Results
We found a total of 40 colour-variable species and 59 rare colour variants (Figure 2). Rare colour variants were primarily found in the Felidae (N = 20), Mustelidae (N = 15) and Canidae (N = 11) families. Hyaenidae was the only carnivore family for which no colour variants was detected. Twenty of the colour variants were described as leucistic (34%), and seventeen as melanistic (29%). The average frequency of colour variants was 20% in the population where it occured, based on data from 16 publications.