Fig. 1

Relationship between the animal body mass and the Simpson Diversity Index for gut microbiota. Diamonds, circles and triangles correspond to birds, mammals and reptiles, respectively. Small, medium and large sizes correspond to 1, 2–5, >10 individuals, respectively. Green, brown, grey, red, blue and yellow colors correspond to herbivorous, granivorous, omnivorous, carnivorous, piscivorous and frugivorous diets, respectively. Bold fonts make reference to the animals mentioned in the text