The most important bird in the Silver Jackdaw gang is called the sentinel. This bird watches people as they go about their daily business in the villages and towns in the mountains. Silver Jackdaw sentinels recognise those people who have previously lost coins or taken their rings off in public and had them stolen. The sentinels call out to waiting jackdaws and caws instructions to them as to their possible next target. These birds will then track the person until an opportunity comes along for them to steal something shiny.
When the Silver Jackdaws fly back to the cities for the winter, they concentrate on the grassed parts of the cities and parklands where they can eat grubs and insects. At this time of year, the fledgling birds are initiated into the ways of the jackdaw gangs by being paired with experienced jackdaws, who train the younger birds to spot an opportunity to steal a coin or other carelessly discarded shiny object, even when that object is just a ring pull from a can of pop.
This is an extract from the book Animals Evolution Avoided