Table 1.
Test of the variation in yolk progesterone (in pg/mg) concentrations and total yolk progesterone (in ng).
Figure 1.
Relationship between female body mass and (a) yolk progesterone concentration and (b) total yolk progesterone.
Figure 2.
Variation in (a) yolk progesterone concentration and (b) total yolk progesterone according to egg category (white boxes: A-eggs; grey boxes: B-eggs) and the date of laying onset.
Boxes show medians, 25% and 75% quartiles for each day; whiskers indicate the range between the 10th and 90th percentiles. •: Data outside the 10th and 90th percentiles. Sample sizes are given under the boxes in the lower frame. Significance of paired t-tests with egg category (A- or B-eggs) as the grouping variable is presented above respective boxes for each date of laying onset; NS: P>0.05, *: 0.01<P≤0.05, **: 0.001<P<0.01, ***: P<0.001.
Figure 3.
Intra-clutch ratios of (a) yolk progesterone concentration and (b) total yolk progesterone between A- and B-eggs according to the date of laying onset.
The solid lines are univariate regression models predicting ratios of yolk progesterone concentration or total yolk progesterone from the date of laying onset and dashed lines represent the ratio expected in the absence of any difference between A- and B-eggs. n = 60 clutches.