It is generally assumed that birds' choice of structurally suitable materials for nest building is genetically predetermined. However, a UK study published on Wednesday showed that this is a more cognitively complex activity. The study, published in the Royal Society journal Proceedings B, involved testing that assumption by investigating whether experience affected male zebra finches' choice of nest material. The researchers gave one group of finches a flexible, floppy string to build with, and another group stiffer, more "structurally sound" string. Both groups were then offered a choice between the flexible and stiff string. After a short period of building with relatively flexible string, birds preferred to build with stiffer string while those that had experienced a stiffer string were indifferent to string type. After building a complete nest with either string type, however, all birds increased their preference for stiff string. "Because birds are not considered to be as clever as people, who can learn to use different materials quite easily, the assumption had been that there was a genetic template in the birds' brains," Lead researcher Ida Bailey from the University of St Andrews said: "This shows that actually learning is also very important for their decisions." Proceedings of the Royal Society B is a scientific journal published by the Royal Society in Britain, which publishes research related to biology