Figure 1.

Log clutch mass as a function of Log female body mass in birds. (a) Comparison of (blue circles) paternal, (yellow triangles) maternal (same relationship, lines are superimposed) and (white squares) bi-parental care with (pink diamonds) dinosaurs. (b) Comparison of (blue circles) altricial and (yellow triangles) precocial clutch masses. Dashed lines are prediction intervals. (c) Comparison of types of parental care in the Charadriiformes (symbols as in (a)). Vermillion solid line is for paternal care from 1A, dashed line is for ratites.