Above: flying is hard work for birds, producing a lot of heat which they need to get rid of. The tufted puffin, also known as the crested, may have found the answer © Shutterstock.com/Tarpan
TUFTED PUFFINS (FRATERCULA cirrhata) regulate body temperature with their large beaks, an evolutionary trait that might explain their ability to fly for long periods in search of food.
Using thermal imaging cameras to measure the escape of heat from wild tufted puffins immediately after flying, researchers from McGill University, Canada, and the University of California, found that within 30 minutes of landing the birds’ beaks had cooled down by 5°C whereas dissipation from their backs barely registered. Despite accounting for only 6 per cent of the puffins’ total surface area the bill was responsible for 10-18 per cent of total heat exchange.
Paradoxically, birds that live in cold climates (the tufted puffin hails from Alaska) tend to have smaller bills but senior author of the study published in the Journal of Experimental Biology, professor Kyle Elliott, believes that the puffin’s larger beak is down to the energy used when they fly, which potentially produces as much heat as a light bulb.
He said: “Our results support the idea that body heat regulation has played a role in shaping some bird beaks. We think this is also an example of exaptation, which means that an external structure is amplified to serve a new function; much in the same way the desert hare’s ears became bigger to help them cool down.”
The large bill could be a means of dumping unwanted extra heat generated by flying, explained study lead author Hannes Schraft; because feathers provide such good insulation, heat can’t escape this way. “Overheating can be a big problem for seabirds who need to fly long distances to feed their chicks during breeding season,” Ms Schraft concluded.
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