peeling fruit, for attacking other nests or as sexual ornamentation [The New York Times]. Now a new study has revealed the beak’s true purpose: It serves as a giant air conditioner, helping the bird keep cool.

Animals have a range of ways including layers of fat in polar bears and large skin surfaces in elephants to stay cool or keep warm in harsh environments. [Lead researcher Glenn] Tatersall and colleagues found the toucan can lose up to four times as much heat from its beak than it produces at rest — the most reported for any animal [Bloomberg]. The researchers found that the toucan’s bill beats out the elephant’s ears in its ability to change the animal’s body temperature; it can rapidly adjust the internal thermostat by as much as 27 degrees Fahrenheit, Tattersall says.

The toucan has a network of blood vessels in its beak, and researchers say that network is the crucial air conditioner component. Tattersall said: “By altering blood flow to the bill’s surface, toucans can conserve body heat when it is cold or cope with heat stress by increasing blood flow. “Essentially, the large surface area of the bill, and the fact it is not insulated, means that the blood flowing through is able to release heat into the bill, thus cooling the bird. This blood-derived heat in the bill is then dissipated into the air [BBC News]. 

For the study, which will be published tomorrow in the journal Science, the researchers studied the South American toco toucan by keeping the birds in a temperature-controlled chamber and imaging them with heat-sensing cameras while gradually changing the room’s temperature. They found that below an ambient temperature of about 60 degrees Fahrenheit, the bill was relatively cold, indicating that the blood vessels to it were constricted. But above that temperature blood flow to the bill increased. “The animal is dumping the heat, using the bill as a thermal window,” Dr. Andrade said [The New York Times]. 

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Image: Glenn Tattersall

  • http://- Manoj Bhardwaj

    God is Infinite.. His creations are equally matching.. The Toucan is a visible medium to appreciate God’s Infinitely vast Systems created for His Creations’ well being.
    We definitely need to learn to appreciate His World.. rather than bragging about our worlds limited to Wall Streets, White Houses and Capitol Hills…
    The ingenuity created in the Toucan’s cooloing system is Beautiful !!


  • Zachary

    Troll? Poe? Who even knows anymore.

  • robot makes music

    It’s called evolution, bro. Look it up sometime.

  • Roberto Ruth

    I’m purely curious and will not vocalize my beliefs. but I wonder Manoj; do you belive we are equal, or above animals? I don’t blame you if you don’t answer this question. Thank you.

  • Ben

    Actually, the article is a little misleading. Both Dr. Tattersall and Dr. Weckstein, an evolutionary biologist at the Field Museum of Chicago, say that it probably evolved for some other reason, and that the cooling is just an added benefit. Check my website link for the NPR article and interviews.

  • YouRang

    Surely bird beak isn’t a very good conductor. So how does the bird manage to maintain his blood pressure when he’s dumping heat through these miles of blood vessels? In particular, how does he fly? (Flying is presumably when he would need to dump heat the most.)

  • zachary

    Agreed Ben, nature is pretty frugal. Such a feature likely doesn’t serve a sole purpose as this article appears to hint at.

  • Ken Haney

    I’m still looking for an explanation of how this animal decided a big beak would be just the thing and then instructed its body to develop it evolutionary style. How did this all wise bird convey to its offspring that this was now the plan and would they please comply and stay the course. Design requires a designer and this bird, though amazing, doesn’t have that capacity. Matthew 6:27

  • Art

    @Ken Haney

    Tell me your thoughts on the mosquito. Disease transmitter, irritant, or food source for bats, etc?

    Also, how do you feel about MRSA and H1N1? Has god created them recently or have they been lying dormant waiting to cause a ruckus?

  • zachary

    So basically Ken, you’re looking for a 101 college course in biology? They go over this stuff in natural selection and genetics, take you hopefully about a day to get up to speed.

  • SanAntonio_AC

    Natural air conditioner…..!!!!!! now that is something different, nature has developed itself according to need from billions of years, even if one gives his whole life even then he can’t figure out there things.

  • Matthew Egan

    … Evolving thoughts from everyone. I really love this post. Agreed a natural air conditioner is mother nature at it’s finest.


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