Infrared imaging has revealed the amazing fact

Jul 24, 2009 20:31 GMT  ·  By
Toucans use their massive beaks to regulate their core temperature, a new study proposes
   Toucans use their massive beaks to regulate their core temperature, a new study proposes

Scientists studying toucans came across a wondrous revelation recently, when they discovered that the birds sporting some of the most beautiful beaks in the world actually used them to regulate their bodily temperatures. Using infrared cameras and time-lapse videos of a sleeping toucan, the team comprised of Brazilian and Canadian researchers noted significant temperature variations in the beak over the hours, as it gradually became warmer or colder, depending on the core temperature.

Until now, there existed a number of conflicted theories as to why the bird developed such an impressive front end. Charles Darwin was among the first to attempt an explanation, saying that it was most likely an ornament designed to help with the mating process. Other naturalists have proposed that the large beak could have evolved to allow the bird to rip the peel of fruits, while others believe it plays a role in visual warnings, or nest predation. The new investigation, conducted by scientists from the Brock University, in Canada, and the Universidade Estadual Paulista, in Brazil, proposes a completely different explanation, and provides solid pieces of evidence to support it.

“We used infrared thermal imaging technology to assess the surface temperature of the bill of toucans while they were encountering a range of air temperatures from 10C to 35C. This allowed us to measure the exact temperature of the bill,” the BBC News quotes Brock University expert Dr. Glenn Tattersall as saying. He has also been the lead author of a new paper detailing the discoveries, published in the latest issue of the prestigious journal Science.

“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,” the scientist adds. Previous studies have determined that the beak is laced with an intricate network of blood vessels that have the ability to control the amount of blood reaching it.

“Bird bills are not 'dead tissues,' incapable of playing a role in heat balance, but are active contributors to thermoregulation. Birds do not sweat, so must cope with other mechanisms to deal with elevated temperatures,” Tattersall concludes. The team will now focus its efforts on uncovering how the beaks of other birds aid them as far as regulating core temperature goes.