Population dynamics, recruitment, individual quality and reproductive strategies in Common Terns Sterna hirundo marked with transponders

From 1992 to 1999, we used subcutaneously injected transponders, enabling remote and automatic annual identification with the aim of performing an integrated population study of a Common Tern Sterna hirundo colony. Within a few years, population parameters and their inter-year variation could be calculated with a high degree of accuracy (adult return rate 91%, subadult return rate 35%, breeding success 1.3 fledglings/pair/y, mean recruitment age 3y). Data on condition, fate, reproductive performance and output were gathered year by year and contributed greatly towards the detailed study of many questions in behavioural and population ecology, such as individuals’ quality, prospecting and recruitment. The arrival time of prospectors and recruitment age were related to body condition. The high body mass of adults increased their reproductive performance and output. Divorce rate was low (18.9%) and increased with arrival asynchrony of mates. Divorced terns tended to change territories, whereas territory fidelity in general was high. The future focus of this ongoing study is reproductive value, senescence, lifetime reproductive success, fitness, and questions related to genealogy

Becker P.H., Wendeln H. & Gonzalez-Solis J., ARDEA 89 (1): 241-252.