Effects of Parental Investment during Nest Building on Reproductive Efficacy of Great Tit

In 2009 we conducted a study on the relationship between parental investment during nest building and reproductive efficiency of Great Tit inside artificial nest box in a secondary forest at Zuojia Natural Reserve,Jilin Province.The average weight of nest material was 33.90±13.44 g.There existed significant difference in nest material weight among different reproductive individuals,which showed that different individuals of the Great Tits made different nest building investment.The breeding time of the Great Tit varied significantly.But there was no significant correlation between nest material weight and the initial egg date,and later breeding individuals did not reduce nest investment.There existed significant positive correlation between nest materials weight and clutch size(r=0.292,P=0.034) and nestling size(r=0.294,P=0.033),and the heavier the nest material,the bigger the clutch size,and the more the hatching,which indicated that the Great Tit could adjust clutch size and hatching rate by increasing nest building investment.However,there was not an obvious correlation between nest materials weight and fledging size,which indicated that there maybe exist other ecological factors influencing fledging success of Great Tit.