Fig. 1
From: Adaptation and constraint shape the evolution of growth patterns in passerine birds across the globe
Relative development of traits at fledging (top) and peak growth rates (bottom) in relation to fledging age in passerines. In relative trait development, the value of 1 means that the trait was developed at 100% of adult value at fledging, and this is designated by a horizontal line. Growth rate is the peak growth rate (K parameter) from a sigmoid growth model (either three-parameter U-Logistic or four-parameter U-Richards model). There are two lines for mass growth (for both Logistic and Richards models); one is for complete nestling data, while the other is for nestling body mass truncated at 70% of adult mass. These relationships remained unchanged when growth rates and fledging age were adjusted for allometry (see Figs. S12–S17 in Additional File 2 and Tables S4 and S5 in Additional File 1)