How to Tell the Difference Between Female and Male Frogs

Determining the sex of amphibians, a process known as sexing, can often be quite difficult, as they lack external sex organs. In frogs sexual dimorphism (obvious differences in form, size or color between males and females of the same species) occurs in some species, but in most cases there is little difference between the two sexes. It is easiest to sex frogs during breeding season when the differences between the sexes is most apparent.

Things You'll Need

  • Identification key
  • Field guide to amphibians
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Instructions

    • 1

      Identify your frog using an identification key or a field guide to amphibians. Different types of frogs have different sex characteristics, and it is important to know what type of frog you are attempting to sex before you draw any conclusions.

    • 2

      Listen for calling. In most species, only males will call, though this is not the case in all species.

    • 3

      Compare the sizes of frogs if you have more than one mature member of the same species. Females tend to be larger and rounder, while males are generally smaller and more angular.

    • 4

      Look for "nuptial pads" on the underside of your frogs limbs and toes. Nuptial pads are found on males and allow them to firmly grasp the female when mating. These are generally patches of darkened skin which are rough to the touch.

    • 5

      Compare the size of your frogs' toe pads. The males of many species have enlarged toe pads when compared with those of females.

    • 6

      Use your field guide to determine any additional physical characteristics that may differ between the sexes in your particular frog species. For example, some tree frogs might show differences in color on their throat sacs, and many bullfrogs and green frogs can be sexed by comparing the tympanum (external eardrum) of the males and females.