Novel aspects of nest defence in stingless bees

Defence against predators is fundamental to increasing an organism’s fitness. My thesis explores this central theme in behavioural ecology using stingless bees as study organisms. The thesis contains a general introduction (Chapter 1), three data chapters (2-4) and a final discussion (5). Chapter 2 is a comparative study of aggression in nest defence among stingless bee species, and describes a new form of nest defence, suicidal biting, which is most prevalent in the genus Trigona. Chapter 3 describes a remarkable behaviour in Partamona helleri, which crashes head-first when entering its nest. An experiment suggests that this behaviour helps to avoid predation at the nest entrance. Chapter 4 studies nest defence in the hovering guards of Tetragonisca angustula, and demonstrates that through coordinated vigilance, a group level behaviour rarely observed in animals, the ability of the group to detect predators is enhanced.