Natura Croatica
Issue number: Natura Croatica, Vol. 15 No.4
Gustoća gnijezda, veličina pologa i dimenzije jaja sive vrane (Corvus corone cornix)
Authors: Zdravko Dolenec
Authors and affiliation
Abstract
In 2005 the variation of clutch size of tree sparrows Passer montanus was investigated in the Mokrice rural area, north-western Croatia. Average clutch size of first clutches was 5.00 eggs (SD = 0.62), of the second 5.36 eggs (SD = 0.66) and of the third 4.86 eggs (SD = 0.71). Repeatability (r) of clutch size in first, second and third clutches (within-year) was significant (p = 0.005). This means that 33% of the variation in clutch size is due to intraindividual variation of genetic factors (intrinsic »female quality«).
Keywords
Tree Sparrow, Passer montanus, clutch size, repeatability, north-western Croatia

