Fig. 2

Forest plots of meta-analytic estimated standardized effect sizes (Z _r, blue triangles) and their 95% confidence intervals for each effect size included in the meta-analysis model. A Blue tit analyses: Points where Z _r are less than 0 indicate analyses that found a negative relationship between sibling number and nestling growth. B Eucalyptus analyses: Points where Z _r are less than 0 indicate a negative relationship between grass cover and Eucalyptus seedling success. The meta-analytic mean effect size is denoted by a black circle and a dashed vertical line, with error bars also representing the 95% confidence interval. The solid black vertical line demarcates effect size of 0, indicating no relationship between the test variable and the response variable. Note that the Eucalyptus plot omits one extreme outlier with the value of −4.47 (Supplementary Material A, Figure A.2) in order to standardize the x-axes on these two panels