Population dynamics, recruitment, individual quality an d reproductive strategies in Common Terns Sterna hirundo marked with tran sponders

From 1992 to 1999, we used subcut aneously injected transponders, enabling remote an d 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 an d 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 pairs, mean recruitment age 3y) . Data on condition, fate, reproductive performance and output were gathered year by year and cont ri buted 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 an d 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%) an d increased with arrival asynchrony of mates . Divorced terns tended to ch an ge 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 ., H . Wendeln & J . Gonzalez-Solis 2001, Ardea 89(special issue) : 241-252.