Abstract:

The decrease of the Dipper (Cinclus cinclus) in Hungary was analysed using data of a 15 years long intensive capture-recapture program in Northern Hungary. Both numbered aluminum rings and color rings were used; actual recaptures as well as resighting data were analysed. The model selection, fitting of the General Cormack Jolly Seber Model and estimation of the survival and recapture rate was made by using the RELEASE and SURGE programs. There was a continuous decrease in the survival rate during the investigated time period. For the 1978-1983 period the level of the survival rate (S=0.6) was similar to survival in other European populations.. The survival rate was significantly lower for the last, 1989-1992 period, for both sexes. The decreasing trend in the survival rate coincided with the decrease in rainfall in the breeding area in Hungary, which caused adverse environment conditions for this species.