Instructions
Look at the beak. The beaks on male and female finches are often the easiest way to determine sex. Look for differences in color and vibrancy. A more vibrant beak can often indicate a male bird. A male zebra finch will always have a red beak. Female zebra finch beaks are a lighter orange color. The beaks of male java finches are swollen at the base and appear wider than the beak on a female.
Look at the markings. Male birds are often more colorful than females, displaying vibrant colors and patterns on their feathers. Female finches usually have plainer coloring with more subtle markings. It can be difficult to tell the difference in some finch species. The chest color on a male Gouldian finch is purple, whereas the female chest is a softer mauve color. American goldfinches make it more obvious, with the males turning a vibrant yellow during breeding season while the females remain a dull yellow brown color.
Compare the finch with others. Visit a pet store and look at several similar finches. Seeing both genders will make it easier to distinguish the differences in markings and beak color.
Listen for a song. For most finch species, only the males sing. According to Avian Web, hearing a song is the most accurate way to identify a male Java finch. To encourage the finch to sing, isolate it from other birds. An isolated male is likely to start singing after a week.
How Can I Tell a Finch's Gender?
Birds do not have sex organs like mammals. You will not discover the gender of a finch by looking under its tail. Instead, finches, like most birds, display their gender for all to see in their color and markings.