Wherever individuals perform cooperative behaviours, each should be selected to adjust their own current contributions in relation to the likely future contributions of their collaborators. Here, we use the sentinel system of pied babblers (Turdoides bicolor) to show that individuals anticipate contributions by group mates, adjusting their own contribution in response to information about inter...

One theory to explain the existence of conspicuous solicitation is that it is a way for young to 'blackmail' carers into provisioning them, by threatening their own destruction. Fledgling birds offer a unique opportunity to investigate the 'blackmail theory', as their mobility enables them to influence the predation risk they face. We investigated a novel solicitation behaviour in fledgling pie...

The German dramatist Carl Zuckmayer once claimed for the story of the Pied Piper of Hamelin a preeminent position among legends that have been influential in both folklore and literature.1 Even those who question Zuckmayer's view might find good grounds for reviewing the legend's history in folkloric and literary tradition. In 1984 the town of Hameln (Hamelin) in Germany celebrated the seven hu...

The German dramatist Carl Zuckmayer once claimed for the story of the Pied Piper of Hamelin a preeminent position among legends that have been influential in both folklore and literature.1 Even those who question Zuckmayer's view might find good grounds for reviewing the legend's history in folkloric and literary tradition. In 1984 the town of Hameln (Hamelin) in Germany celebrated the seven hu...