Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts. Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations, with variations in depth of calls the speed of calls and other complex behaviours to attract mates. The fittest males will have the deepest croaks and the best territories, with females known to make their mate choices at last partly based on the males depth of croaking. This has led to sexual dimorphism, with females being larger than males in 90% of species, males in 10 nd males fighting for groups of females. .