The species body-size distribution in Iberian ants is parameter independent

Macroecology aims to reveal hidden patterns in species-level traits over large spatial scales. One important species characteristic is body size. The parameter used to characterize body size distributions (BSD) for individual data is the mean of any variable representing - or related to - size, including: body length, body mass, forewing length, wing span or cephalothorax length, depending on the animal group. An appreciable proportion (21%) of the species of Iberian ants with workers show varying degrees of different body size (due to polymorphism or by highly variable monomorphism). Taking into account this specific variation in all Iberian BSD, we have explored the effect of a) the range in body size for those variable species, or b) only the maximum attained body size. No effect was detected in either case indicating that the mean dry body mass for individual data in Iberian ants, polymorphic species included, is a robust and adequate means of measuring the macroecological patterns of BSD. The mean dry mass for Iberian ants is 0.72 ± 1.01 mg and the median dry mass 0.30 mg (n = 242). For functional studies of local communities it is probably wise to take into account the variable degree of polymorphism.