Birds’ decisions about what nest-materials to use to build with have typically been considered to be genetically determined. We believed learning may also be important in nest material selection as birds are known to use learning to improve the quality of their decision in many other contexts.
We gave zebra finches lengths of either a stiffer or more flexible sort of white cotton string to build with. After they had some experience of building with their allocated string type, we then gave them a choice of both sorts of string to build with. We observed that those zebra finches that had previous building experience of the more flexible sort of string avoided it and opted to build with the stiffer string, whereas those birds that had only experienced the stiffer string were less choosy. We also noticed that birds who built nests out of the stiffer sort of string required fewer pieces of it to construct a typical zebra finch nest than birds that built nests with the more flexible sort of string, indicating that the stiffer sort of string was a more efficient nest building material.
If birds’ nest-material decisions had been entirely based on their genes then their prior building experience should not have affected their decisions. That it did shows that learning about what materials work best is, as we expected, important in their nesting building decisions.
Read the full story in the Proceeding of the Royal Society- B: http://rspb.royalsocietypublishing.org/content/281/1784/20133225.full