Abstract
There have been very few studies of the effects of global climate change on migration and breeding of land birds in Asia (including Japan), compared with those in Europe and North America. In this study, we compared banding records of Barn Swallow Hirundo rustica collected in Japan in 1961-1971 (the 1960s) with those in 2000-2010 (the 2000s) to consider climatic effects on their migration and breeding. From the frequency distributions of the numbers of adults, juveniles, and nestling birds released per day, the timing of rapid increase in adults was about half a month earlier in 2000s than 1960s, but the period of rapid decrease of adults did not vary between these two periods. The distribution of juveniles 40 years ago was almost the same as at present. The timing of rapid increase in nestlings was about half a month earlier in the 2000s than in the 1960s. The ratio of juveniles to adults was slightly smaller in the 2000s than in the 1960s. These results indicate that both arrival and commencement of breeding in Barn Swallows were earlier in the 2000s than in the 1960s, but their departure did not vary between the two periods. Furthermore, their annual fecundity was higher in the 1960s than in the 2000s. Changes in arrival date and commencement of breeding, were expected based on other available information, although it was anticipated that there would be effects of different habitats and study seasons between the two periods. Banding records were considered to be invaluable in assessing departure date and annual fecundity, because of a lack of other information suitable for the analysis of long-term change.
