Box-and-whisker plots of flight muscle ratio and wing loading in relation to food load manipulation ability. a flight muscle ratio (FMR). b wing loading (WL). Medians (horizontal lines within boxes), means (■), 1° and 3° quartile (top and bottom horizontal lines of the boxes), as well as maximum and minimum values (○) are shown for the species able to manipulate the food load (AtM-species) and for the species unable to manipulate the food load (UtM). Endpoints of the whiskers represent the lowest datum still within 1.5 × interquartile range of the lower quartile, and the highest datum still within 1.5 × interquartile range of the upper quartile.