For most species of frog, males are noticeably smaller than females. Tree frogs generally range from 1-5.5 inches (3-14 centimeters) depending on the precise species.. Females are typically about half an inch longer and slightly heavier than males of the same species. The reason for this has to do with the way frogs mate. Males have to climb all the way onto females' backs to mate, so the female has to be larger so that the male's weight doesn't hurt her. Since male frogs do the vast majority of the croaking (more on this below), they usually have specially-constructed throats designed for this purpose. Most male frogs (including tree frogs) have something called a "vocal sac" on their throats. This sac can inflate full of air like a balloon when the frog croaks. When the frog isn't croaking, the deflated sac may make the skin on the throat seem more thin and baggy than on female frogs. In addition, the skin of the vocal sac will often be a different color than the rest of the underside. Yellowish or black shades are common. Instead of having ears that stick out from their heads like humans, frogs' ears are flat discs of skin on the sides of their heads behind their eyes. These discs are sometimes (but not always) a different color than the skin around them. Male frogs tend to have ears that are larger than their eyes. By contrast, female frogs tend to have ears that are about the same size as their eyes (or slightly smaller. Male frogs (including tree frogs) often have special features on their hands and arms that make it easier to cling to female frogs' backs for mating purposes. For example, male frogs sometimes have a patch of rough, raised flesh on each of their thumbs. If the thumb seems to be larger and thicker than the other digits, especially at its base, the frog is probably a male. This feature may be difficult to see except in the breeding season, when it enlarges in time for mating. There are many other external features that can vary between male and female frogs. A few of these are listed below. These vary between species: some frogs may have them and others may not. Some are also time-dependant — for example, the hand hooks described below often develop only during the mating season.  Some male frogs will have thicker arms with more noticeable muscle definition. Some male frogs will develop hook-shaped adornments on their hands used for gripping onto females for mating purposes. In some species, male frogs will have rougher skin (sometimes with small spines) while female frogs will have smooth skin.
قس حجمه. ابحث عن الكيس الصوتي. تفقد حجم الآذان. ابحث عن البطانات الموجودة بجانب الإبهام. ابحث عن الاختلافات الشكلية الأقل شيوعًا.