New Caledonian crows use tools to extract prey from dead wood and vegetation [1,2]. Several other animal species are known to use tools, but these tropical corvids (crows) stand out. New Caledonian crows have a very rich range of unusually complex tool designs. In fact, they are the only species, other than humans, to craft hooked foraging tools. It has been suggested that this technological sophistication may be due to the cultural transmission and accumulation of information.
We investigated whether crow social networks could support the spread of tool-innovations. Using new tracking technology, we examined the social networks of wild crows, recording when birds met each other and for how long . Our study showed that young crows may learn not only from their parents, but also from many unrelated crows in the population. This is an important step in testing the existence of ‘crow cultures’.
 Rutz, C. et al. (2007). Video cameras on wild birds. Science 318, 765.
 Rutz, C. et al. (2010). The ecological significance of tool use in New Caledonian crows. Science 329, 1523–1526.
 Rutz, C. et al. (2012). Automated mapping of social networks in wild birds. Current Biology 22, R669–671.