loading...
Canwest News Service
While the breakfast cereal-peddling Toucan Sam may have followed his nose to find Fruit Loops, it seems his feathered friends have another use for their huge honkers.
Scientists at Brock University in St. Catharines, Ont., have found that toucans use their colourful beaks to regulate body temperature. The bird’s huge schnoz was previously thought to be used to attract the ladies, and to munch on tasty fruits and insects, but now it seems to have another use — a portable radiator and air conditioning unit.
In an article published in the July 24 edition of the journal Science, Brock University researcher Glenn Tattersall revealed how the tropical bird species Toco Toucans, which don’t sweat like humans, respond to warming and cooling air temperatures.
“An elephant uses its ears to dump heat,” he said. “Mice use their tails. Rabbits use their ears. Toucans use their bills.
“Essentially, the large surface area of the bill, and the fact it is uninsulated, means that the blood flowing through is able to release heat into the bill, thus cooling the bird,” said Tattersall in an e-mail exchange from Tokyo, where he is attending a conference on thermoregulation. He chose to study the Toco Toucan because it has the largest beak, which can make up half of its body surface area.
Using an infrared thermal camera, Tattersall and his research colleagues in Brazil produced striking images which show that a toucan’s giant bill — which is made of keratin, like human fingernails and is thus much lighter than it might appear — acts as a heat exchange organ, adapting to temperature change and helping the bird regulate its body heat.
Tattersall and his colleagues found when the birds are cold, they can reduce their heat loss by contracting the arteries in their bills to reduce the blood flow. If the temperature outside is too warm, they expand the arteries to increase the heat that escapes from their bills, thus cooling them.
Shawn St. Michael, curator of birds at the Oregon Zoo, said he’s not surprised to hear that toucans have adapted to their environment, adding that it highlights the need for humans to maintain and conserve those habitats.
“It gives us a very deep appreciation of how over millennia, these animals have adapted to deal with the specific environments they’re in,” he said. “As a result, when those environments change, it has an almost immeasurable impact — and frequently a detrimental impact — on the species themselves.”
