Changes in the number of Tree Sparrow nestlings in Ueno Zoological Gardens, central Tokyo during 1977-1984 and 1990-1995

I banded Tree Sparrow Passer montanus nestlings in the West Garden of the Ueno Zoological Gardens in central Tokyo from 1977 to 1995. The banded nestlings appeared to be over 9-10 days old. The average number of nestlings in the nest was compared with the banded years, banded months and the number of broods in the nest. The average number of nestlings in the nest were greater in 1970-1980th than 1990th. There were significantly different among banded years and months.