In the days when milk was delivered each morning to the doorstep of almost every house in Britain, enterprising great tits sometimes learned to peck through the foil bottle-tops to get at the goodies beneath. These avian pioneers were quickly imitated by others, with the result that cream-pillaging populations emerged in several parts of the country. Cream-pillaging was one of the first recognised examples of animal culture: the transmission of behaviour from one individual to another, so that it persists down the generations. But, oddly, it was never followed up experimentally in the wild, to understand the nuances of the process.
展开▼
