Age ratio and survival of Common Rosefinch (Carpodacus erythrinus, Passeriformes, Fringillidae) in a local population based on ringing data

Abstract

The ringing data on Common Rosefinch obtained during thirteen field seasons (2002–2014) at the National Park “Russky Sever” (Vologda region) are analyzed. Birds were trapped in two sites 59 km apart. The age of the birds (yearlings or first breeders and adults) was determined according to the plumage color in every male captured with mist nets. The apparent survival rate of adult individuals was determined using two methods: according to the ratio of males’ age and the CJS model (Lebreton et al., 1992; Bursky, 2011). A total of 713 captures of 657 individuals were analyzed. The ratios of ages in the males from the sites studied did not differ; yearlings amounted to 56% of all males. The rate of survival in the males based on the age ratios was estimated at 44 ± 2%. The apparent survival rate obtained using the CJS model was significantly higher (61 ± 6%). The survival rate of adult rosefinches in two sites did not differ and did not depend on sex. Literature materials on the age ratio and survival of rosefinches in local populations are analyzed. There is a suggestion that the mismatch of the survival rates obtained by two methods and the high proportion of yearling males in the banding captures can be explained by the fact that the majority of individuals of that age category did not participate in nesting.