The Relationship Between Clutch Size And Breeding Success Of Great Tit In Secondary-forest

The author had studied the relationship between clutch size and breeding success ofGreat Tit in secondary-forest of Zuojia nature protection area in Jilin Province betweenFebruary and June of 2005. The result suggests that the relationship between the clutch sizeand breeding success of Great tit is prominence. There are two stages before clutch day of thegreat tit. There is correlation between the clutch size and the hatching date of the first egg.Generally speaking, the date of the first egg is much earlier, the clutch size is much more. Theaverage clutch size of Great Tit in the artificial nest is 10.31±1.27. It is more than the clutchsize of the nature nest. The variance modulus of the clutch size is 0.1215. The ordinary clutchsize of Great Tit is ten or eleven. The ordinary laying date is ten days or eleven days. Thecorrelating analyzing between the clutch size and egg weight or egg length suggest that it isnotability negative correlation. There is not notability correlation between the clutch size andthe laying day. It is suggest that the hatching days of ten or eleven eggs are shorter than theaverage clutch size in the studying of the hatching days in different clutch size. Hatching ratioof ten or eleven eggs is smaller than the average hatching ratio. And hatching ratio of nine ortwelve eggs is smaller than the average hatching ratio. The mean feeding period of Great Tit is14.83±1.83 days. There is not remarkable correlation between brood size and the feedingperiod. The fledged rate is high, the number of fledging chicks are equal to brood size whenthere is no disturbance, so parents can feed successfully all the fledging in the reproductivephase until they fledged if there are no human disturbance and prey and other influence. Theresult indicate the optimized clutch size is 11 in the nest box by analyzing the reproductiveparameter such as hatching period, hatching rate, feeding period, fledged rate, fledgling massand number fledged of 10 and 11 clutch size. This work indicates that the correlation betweenthe clutch size and reproductive success of Great Tit is remarkable. Clutch size effects thewhole reproductive phase and efficacy, and it is the main factor of affecting the reproductivesuccess of Great Tit.