TY - JOUR AU - L. V. Sokolov AU - A. P. Shapoval PY - 2018/12/22 Y2 - 2024/03/29 TI - Long-term dynamics of age ratios in short- and long distance migrants during autumn migration on the Courish Spit of the Baltic Sea JF - Acta Biologica Sibirica JA - abs VL - 4 IS - 4 SE - Articles DO - 10.14258/abs.444878 UR - http://journal.asu.ru/biol/article/view/4878 AB - The ratios of adult and young birds during autumn migration on Courish Spit of the Baltic Sea at 25 short- and 19 long distance migrants trapped from 1962 to 2016 was analysed. The comparative analysis showed that the proportion of adult individuals among the birds caught in Rybachy-type traps was significantly higher at short distance migrants (19,4%), than at long distance (5,4%). At the species migrating mainly daytime, the proportion of adult birds was higher, than at nocturnal migrants (24,3% against 7,4% at short distance and 7,4% against 4,5% – at long distance migrants). At the majority of species considerable interannual fluctuations in the ratio of adult and young birds were revealed. However significant long-term trends in change of this ratio were revealed only at 3 species of short distance and one long distance migrants. The proportion of the young birds caught in autumn was significantly connected with average air temperature in the Baltic region in the spring and at the beginning of summer (June): the temperature during this period was higher, the large ratio of young migrants was present at autumn catching. Such correlation was revealed at 8 species of short- and 2 long distance migrants. We believed that annual variation of the age ratios depend, first of all, on different levels of reproduction success of adult birds in population. ER -