Fig. 2: After the transition to arboreality, foot use has repeatedly evolved in different clades, and is associated with multiple diets.

a Ancestral state reconstruction with a precursor model shows that after a single evolution of a precursor state at the base of all core land birds (Telluraves), foot use has evolved repeatedly, at least 20 times. b, c Skill scores for different orders (b) and songbird families (c). The lower and upper hinges correspond to the first and third quartiles. Whisker extends no further than 1.5 the inter-quartile range, or distance between the first and third quartiles. d Percentage of species for each diet category where there is no evidence of foot use (yellow), evidence of foot use (dark blue) and likely foot use (light blue). Species are considered to belong to a particular diet category if >60% of the diet is of one type⁷². Likely foot use refers to species that belong to families where foot use was confirmed, but those species where not searched. In general, foot use is not associated with only one diet (see Supplementary Table 3).